# New records of Micromegistus bakeri, Trägårdh 1948
(Acari: Mesostigmata: Parantennulidae), a mite
symbiotic on carabid beetles, and notes on the species'
distribution and host specificity

Nia Riggins, Monica R Young, Tanya Renner, Frédéric Beaulieu, Michael
Skvarla

► To cite this version:

Nia Riggins, Monica R Young, Tanya Renner, Frédéric Beaulieu, Michael Skvarla. New records of Micromegistus bakeri, Trägårdh 1948 (Acari: Mesostigmata: Parantennulidae), a mite symbiotic on carabid beetles, and notes on the species' distribution and host specificity. Acarologia, 2024, 64 (2), pp.575-591. 10.24349/40qb-lv0m. hal-04582907

HAL Id: hal-04582907

https://hal.science/hal-04582907

Submitted on 22 May 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
# New records of Micromegistus bakeri, Trägårdh 1948
(Acari: Mesostigmata: Parantennulidae), a mite
symbiotic on carabid beetles, and notes on the species'
distribution and host specificity

Nia Riggins, Monica R Young, Tanya Renner, Frédéric Beaulieu, Michael
Skvarla

<figure><img src="image_1.png" /></figure>

► To cite this version:

Nia Riggins, Monica R Young, Tanya Renner, Frédéric Beaulieu, Michael Skvarla. New records of Micromegistus bakeri, Trägårdh 1948 (Acari: Mesostigmata: Parantennulidae), a mite symbiotic on carabid beetles, and notes on the species' distribution and host specificity. Acarologia, 2024, 64 (2), pp.575-591. 10.24349/40qb-lv0m. hal-04582907

HAL Id: hal-04582907

https://hal.science/hal-04582907v1

Submitted on 22 May 2024

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_2.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
Acarologia

Open Science
in Acarology

# New records of *Micromegistus bakeri*, Trägårdh 1948 (Acari: Mesostigmata: Parantennulidae), a mite symbiotic on carabid beetles, and notes on the species' distribution and host specificity

Nia Riggins IDª, Monica R. Young IDᵇ, Tanya Renner IDª, Frédéric Beaulieu IDᵇ, Michael Skvarla IDª

## Original research

### ABSTRACT

*Micromegistus bakeri* is a purported commensal mite that spends most of its life on the ground beetle *Scarites subterraneus*. It is thought to sustain itself by feeding on the beetle's dermal fluids and opportunistically scavenging on nearby organic debris, although the nature of this relationship, and whether it's beneficial, detrimental or neutral to the host, is unclear. This species has previously been recorded in Mississippi, Texas, and Kansas. This study reports the first record of *M. bakeri* in Pennsylvania based on our collecting, as well as the first records for Ohio, Michigan, Missouri, Arizona, and Canada, based on previously unpublished museum records. The literature and our own survey of carabid beetles indicate that *M. bakeri* has a strong preference for *S. subterraneus* as a host and is not common on other carabids. Our own data shows a prevalence of 27% of *S. subterraneus* (10 out of 37) carrying *M. bakeri*, with an average of 3.1 (range 1–8) mites per infested beetle; none of the other 31 carabid species collected during this study carried *M. bakeri*. This study represents the first publicly available COI barcode sequence for this taxon. We also provide photographs of live mites and summarize suspected sightings from additional locations across North America obtained via the citizen science websites BugGuide and iNaturalist. These records indicate that *M. bakeri* is present throughout the known distribution of its beetle host. Suspected *M. bakeri* were observed on other *Scarites* species in North America, but their presence on these hosts needs to be confirmed via examination of physical specimens. It should be noted that the westernmost record for the species is in Arizona, based on a male specimen that exhibits 6.6% divergence in COI barcode sequence with specimens from Pennsylvania. The specimen is otherwise essentially morphologically identical to males of eastern USA, and it is therefore uncertain whether it represents a cryptic species or merely high intraspecific genetic divergence over a large geographic distance.

**Keywords** symbiotic mites; Carabidae; Parantennulidae; Pennsylvania

### Introduction

Parantennulidae is one of 21 families of mesostigmatic mites (Acari: Parasitiformes) that belong to the infraorder Antennophorina (Trigynaspida), a taxonomically diverse lineage of

Received 15 February 2024

Accepted 23 April 2024

Published 30 April 2024

Corresponding author

Michael Skvarla ID:
mxs1578@psu.edu

Frédéric Beaulieu ID

Michael Skvarla ID
contributed equally to this study

Academic editor

Faraji, Farid

https://doi.org/10.24349/40qb-lv0m

ISSN 0044-586X (print)

ISSN 2107-7207 (electronic)

<figure><img src="image_2.png" /></figure>

Riggins N. et al.

Licensed under

Creative Commons CC-BY 4.0

<footnote>ªThe Pennsylvania State University, Department of Entomology, 501 ASI Building University Park, PA 16802, USA.</footnote>

<footnote>ᵇCanadian National Collection of Insects, Arachnids, and Nematodes, Science and Technology Branch, Agriculture and Agri-Food Canada, 960 Carling Avenue, K.W. Neatby bldg., Ottawa, Ontario, K1A 0C6, Canada.</footnote>
Acarologia

Open Science
in Acarology

# New records of *Micromegistus bakeri*, Trägårdh 1948 (Acari: Mesostigmata: Parantennulidae), a mite symbiotic on carabid beetles, and notes on the species' distribution and host specificity

Nia Riggins IDª, Monica R. Young IDᵇ, Tanya Renner IDª, Frédéric Beaulieu IDᵇ, Michael Skvarla IDª

## Original research

### ABSTRACT

*Micromegistus bakeri* is a purported commensal mite that spends most of its life on the ground beetle *Scarites subterraneus*. It is thought to sustain itself by feeding on the beetle's dermal fluids and opportunistically scavenging on nearby organic debris, although the nature of this relationship, and whether it's beneficial, detrimental or neutral to the host, is unclear. This species has previously been recorded in Mississippi, Texas, and Kansas. This study reports the first record of *M. bakeri* in Pennsylvania based on our collecting, as well as the first records for Ohio, Michigan, Missouri, Arizona, and Canada, based on previously unpublished museum records. The literature and our own survey of carabid beetles indicate that *M. bakeri* has a strong preference for *S. subterraneus* as a host and is not common on other carabids. Our own data shows a prevalence of 27% of *S. subterraneus* (10 out of 37) carrying *M. bakeri*, with an average of 3.1 (range 1–8) mites per infested beetle; none of the other 31 carabid species collected during this study carried *M. bakeri*. This study represents the first publicly available COI barcode sequence for this taxon. We also provide photographs of live mites and summarize suspected sightings from additional locations across North America obtained via the citizen science websites BugGuide and iNaturalist. These records indicate that *M. bakeri* is present throughout the known distribution of its beetle host. Suspected *M. bakeri* were observed on other *Scarites* species in North America, but their presence on these hosts needs to be confirmed via examination of physical specimens. It should be noted that the westernmost record for the species is in Arizona, based on a male specimen that exhibits 6.6% divergence in COI barcode sequence with specimens from Pennsylvania. The specimen is otherwise essentially morphologically identical to males of eastern USA, and it is therefore uncertain whether it represents a cryptic species or merely high intraspecific genetic divergence over a large geographic distance.

**Keywords** symbiotic mites; Carabidae; Parantennulidae; Pennsylvania

### Introduction

Parantennulidae is one of 21 families of mesostigmatic mites (Acari: Parasitiformes) that belong to the infraorder Antennophorina (Trigynaspida), a taxonomically diverse lineage of

Received 15 February 2024

Accepted 23 April 2024

Published 30 April 2024

Corresponding author

Michael Skvarla ID:
mxs1578@psu.edu

Frédéric Beaulieu ID

Michael Skvarla ID
contributed equally to this study

Academic editor

Faraji, Farid

https://doi.org/10.24349/40qb-lv0m

ISSN 0044-586X (print)

ISSN 2107-7207 (electronic)

<figure><img src="image_3.png" /></figure>

Riggins N. et al.

Licensed under

Creative Commons CC-BY 4.0

<footnote>ªThe Pennsylvania State University, Department of Entomology, 501 ASI Building University Park, PA 16802, USA.</footnote>

<footnote>ᵇCanadian National Collection of Insects, Arachnids, and Nematodes, Science and Technology Branch, Agriculture and Agri-Food Canada, 960 Carling Avenue, K.W. Neatby bldg., Ottawa, Ontario, K1A 0C6, Canada.</footnote>
symbiotic mites (Kim 2004). Most antennophorine mites are associated with passalid, carabid and scolytine beetles, as well as ants and myriapods, and are generally considered commensals – if not mutualists, when feeding on potential parasites or pathogens on the host or in its nest – with little or no evidence for hurting their hosts, although many species are kleptoparasitic, with unknown impact on their host (Seeman and Walter 2023). The taxonomic diversity of Antennophorina is concentrated in tropical-subtropical regions, although a few families have representatives in temperate regions, including Parantennulidae. The family includes two monotypic genera, *Parantennulus* Berlese, 1903, and *Diplopodophilus* Willmann, 1940, which are both associated with myriapods, and three described species of *Micromegistus* Trägårdh, 1948, all of which are associated with ground beetles (Coleoptera: Carabidae) (Kim and Castagnoli 2010). *Micromegistus gourlayi* Womersley, 1958 was described from New Zealand on *Mecodema* sp. (Broscinae) (Kim and Castagnoli 2010; Womersley 1958) and the same species, or a close relative (identified as *Micromegistus cf. gourlayi*), was found in Australian caves in the same area as two large pterostichine carabids (Hamilton-Smith 1967). *Micromegistus viduus* (Berlese, 1888) occurs on *Scarites* sp. in South America (Berlese 1888, Kim and Castagnoli 2010), whereas *M. bakeri* Trägårdh, 1948, the focus of this paper, is known primarily from *Scarites subterraneus* Fabricius, 1775. Additionally, there are undescribed *Micromegistus* species associated with ground beetles in Australia (Seeman and Nahrung 2000; O. Seeman pers. comm. 2024) and leafcutter ants in Brazil (Kim and Castagnoli 2010), and a possible *Micromegistus* that was photographed on a tenebrionid in Australia (Lambert 2023).

*Micromegistus bakeri* was first described from adult specimens collected from *Scarites subterraneus* (Carabidae: Scaritinae; Figures 1–2) in Mississippi (Trägårdh 1948). Following this discovery, *M. bakeri* was reported from Kansas by Nickel and Elzinga (1970a), who redescribed the species and detailed most of our current knowledge about its natural history, including feeding biology. They confirmed that *M. bakeri* occurred most frequently on *S. subterraneus*, but also reported a few individuals from two other carabid species: *Cyclotrachelus sodalis* (LeConte, 1846) (reported as *Evarthus sodalis colossus* in their study), and *Patrobus longicornis* (Say, 1823). Since then, *M. bakeri* was subsequently reported from Padre Island, Texas (McDaniel and Bolen 1979), but has otherwise received no other scientific study. It has not been reported from any of the six other species of *Scarites* in North America north of Mexico.

We address this knowledge gap in several ways. First, we present the first record of *M. bakeri* from Pennsylvania, which represents the easternmost record of this species, and report the results of a survey of local carabid fauna for *M. bakeri*. We also summarize previously unreported museum records of *M. bakeri* from Ohio, Michigan, and Missouri, along with suspected records based on photographs of specimens from community science websites. Using this data, we provide a distributional map of all confirmed and suspected *M. bakeri* localities overlaid on the range of *Scarites* spp. found in the United States and Canada. Furthermore, we provide digital photographs of live *M. bakeri* specimens, as well as the first publicly available COI barcode sequence for this taxon.

# Material and methods

## Museum specimen data

Major specimen collections in the USA were consulted for data on *Micromegistus bakeri*, including the Ohio State University Acarology Collection (OSAL) and the United States National Museum (USNM). The species identity of specimens was not verified by us but was considered reliable as they were identified by previous experts, including J.H. Camin, Beverly Gerdeman, Donald E. Johnston, and Richard C. Funk. The Canadian National Collection of Insects, Arachnids and Nematodes (CNC) and Frost Entomological Museum (PSUC) were also consulted but had no specimens of *M. bakeri*. Museum abbreviations follow Evenhuis (2024).
symbiotic mites (Kim 2004). Most antennophorine mites are associated with passalid, carabid and scolytine beetles, as well as ants and myriapods, and are generally considered commensals – if not mutualists, when feeding on potential parasites or pathogens on the host or in its nest – with little or no evidence for hurting their hosts, although many species are kleptoparasitic, with unknown impact on their host (Seeman and Walter 2023). The taxonomic diversity of Antennophorina is concentrated in tropical-subtropical regions, although a few families have representatives in temperate regions, including Parantennulidae. The family includes two monotypic genera, *Parantennulus* Berlese, 1903, and *Diplopodophilus* Willmann, 1940, which are both associated with myriapods, and three described species of *Micromegistus* Trägårdh, 1948, all of which are associated with ground beetles (Coleoptera: Carabidae) (Kim and Castagnoli 2010). *Micromegistus gourlayi* Womersley, 1958 was described from New Zealand on *Mecodema* sp. (Broscinae) (Kim and Castagnoli 2010; Womersley 1958) and the same species, or a close relative (identified as *Micromegistus cf. gourlayi*), was found in Australian caves in the same area as two large pterostichine carabids (Hamilton-Smith 1967). *Micromegistus viduus* (Berlese, 1888) occurs on *Scarites* sp. in South America (Berlese 1888, Kim and Castagnoli 2010), whereas *M. bakeri* Trägårdh, 1948, the focus of this paper, is known primarily from *Scarites subterraneus* Fabricius, 1775. Additionally, there are undescribed *Micromegistus* species associated with ground beetles in Australia (Seeman and Nahrung 2000; O. Seeman pers. comm. 2024) and leafcutter ants in Brazil (Kim and Castagnoli 2010), and a possible *Micromegistus* that was photographed on a tenebrionid in Australia (Lambert 2023).

*Micromegistus bakeri* was first described from adult specimens collected from *Scarites subterraneus* (Carabidae: Scaritinae; Figures 1–2) in Mississippi (Trägårdh 1948). Following this discovery, *M. bakeri* was reported from Kansas by Nickel and Elzinga (1970a), who redescribed the species and detailed most of our current knowledge about its natural history, including feeding biology. They confirmed that *M. bakeri* occurred most frequently on *S. subterraneus*, but also reported a few individuals from two other carabid species: *Cyclotrachelus sodalis* (LeConte, 1846) (reported as *Evarthus sodalis colossus* in their study), and *Patrobus longicornis* (Say, 1823). Since then, *M. bakeri* was subsequently reported from Padre Island, Texas (McDaniel and Bolen 1979), but has otherwise received no other scientific study. It has not been reported from any of the six other species of *Scarites* in North America north of Mexico.

We address this knowledge gap in several ways. First, we present the first record of *M. bakeri* from Pennsylvania, which represents the easternmost record of this species, and report the results of a survey of local carabid fauna for *M. bakeri*. We also summarize previously unreported museum records of *M. bakeri* from Ohio, Michigan, and Missouri, along with suspected records based on photographs of specimens from community science websites. Using this data, we provide a distributional map of all confirmed and suspected *M. bakeri* localities overlaid on the range of *Scarites* spp. found in the United States and Canada. Furthermore, we provide digital photographs of live *M. bakeri* specimens, as well as the first publicly available COI barcode sequence for this taxon.

# Material and methods

## Museum specimen data

Major specimen collections in the USA were consulted for data on *Micromegistus bakeri*, including the Ohio State University Acarology Collection (OSAL) and the United States National Museum (USNM). The species identity of specimens was not verified by us but was considered reliable as they were identified by previous experts, including J.H. Camin, Beverly Gerdeman, Donald E. Johnston, and Richard C. Funk. The Canadian National Collection of Insects, Arachnids and Nematodes (CNC) and Frost Entomological Museum (PSUC) were also consulted but had no specimens of *M. bakeri*. Museum abbreviations follow Evenhuis (2024).
## Beetle field collection and identification

Ground beetles were collected at Stone Valley East Entrance in Pennsylvania, Centre County, State College (40°39′46.7" N 77°54′33.4" W) (Riggins 2023). Beetles were located by walking along a concrete path with a flashlight after dark, after which they were collected by hand. Non-*Scarites* specimens were collected from April through October 2021. Two *Scarites* were collected in September 2021, while the remaining *Scarites* specimens were collected in May and June 2022. Non-*Scarites* carabids were euthanized via freezing and stored at -20 °C until they could be examined under an Olympus SZ-6145TR Trinocular Stereo Microscope for mites. *Scarites* specimens were kept alive and reared following the protocols outlined below. Ground beetles were identified to species using published keys (Ball and Bousquet 2000, Ciegler 2000).

No collection permit was needed due to the field site being on Pennsylvania State University property.

## Colony upkeep

*Scarites subterraneus* were kept in individual plastic containers containing Eco Earth Loose Coconut Fiber Substrate (Zoo Med, San Luis Obispo, CA) and fed Organix® Organic Chicken Flavor Dog Cookies (Castor & Pollux, Clackamas, OR). A folded paper towel was dampened and placed on one side of the container to add moisture to the habitat. Water was also added directly to one side of the container to keep half the substrate moist. The food and towel were changed twice weekly or when mold became evident in the enclosure. The substrate was changed completely once a month. The container was kept in the lab on a shelf near a window. Beetles and mites lived in the lab from mid-September 2021 to late March 2022 and May 2022 to mid-April 2023, representing two different sets of beetles.

## Specimen photography

The specimens were observed and photographed in petri dishes using an Olympus SZ-6145TR Trinocular Stereo Microscope 0.67x – 4.5x with an attached 10 MP Olympus Camera. The photographs were processed, and measurements conducted using the Olympus cellSens Standard 1.18 (Build 16686) Imaging Software.

## Morphology- and DNA-based mite identification

Several mite specimens were removed from a single *S. subterraneus* specimen, stored in 70% ethanol and sent to the Ottawa Research and Development Centre (ORDC), Agriculture and Agri-Food Canada (Ottawa, Ontario, Canada) for identification. Mites were slide-mounted in a polyvinyl alcohol medium and identified under a Leica DM5500B compound microscope equipped with differential interference contrast, using the literature (Kethley 1977; Kim and Castagnoli 2010; Nickel and Elzinga 1970a).

The DNA barcode region of cytochrome *c* oxidase I gene (Hebert *et al.* 2003) was sequenced from a single mite (CNC1898834) at the ORDC's Sequencing Facility using the LCO1490 and HCO2198 primer pair (Folmer *et al.* 1994) following protocols outlined in Nowell and Schwarzfeld (2019) with the following exceptions. PCR amplification was performed in 7.5 µL reaction volumes comprised of 3.75 µL 2X Multiplex PCR Master Mix (QIAGEN Inc.), 0.075 µL (10 µM) of each primer, 2.35 µL of ddH₂O, and 1.25 µL of template DNA. Sequencing reactions were performed in 10 µL reaction volumes with 9 µL of 1:8 diluted (per the manufacturers protocol) BrilliantDye Terminator v3.1 (Edge Biosystem), 0.34 µL ddH₂O, 0.16 µL primer, and 1 µL purified PCR product. Following extraction, the DNA was archived at -80 °C and the voucher specimen was recovered and deposited in the Canadian National Collection of Insects, Arachnids, and Nematodes (CNC), Agriculture and Agri-Food Canada (Ottawa, Canada). The sequence was assembled and edited in Geneious Prime (v. 11.0.3), validated against the Barcode of Life Datasystem's (BOLD) reference library through the
## Beetle field collection and identification

Ground beetles were collected at Stone Valley East Entrance in Pennsylvania, Centre County, State College (40°39′46.7" N 77°54′33.4" W) (Riggins 2023). Beetles were located by walking along a concrete path with a flashlight after dark, after which they were collected by hand. Non-*Scarites* specimens were collected from April through October 2021. Two *Scarites* were collected in September 2021, while the remaining *Scarites* specimens were collected in May and June 2022. Non-*Scarites* carabids were euthanized via freezing and stored at -20 °C until they could be examined under an Olympus SZ-6145TR Trinocular Stereo Microscope for mites. *Scarites* specimens were kept alive and reared following the protocols outlined below. Ground beetles were identified to species using published keys (Ball and Bousquet 2000, Ciegler 2000).

No collection permit was needed due to the field site being on Pennsylvania State University property.

## Colony upkeep

*Scarites subterraneus* were kept in individual plastic containers containing Eco Earth Loose Coconut Fiber Substrate (Zoo Med, San Luis Obispo, CA) and fed Organix® Organic Chicken Flavor Dog Cookies (Castor & Pollux, Clackamas, OR). A folded paper towel was dampened and placed on one side of the container to add moisture to the habitat. Water was also added directly to one side of the container to keep half the substrate moist. The food and towel were changed twice weekly or when mold became evident in the enclosure. The substrate was changed completely once a month. The container was kept in the lab on a shelf near a window. Beetles and mites lived in the lab from mid-September 2021 to late March 2022 and May 2022 to mid-April 2023, representing two different sets of beetles.

## Specimen photography

The specimens were observed and photographed in petri dishes using an Olympus SZ-6145TR Trinocular Stereo Microscope 0.67x – 4.5x with an attached 10 MP Olympus Camera. The photographs were processed, and measurements conducted using the Olympus cellSens Standard 1.18 (Build 16686) Imaging Software.

## Morphology- and DNA-based mite identification

Several mite specimens were removed from a single *S. subterraneus* specimen, stored in 70% ethanol and sent to the Ottawa Research and Development Centre (ORDC), Agriculture and Agri-Food Canada (Ottawa, Ontario, Canada) for identification. Mites were slide-mounted in a polyvinyl alcohol medium and identified under a Leica DM5500B compound microscope equipped with differential interference contrast, using the literature (Kethley 1977; Kim and Castagnoli 2010; Nickel and Elzinga 1970a).

The DNA barcode region of cytochrome *c* oxidase I gene (Hebert *et al.* 2003) was sequenced from a single mite (CNC1898834) at the ORDC's Sequencing Facility using the LCO1490 and HCO2198 primer pair (Folmer *et al.* 1994) following protocols outlined in Nowell and Schwarzfeld (2019) with the following exceptions. PCR amplification was performed in 7.5 µL reaction volumes comprised of 3.75 µL 2X Multiplex PCR Master Mix (QIAGEN Inc.), 0.075 µL (10 µM) of each primer, 2.35 µL of ddH₂O, and 1.25 µL of template DNA. Sequencing reactions were performed in 10 µL reaction volumes with 9 µL of 1:8 diluted (per the manufacturers protocol) BrilliantDye Terminator v3.1 (Edge Biosystem), 0.34 µL ddH₂O, 0.16 µL primer, and 1 µL purified PCR product. Following extraction, the DNA was archived at -80 °C and the voucher specimen was recovered and deposited in the Canadian National Collection of Insects, Arachnids, and Nematodes (CNC), Agriculture and Agri-Food Canada (Ottawa, Canada). The sequence was assembled and edited in Geneious Prime (v. 11.0.3), validated against the Barcode of Life Datasystem's (BOLD) reference library through the
Identification Engine, and is publicly accessible through BOLD (SampleID = CNC1898834) and GenBank (Accession = ON257217).

<table><caption>**Table 1** Publicly available records on BugGuide and iNaturalist that show *Scarites* with mites that appear to be *Micromegistus bakeri*. All photographs were accessed from 24 March – 1 April 2024.</caption><thead><tr><td>Taxon</td><td>State/Province</td><td>Date photographed</td><td>Website</td><td>Photographer</td><td>URL</td></tr></thead><tbody><tr><td>S. quadriceps or vicinus</td><td>Alabama</td><td>April 2023</td><td>iNaturalist</td><td>Dakota Underwood</td><td>https://www.inaturalist.org/observations/156007218</td></tr><tr><td>S. subterraneus</td><td>Alabama</td><td>21 April 2019</td><td>iNaturalist</td><td>byalowitz</td><td>https://www.inaturalist.org/observations/22849662</td></tr><tr><td>Scarites sp.</td><td>Arizona</td><td>24 March 2024</td><td>iNaturalist</td><td>epic2012</td><td>https://www.inaturalist.org/observations/203834262</td></tr><tr><td>S. subterraneus</td><td>Arkansas</td><td>16 April 2020</td><td>iNaturalist</td><td>Juniper</td><td>https://www.inaturalist.org/observations/42350972</td></tr><tr><td>S. subterraneus</td><td>Delaware</td><td>23 May 2021</td><td>iNaturalist</td><td>Matthew Sarver</td><td>https://www.inaturalist.org/observations/79968159</td></tr><tr><td>Scarites sp.</td><td>Delaware</td><td>6 May 2021</td><td>iNaturalist</td><td>inbetweenbays</td><td>https://www.inaturalist.org/observations/77693973</td></tr><tr><td>S. quadriceps or vicinus</td><td>Florida</td><td>16 June 2020</td><td>iNaturalist</td><td>Steve Raduns</td><td>https://www.inaturalist.org/observations/49827854</td></tr><tr><td>S. subterraneus</td><td>Florida</td><td>4 June 2022</td><td>iNaturalist</td><td>Josiah Londerée</td><td>https://www.inaturalist.org/observations/120196021</td></tr><tr><td>S. subterraneus</td><td>Florida</td><td>17 August 2022</td><td>iNaturalist</td><td>Peter May</td><td>https://www.inaturalist.org/observations/131323263</td></tr><tr><td>Scarites sp.</td><td>Illinois</td><td>17 June 2022</td><td>iNaturalist</td><td>mhearell</td><td>https://www.inaturalist.org/observations/122463469</td></tr><tr><td>Scarites sp.</td><td>Indiana</td><td>23 July 2021</td><td>iNaturalist</td><td>Sean Verkamp</td><td>https://www.inaturalist.org/observations/88330518</td></tr><tr><td>S. subterraneus</td><td>Iowa</td><td>17 June 2022</td><td>iNaturalist</td><td>Chase G. Mayers</td><td>https://www.inaturalist.org/observations/122388239</td></tr><tr><td>Scarites sp.</td><td>Iowa</td><td>31 May 2020</td><td>iNaturalist</td><td>jadeifinch04</td><td>https://www.inaturalist.org/observations/48517814</td></tr><tr><td>S. quadriceps group</td><td>Kansas</td><td>24 April 2023</td><td>iNaturalist</td><td>Ryan Philbrick</td><td>https://www.inaturalist.org/observations/156458727</td></tr><tr><td>S. subterraneus</td><td>Kansas</td><td>26 May 2019</td><td>iNaturalist</td><td>Ves</td><td>https://www.inaturalist.org/observations/23561142</td></tr><tr><td>Scarites sp.</td><td>Kansas</td><td>18 June 2011</td><td>BugGuide</td><td>Betsy Betroş</td><td>https://bugguide.net/node/view/885691/bgimage</td></tr><tr><td>Scarites sp.</td><td>Kansas</td><td>7 July 2018</td><td>iNaturalist</td><td>nette57</td><td>https://www.inaturalist.org/observations/99839022</td></tr><tr><td>S. quadriceps or vicinus</td><td>Kentucky</td><td>8 May 2021</td><td>iNaturalist</td><td>starpointestudio</td><td>https://www.inaturalist.org/observations/77988964</td></tr><tr><td>S. subterraneus</td><td>Kentucky</td><td>19 June 2023</td><td>iNaturalist</td><td>Sydney Penner</td><td>https://www.inaturalist.org/observations/168428038</td></tr><tr><td>Scarites sp.</td><td>Kentucky</td><td>30 July 2022</td><td>iNaturalist</td><td>Eileen K. Brandon</td><td>https://www.inaturalist.org/observations/129237494</td></tr><tr><td>Scarites sp.</td><td>Kentucky</td><td>18 May 2022</td><td>iNaturalist</td><td>Sydney Penner</td><td>https://www.inaturalist.org/observations/117663578</td></tr><tr><td>Scarites sp.</td><td>Kentucky</td><td>8 February 2023</td><td>iNaturalist</td><td>Ethan Wells</td><td>https://www.inaturalist.org/observations/148347926</td></tr><tr><td>S. quadriceps group</td><td>Louisiana</td><td>31 May 2020</td><td>iNaturalist</td><td>Zoology123</td><td>https://www.inaturalist.org/observations/48085211</td></tr><tr><td>Scarites sp.</td><td>Louisiana</td><td>16 December 2016</td><td>iNaturalist</td><td>James Erdmann</td><td>https://www.inaturalist.org/observations/4784074</td></tr><tr><td>Scarites sp.</td><td>Louisiana</td><td>24 June 2023</td><td>iNaturalist</td><td>Royal Tyler</td><td>https://www.inaturalist.org/observations/169484561</td></tr><tr><td>S. quadriceps or vicinus</td><td>Maryland</td><td>15 June 2022</td><td>iNaturalist</td><td>Adrienne van den Beemt</td><td>https://www.inaturalist.org/observations/122005614</td></tr><tr><td>S. subterraneus</td><td>Maryland</td><td>15 March 2024</td><td>iNaturalist</td><td>beetcavy</td><td>https://www.inaturalist.org/observations/202550354</td></tr><tr><td>S. subterraneus</td><td>Maryland</td><td>July 2023</td><td>iNaturalist</td><td>Kevin Speray</td><td>https://www.inaturalist.org/observations/172779328</td></tr><tr><td>Scarites sp.</td><td>Maryland</td><td>14 May 2021</td><td>iNaturalist</td><td>laurabankey</td><td>https://www.inaturalist.org/observations/78744611</td></tr><tr><td>Scarites sp.</td><td>Maryland</td><td>20 May 2022</td><td>BugGuide</td><td>Jim Moore</td><td>https://bugguide.net/node/view/2120072/bgimage</td></tr><tr><td>S. subterraneus</td><td>Mississippi</td><td>13 August 2021</td><td>iNaturalist</td><td>Safron</td><td>https://www.inaturalist.org/observations/91027319</td></tr><tr><td>S. subterraneus</td><td>Missouri</td><td>6 June 2023</td><td>iNaturalist</td><td>cararogers</td><td>https://www.inaturalist.org/observations/166036883</td></tr><tr><td>S. subterraneus</td><td>Missouri</td><td>24 May 2015</td><td>iNaturalist</td><td>Lee Elliott</td><td>https://www.inaturalist.org/observations/1538353</td></tr><tr><td>S. subterraneus</td><td>Missouri</td><td>15 April 2019</td><td>iNaturalist</td><td>lazarus</td><td>https://www.inaturalist.org/observations/19487311</td></tr><tr><td>S. subterraneus</td><td>Missouri</td><td>26 April 2019</td><td>iNaturalist</td><td>Neil Shelley</td><td>https://www.inaturalist.org/observations/23291288</td></tr><tr><td>Scarites sp.</td><td>Missouri</td><td>21 July 2017</td><td>BugGuide</td><td>Bob Kipfer</td><td>https://bugguide.net/node/view/1408837/bgimage</td></tr><tr><td>S. subterraneus</td><td>Nebraska</td><td>19 May 2022</td><td>iNaturalist</td><td>amberexplores15</td><td>https://www.inaturalist.org/observations/117800096</td></tr><tr><td>S. subterraneus</td><td>Nebraska</td><td>22 May 2021</td><td>iNaturalist</td><td>Bennett Grappone</td><td>https://www.inaturalist.org/observations/81094572</td></tr><tr><td>S. subterraneus</td><td>New Jersey</td><td>May 2021</td><td>iNaturalist</td><td>geosesarma</td><td>https://www.inaturalist.org/observations/122697064</td></tr><tr><td>S. subterraneus</td><td>New Jersey</td><td>5 May 2018</td><td>iNaturalist</td><td>malachoudoufu</td><td>https://www.inaturalist.org/observations/12722433</td></tr><tr><td>S. subterraneus</td><td>New Jersey</td><td>2 October 2010</td><td>BugGuide</td><td>John R. Maxwell</td><td>https://bugguide.net/node/view/461809</td></tr><tr><td>S. subterraneus</td><td>New Jersey</td><td>17 May 2020</td><td>iNaturalist</td><td>Ellie Nir</td><td>https://www.inaturalist.org/observations/46781128</td></tr><tr><td>Scarites sp.</td><td>New Jersey</td><td>June 2022</td><td>iNaturalist</td><td>geosesarma</td><td>https://www.inaturalist.org/observations/80035119</td></tr><tr><td>Scarites sp.</td><td>New Jersey</td><td>12 September 2020</td><td>iNaturalist</td><td>Vince E</td><td>https://www.inaturalist.org/observations/32612391</td></tr><tr><td>S. quadriceps or vicinus</td><td>North Carolina</td><td>May 2018</td><td>iNaturalist</td><td>David</td><td>https://www.inaturalist.org/observations/32028564</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>3 May 2023</td><td>iNaturalist</td><td>Larry Chen</td><td>https://www.inaturalist.org/observations/159413863</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>25 August 2022</td><td>iNaturalist</td><td>fhodges</td><td>https://www.inaturalist.org/observations/134363452</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>23 October 2020</td><td>iNaturalist</td><td>gmskupien</td><td>https://www.inaturalist.org/observations/63360016</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>31 May 2020</td><td>iNaturalist</td><td>Jason Travis Watanabe Medaris</td><td>https://www.inaturalist.org/observations/48078459</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>3 May 2020</td><td>iNaturalist</td><td>Mabel Surber</td><td>https://www.inaturalist.org/observations/45093927</td></tr><tr><td>Scarites sp.</td><td>North Carolina</td><td>April 2019</td><td>iNaturalist</td><td>Suzanne Cadwell</td><td>https://www.inaturalist.org/observations/23269796</td></tr><tr><td>Scarites sp.</td><td>North Carolina</td><td>21 April 2022</td><td>iNaturalist</td><td>Tim Lewis</td><td>https://www.inaturalist.org/observations/112434818</td></tr><tr><td>S. quadriceps or vicinus</td><td>Ohio</td><td>3 July 2019</td><td>iNaturalist</td><td>srmyers</td><td>https://www.inaturalist.org/observations/28146657</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>26 June 2023</td><td>iNaturalist</td><td>Martyn Drabik-Hamshare</td><td>https://www.inaturalist.org/observations/169576346</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>11 July 2022</td><td>iNaturalist</td><td>elliot2868</td><td>https://www.inaturalist.org/observations/125836131</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>May 2021</td><td>iNaturalist</td><td>jessekay7</td><td>https://www.inaturalist.org/observations/79077167</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>May 2022</td><td>iNaturalist</td><td>jessekay7</td><td>https://www.inaturalist.org/observations/117520558</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>May 2023</td><td>iNaturalist</td><td>lilhaus</td><td>https://www.inaturalist.org/observations/164736084</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>31 May 2021</td><td>iNaturalist</td><td>dgphilipps</td><td>https://www.inaturalist.org/observations/81103589</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>March 2024</td><td>iNaturalist</td><td>Madelyn Snyder</td><td>https://www.inaturalist.org/observations/204186491</td></tr><tr><td>Scarites sp.</td><td>Ohio</td><td>17 June 2020</td><td>iNaturalist</td><td>mmnat</td><td>https://www.inaturalist.org/observations/49988920</td></tr></tbody></table>
Identification Engine, and is publicly accessible through BOLD (SampleID = CNC1898834) and GenBank (Accession = ON257217).

<table><caption>**Table 1** Publicly available records on BugGuide and iNaturalist that show *Scarites* with mites that appear to be *Micromegistus bakeri*. All photographs were accessed from 24 March – 1 April 2024.</caption><thead><tr><td>Taxon</td><td>State/Province</td><td>Date photographed</td><td>Website</td><td>Photographer</td><td>URL</td></tr></thead><tbody><tr><td>S. quadriceps or vicinus</td><td>Alabama</td><td>April 2023</td><td>iNaturalist</td><td>Dakota Underwood</td><td>https://www.inaturalist.org/observations/156007218</td></tr><tr><td>S. subterraneus</td><td>Alabama</td><td>21 April 2019</td><td>iNaturalist</td><td>byalowitz</td><td>https://www.inaturalist.org/observations/22849662</td></tr><tr><td>Scarites sp.</td><td>Arizona</td><td>24 March 2024</td><td>iNaturalist</td><td>epic2012</td><td>https://www.inaturalist.org/observations/203834262</td></tr><tr><td>S. subterraneus</td><td>Arkansas</td><td>16 April 2020</td><td>iNaturalist</td><td>Juniper</td><td>https://www.inaturalist.org/observations/42350972</td></tr><tr><td>S. subterraneus</td><td>Delaware</td><td>23 May 2021</td><td>iNaturalist</td><td>Matthew Sarver</td><td>https://www.inaturalist.org/observations/79968159</td></tr><tr><td>Scarites sp.</td><td>Delaware</td><td>6 May 2021</td><td>iNaturalist</td><td>inbetweenbays</td><td>https://www.inaturalist.org/observations/77693973</td></tr><tr><td>S. quadriceps or vicinus</td><td>Florida</td><td>16 June 2020</td><td>iNaturalist</td><td>Steve Raduns</td><td>https://www.inaturalist.org/observations/49827854</td></tr><tr><td>S. subterraneus</td><td>Florida</td><td>4 June 2022</td><td>iNaturalist</td><td>Josiah Londerée</td><td>https://www.inaturalist.org/observations/120196021</td></tr><tr><td>S. subterraneus</td><td>Florida</td><td>17 August 2022</td><td>iNaturalist</td><td>Peter May</td><td>https://www.inaturalist.org/observations/131323263</td></tr><tr><td>Scarites sp.</td><td>Illinois</td><td>17 June 2022</td><td>iNaturalist</td><td>mhearell</td><td>https://www.inaturalist.org/observations/122463469</td></tr><tr><td>Scarites sp.</td><td>Indiana</td><td>23 July 2021</td><td>iNaturalist</td><td>Sean Verkamp</td><td>https://www.inaturalist.org/observations/88330518</td></tr><tr><td>S. subterraneus</td><td>Iowa</td><td>17 June 2022</td><td>iNaturalist</td><td>Chase G. Mayers</td><td>https://www.inaturalist.org/observations/122388239</td></tr><tr><td>Scarites sp.</td><td>Iowa</td><td>31 May 2020</td><td>iNaturalist</td><td>jadeifinch04</td><td>https://www.inaturalist.org/observations/48517814</td></tr><tr><td>S. quadriceps group</td><td>Kansas</td><td>24 April 2023</td><td>iNaturalist</td><td>Ryan Philbrick</td><td>https://www.inaturalist.org/observations/156458727</td></tr><tr><td>S. subterraneus</td><td>Kansas</td><td>26 May 2019</td><td>iNaturalist</td><td>Ves</td><td>https://www.inaturalist.org/observations/23561142</td></tr><tr><td>Scarites sp.</td><td>Kansas</td><td>18 June 2011</td><td>BugGuide</td><td>Betsy Betroş</td><td>https://bugguide.net/node/view/885691/bgimage</td></tr><tr><td>Scarites sp.</td><td>Kansas</td><td>7 July 2018</td><td>iNaturalist</td><td>nette57</td><td>https://www.inaturalist.org/observations/99839022</td></tr><tr><td>S. quadriceps or vicinus</td><td>Kentucky</td><td>8 May 2021</td><td>iNaturalist</td><td>starpointestudio</td><td>https://www.inaturalist.org/observations/77988964</td></tr><tr><td>S. subterraneus</td><td>Kentucky</td><td>19 June 2023</td><td>iNaturalist</td><td>Sydney Penner</td><td>https://www.inaturalist.org/observations/168428038</td></tr><tr><td>Scarites sp.</td><td>Kentucky</td><td>30 July 2022</td><td>iNaturalist</td><td>Eileen K. Brandon</td><td>https://www.inaturalist.org/observations/129237494</td></tr><tr><td>Scarites sp.</td><td>Kentucky</td><td>18 May 2022</td><td>iNaturalist</td><td>Sydney Penner</td><td>https://www.inaturalist.org/observations/117663578</td></tr><tr><td>Scarites sp.</td><td>Kentucky</td><td>8 February 2023</td><td>iNaturalist</td><td>Ethan Wells</td><td>https://www.inaturalist.org/observations/148347926</td></tr><tr><td>S. quadriceps group</td><td>Louisiana</td><td>31 May 2020</td><td>iNaturalist</td><td>Zoology123</td><td>https://www.inaturalist.org/observations/48085211</td></tr><tr><td>Scarites sp.</td><td>Louisiana</td><td>16 December 2016</td><td>iNaturalist</td><td>James Erdmann</td><td>https://www.inaturalist.org/observations/4784074</td></tr><tr><td>Scarites sp.</td><td>Louisiana</td><td>24 June 2023</td><td>iNaturalist</td><td>Royal Tyler</td><td>https://www.inaturalist.org/observations/169484561</td></tr><tr><td>S. quadriceps or vicinus</td><td>Maryland</td><td>15 June 2022</td><td>iNaturalist</td><td>Adrienne van den Beemt</td><td>https://www.inaturalist.org/observations/122005614</td></tr><tr><td>S. subterraneus</td><td>Maryland</td><td>15 March 2024</td><td>iNaturalist</td><td>beetcavy</td><td>https://www.inaturalist.org/observations/202550354</td></tr><tr><td>S. subterraneus</td><td>Maryland</td><td>July 2023</td><td>iNaturalist</td><td>Kevin Speray</td><td>https://www.inaturalist.org/observations/172779328</td></tr><tr><td>Scarites sp.</td><td>Maryland</td><td>14 May 2021</td><td>iNaturalist</td><td>laurabankey</td><td>https://www.inaturalist.org/observations/78744611</td></tr><tr><td>Scarites sp.</td><td>Maryland</td><td>20 May 2022</td><td>BugGuide</td><td>Jim Moore</td><td>https://bugguide.net/node/view/2120072/bgimage</td></tr><tr><td>S. subterraneus</td><td>Mississippi</td><td>13 August 2021</td><td>iNaturalist</td><td>Safron</td><td>https://www.inaturalist.org/observations/91027319</td></tr><tr><td>S. subterraneus</td><td>Missouri</td><td>6 June 2023</td><td>iNaturalist</td><td>cararogers</td><td>https://www.inaturalist.org/observations/166036883</td></tr><tr><td>S. subterraneus</td><td>Missouri</td><td>24 May 2015</td><td>iNaturalist</td><td>Lee Elliott</td><td>https://www.inaturalist.org/observations/1538353</td></tr><tr><td>S. subterraneus</td><td>Missouri</td><td>15 April 2019</td><td>iNaturalist</td><td>lazarus</td><td>https://www.inaturalist.org/observations/19487311</td></tr><tr><td>S. subterraneus</td><td>Missouri</td><td>26 April 2019</td><td>iNaturalist</td><td>Neil Shelley</td><td>https://www.inaturalist.org/observations/23291288</td></tr><tr><td>Scarites sp.</td><td>Missouri</td><td>21 July 2017</td><td>BugGuide</td><td>Bob Kipfer</td><td>https://bugguide.net/node/view/1408837/bgimage</td></tr><tr><td>S. subterraneus</td><td>Nebraska</td><td>19 May 2022</td><td>iNaturalist</td><td>amberexplores15</td><td>https://www.inaturalist.org/observations/117800096</td></tr><tr><td>S. subterraneus</td><td>Nebraska</td><td>22 May 2021</td><td>iNaturalist</td><td>Bennett Grappone</td><td>https://www.inaturalist.org/observations/81094572</td></tr><tr><td>S. subterraneus</td><td>New Jersey</td><td>May 2021</td><td>iNaturalist</td><td>geosesarma</td><td>https://www.inaturalist.org/observations/122697064</td></tr><tr><td>S. subterraneus</td><td>New Jersey</td><td>5 May 2018</td><td>iNaturalist</td><td>malachoudoufu</td><td>https://www.inaturalist.org/observations/12722433</td></tr><tr><td>S. subterraneus</td><td>New Jersey</td><td>2 October 2010</td><td>BugGuide</td><td>John R. Maxwell</td><td>https://bugguide.net/node/view/461809</td></tr><tr><td>S. subterraneus</td><td>New Jersey</td><td>17 May 2020</td><td>iNaturalist</td><td>Ellie Nir</td><td>https://www.inaturalist.org/observations/46781128</td></tr><tr><td>Scarites sp.</td><td>New Jersey</td><td>June 2022</td><td>iNaturalist</td><td>geosesarma</td><td>https://www.inaturalist.org/observations/80035119</td></tr><tr><td>Scarites sp.</td><td>New Jersey</td><td>12 September 2020</td><td>iNaturalist</td><td>Vince E</td><td>https://www.inaturalist.org/observations/32612391</td></tr><tr><td>S. quadriceps or vicinus</td><td>North Carolina</td><td>May 2018</td><td>iNaturalist</td><td>David</td><td>https://www.inaturalist.org/observations/32028564</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>3 May 2023</td><td>iNaturalist</td><td>Larry Chen</td><td>https://www.inaturalist.org/observations/159413863</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>25 August 2022</td><td>iNaturalist</td><td>fhodges</td><td>https://www.inaturalist.org/observations/134363452</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>23 October 2020</td><td>iNaturalist</td><td>gmskupien</td><td>https://www.inaturalist.org/observations/63360016</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>31 May 2020</td><td>iNaturalist</td><td>Jason Travis Watanabe Medaris</td><td>https://www.inaturalist.org/observations/48078459</td></tr><tr><td>S. subterraneus</td><td>North Carolina</td><td>3 May 2020</td><td>iNaturalist</td><td>Mabel Surber</td><td>https://www.inaturalist.org/observations/45093927</td></tr><tr><td>Scarites sp.</td><td>North Carolina</td><td>April 2019</td><td>iNaturalist</td><td>Suzanne Cadwell</td><td>https://www.inaturalist.org/observations/23269796</td></tr><tr><td>Scarites sp.</td><td>North Carolina</td><td>21 April 2022</td><td>iNaturalist</td><td>Tim Lewis</td><td>https://www.inaturalist.org/observations/112434818</td></tr><tr><td>S. quadriceps or vicinus</td><td>Ohio</td><td>3 July 2019</td><td>iNaturalist</td><td>srmyers</td><td>https://www.inaturalist.org/observations/28146657</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>26 June 2023</td><td>iNaturalist</td><td>Martyn Drabik-Hamshare</td><td>https://www.inaturalist.org/observations/169576346</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>11 July 2022</td><td>iNaturalist</td><td>elliot2868</td><td>https://www.inaturalist.org/observations/125836131</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>May 2021</td><td>iNaturalist</td><td>jessekay7</td><td>https://www.inaturalist.org/observations/79077167</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>May 2022</td><td>iNaturalist</td><td>jessekay7</td><td>https://www.inaturalist.org/observations/117520558</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>May 2023</td><td>iNaturalist</td><td>lilhaus</td><td>https://www.inaturalist.org/observations/164736084</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>31 May 2021</td><td>iNaturalist</td><td>dgphilipps</td><td>https://www.inaturalist.org/observations/81103589</td></tr><tr><td>S. subterraneus</td><td>Ohio</td><td>March 2024</td><td>iNaturalist</td><td>Madelyn Snyder</td><td>https://www.inaturalist.org/observations/204186491</td></tr><tr><td>Scarites sp.</td><td>Ohio</td><td>17 June 2020</td><td>iNaturalist</td><td>mmnat</td><td>https://www.inaturalist.org/observations/49988920</td></tr></tbody></table>
<table><caption>Table 1 Continued.</caption><thead><tr><th>Taxon</th><th>State/Province</th><th>Date photographed</th><th>Website</th><th>Photographer</th><th>URL</th></tr></thead><tbody><tr><td>S. subterraneus</td><td>Oklahoma</td><td>8 July 2021</td><td>iNaturalist</td><td>Bard</td><td>https://www.inaturalist.org/observations/86245181</td></tr><tr><td>S. subterraneus</td><td>Oklahoma</td><td>1 September 2018</td><td>iNaturalist</td><td>Brian Cross</td><td>https://www.inaturalist.org/observations/16104100</td></tr><tr><td>S. subterraneus</td><td>Oklahoma</td><td>23 July 2007</td><td>BugGuide</td><td>Sam Houston</td><td>https://bugguide.net/node/view/132521</td></tr><tr><td>S. subterraneus</td><td>Oklahoma</td><td>26 April 2021</td><td>iNaturalist</td><td>Ian Kanda</td><td>https://www.inaturalist.org/observations/75396729</td></tr><tr><td>S. subterraneus</td><td>Oklahoma</td><td>7 July 2022</td><td>iNaturalist</td><td>strix_v</td><td>https://www.inaturalist.org/observations/129870212</td></tr><tr><td>Scarites sp.</td><td>Oklahoma</td><td>5 October 2020</td><td>iNaturalist</td><td>Steve Davis</td><td>https://www.inaturalist.org/observations/61756312</td></tr><tr><td>Scarites sp.</td><td>Oklahoma</td><td>28 May 2019</td><td>iNaturalist</td><td>Rick</td><td>https://www.inaturalist.org/observations/25976520</td></tr><tr><td>S. subterraneus</td><td>Ontario</td><td>21 May 2004</td><td>BugGuide</td><td>Robin McLeod</td><td>https://bugguide.net/node/view/51177</td></tr><tr><td>S. subterraneus</td><td>Ontario</td><td>16 July 2021</td><td>iNaturalist</td><td>tberkers</td><td>https://www.inaturalist.org/observations/105322864</td></tr><tr><td>S. subterraneus</td><td>Pennsylvania</td><td>3 July 2019</td><td>iNaturalist</td><td>Scott Camazine</td><td>https://www.inaturalist.org/observations/28145115</td></tr><tr><td>S. subterraneus</td><td>Pennsylvania</td><td>May 2022</td><td>iNaturalist</td><td>Serena Lynne</td><td>https://www.inaturalist.org/observations/161725536</td></tr><tr><td>S. subterraneus</td><td>Pennsylvania</td><td>May 2023</td><td>iNaturalist</td><td>Serena Lynne</td><td>https://www.inaturalist.org/observations/118100012</td></tr><tr><td>S. subterraneus</td><td>Pennsylvania</td><td>23 July 2022</td><td>iNaturalist</td><td>Jeff Stauffer</td><td>https://www.inaturalist.org/observations/127838293</td></tr><tr><td>Scarites sp.</td><td>Pennsylvania</td><td>20 July 2022</td><td>iNaturalist</td><td>Melissa Reckner</td><td>https://www.inaturalist.org/observations/127346039</td></tr><tr><td>Scarites sp.</td><td>Pennsylvania</td><td>27 April 2020</td><td>iNaturalist</td><td>Riverfront North Partnership</td><td>https://www.inaturalist.org/observations/44023380</td></tr><tr><td>Scarites sp.</td><td>Pennsylvania</td><td>31 May 2020</td><td>BugGuide</td><td>Ken Wolgemuth</td><td>https://bugguide.net/node/view/1823792/bgimage</td></tr><tr><td>S. subterraneus</td><td>South Carolina</td><td>28 May 2014</td><td>BugGuide</td><td>S. Mooreman</td><td>https://bugguide.net/node/view/928648</td></tr><tr><td>Scarites sp.</td><td>South Carolina</td><td>16 April 2020</td><td>iNaturalist</td><td>patrickd223</td><td>https://www.inaturalist.org/observations/42347748</td></tr><tr><td>Scarites sp.</td><td>South Carolina</td><td>20 July 2021</td><td>iNaturalist</td><td>Zakary T.</td><td>https://www.inaturalist.org/observations/88051919</td></tr><tr><td>S. quadriceps or vicinus</td><td>Tennessee</td><td>2 May 2019</td><td>iNaturalist</td><td>The Real Mothman</td><td>https://www.inaturalist.org/observations/24422369</td></tr><tr><td>S. subterraneus</td><td>Tennessee</td><td>5 April 2023</td><td>iNaturalist</td><td>samwilhelm</td><td>https://www.inaturalist.org/observations/153636189</td></tr><tr><td>S. subterraneus</td><td>Tennessee</td><td>22 May 2023</td><td>iNaturalist</td><td>Jared Shorma</td><td>https://www.inaturalist.org/observations/191148292</td></tr><tr><td>S. subterraneus</td><td>Tennessee</td><td>29 April 2022</td><td>iNaturalist</td><td>The Real Mothman</td><td>https://www.inaturalist.org/observations/115575467</td></tr><tr><td>S. subterraneus</td><td>Tennessee</td><td>11 April 2020</td><td>iNaturalist</td><td>aworkinger</td><td>https://www.inaturalist.org/observations/41940748</td></tr><tr><td>Scarites sp.</td><td>Tennessee</td><td>April 2021</td><td>iNaturalist</td><td>Breanna Couey</td><td>https://www.inaturalist.org/observations/75345415</td></tr><tr><td>Scarites sp.</td><td>Tennessee</td><td>28 March 2023</td><td>iNaturalist</td><td>Dominic</td><td>https://www.inaturalist.org/observations/152728250</td></tr><tr><td>S. lissopterus</td><td>Texas</td><td>27 June 2017</td><td>BugGuide</td><td>Iustin Cret</td><td>https://bugguide.net/node/view/950830/bgimage</td></tr><tr><td>S. quadriceps group</td><td>Texas</td><td>3 May 2021</td><td>iNaturalist</td><td>Curtis Eckerman</td><td>https://www.inaturalist.org/observations/77281309</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>28 April 2018</td><td>iNaturalist</td><td>Emily Chapman</td><td>https://www.inaturalist.org/observations/11632392</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>3 May 2022</td><td>iNaturalist</td><td>ethan437</td><td>https://www.inaturalist.org/observations/115218255</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>13 October 2021</td><td>iNaturalist</td><td>Caleb Helsel</td><td>https://www.inaturalist.org/observations/98153659</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>3 May 2021</td><td>iNaturalist</td><td>Eric Keith</td><td>https://www.inaturalist.org/observations/77757849</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>21 March 2021</td><td>iNaturalist</td><td>Stephen Kelley</td><td>https://www.inaturalist.org/observations/71809489</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>14 May 2022</td><td>iNaturalist</td><td>Rich Kostecke</td><td>https://www.inaturalist.org/observations/117258404</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>February 2024</td><td>iNaturalist</td><td>Leif</td><td>https://www.inaturalist.org/observations/200041575</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>26 April 2023</td><td>iNaturalist</td><td>Riki Miller</td><td>https://www.inaturalist.org/observations/203487895</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>June 2021</td><td>iNaturalist</td><td>A. Rector</td><td>https://www.inaturalist.org/observations/85254000</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>17 May 2023</td><td>iNaturalist</td><td>A. Rector</td><td>https://www.inaturalist.org/observations/162143901</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>8 June 2019</td><td>iNaturalist</td><td>Martha Russell</td><td>https://www.inaturalist.org/observations/26641621</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>April 2023</td><td>iNaturalist</td><td>Shannon @DirtNKids</td><td>https://www.inaturalist.org/observations/155379149</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>23 April 2015</td><td>iNaturalist</td><td>BJ Stacey</td><td>https://www.inaturalist.org/observations/1516719</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>8 March 2023</td><td>iNaturalist</td><td>assmann</td><td>https://www.inaturalist.org/observations/150615081</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>10 May 2020</td><td>iNaturalist</td><td>birderbrian</td><td>https://www.inaturalist.org/observations/45686023</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>10 September 2022</td><td>iNaturalist</td><td>Scott Buckel</td><td>https://www.inaturalist.org/observations/134536157</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>31 March 2021</td><td>iNaturalist</td><td>jstone66</td><td>https://www.inaturalist.org/observations/72570007</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>22 March 2015</td><td>iNaturalist</td><td>Sam Kieschnick</td><td>https://www.inaturalist.org/observations/1333263</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>22 March 2024</td><td>iNaturalist</td><td>Blake Miller</td><td>https://www.inaturalist.org/observations/156775421</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>14 March 2024</td><td>iNaturalist</td><td>Chris Shuck</td><td>https://www.inaturalist.org/observations/202481557</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>15 September 2020</td><td>iNaturalist</td><td>Michael J. W. Carr</td><td>https://www.inaturalist.org/observations/84501279</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>26 May 2021</td><td>iNaturalist</td><td>Michael J. W. Carr</td><td>https://www.inaturalist.org/observations/59717337</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>17 June 2021</td><td>iNaturalist</td><td>Gray Catanzaro</td><td>https://www.inaturalist.org/observations/100529409</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>September 2022</td><td>iNaturalist</td><td>Dean Firth</td><td>https://www.inaturalist.org/observations/135064425</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>30 August 2023</td><td>iNaturalist</td><td>Bert Harris</td><td>https://www.inaturalist.org/observations/180897649</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>April 2023</td><td>iNaturalist</td><td>Heather</td><td>https://www.inaturalist.org/observations/155028186</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>23 April 2022</td><td>iNaturalist</td><td>Henry</td><td>https://www.inaturalist.org/observations/112557111</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>3 May 2020</td><td>iNaturalist</td><td>Koaw Nature</td><td>https://www.inaturalist.org/observations/44826202</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>12 June 2023</td><td>iNaturalist</td><td>Gideon Snavely</td><td>https://www.inaturalist.org/observations/167197041</td></tr><tr><td>Scarites sp.</td><td>Virginia</td><td>14 May 2021</td><td>iNaturalist</td><td>Mark Richman</td><td>https://www.inaturalist.org/observations/78795746</td></tr><tr><td>S. quadriceps or vicinus</td><td>West Virginia</td><td>August 2019</td><td>iNaturalist</td><td>bensect</td><td>https://www.inaturalist.org/observations/31240371</td></tr><tr><td>S. subterraneus</td><td>West Virginia</td><td>18 May 2021</td><td>iNaturalist</td><td>becksnyc</td><td>https://www.inaturalist.org/observations/79429278</td></tr><tr><td>S. subterraneus</td><td>Wisconsin</td><td>20 May 2021</td><td>iNaturalist</td><td>glcarlton</td><td>https://www.inaturalist.org/observations/79589418</td></tr></tbody></table>

Distribution map

Known localities for *Micromegistus bakeri* in North America were compiled from published literature (Trägårdh 1948; Nickel and Elzinga 1970a; McDaniel and Bolen 1979), as well as specimens housed in the OSAL and vouchered in BOLD. Photographs of *S. subterraneus*; *S. lissopterus* Chaudoir; *S. marinus* Nichols; *S. ocalensis* Nichols; *S. quadriceps* Chaudoir; *S. stenops* Bousquet & Skelley; *S. vicinus* Chaudoir; and unidentified *Scarites* posted to iNaturalist
<table><caption>Table 1 Continued.</caption><thead><tr><th>Taxon</th><th>State/Province</th><th>Date photographed</th><th>Website</th><th>Photographer</th><th>URL</th></tr></thead><tbody><tr><td>S. subterraneus</td><td>Oklahoma</td><td>8 July 2021</td><td>iNaturalist</td><td>Bard</td><td>https://www.inaturalist.org/observations/86245181</td></tr><tr><td>S. subterraneus</td><td>Oklahoma</td><td>1 September 2018</td><td>iNaturalist</td><td>Brian Cross</td><td>https://www.inaturalist.org/observations/16104100</td></tr><tr><td>S. subterraneus</td><td>Oklahoma</td><td>23 July 2007</td><td>BugGuide</td><td>Sam Houston</td><td>https://bugguide.net/node/view/132521</td></tr><tr><td>S. subterraneus</td><td>Oklahoma</td><td>26 April 2021</td><td>iNaturalist</td><td>Ian Kanda</td><td>https://www.inaturalist.org/observations/75396729</td></tr><tr><td>S. subterraneus</td><td>Oklahoma</td><td>7 July 2022</td><td>iNaturalist</td><td>strix_v</td><td>https://www.inaturalist.org/observations/129870212</td></tr><tr><td>Scarites sp.</td><td>Oklahoma</td><td>5 October 2020</td><td>iNaturalist</td><td>Steve Davis</td><td>https://www.inaturalist.org/observations/61756312</td></tr><tr><td>Scarites sp.</td><td>Oklahoma</td><td>28 May 2019</td><td>iNaturalist</td><td>Rick</td><td>https://www.inaturalist.org/observations/25976520</td></tr><tr><td>S. subterraneus</td><td>Ontario</td><td>21 May 2004</td><td>BugGuide</td><td>Robin McLeod</td><td>https://bugguide.net/node/view/51177</td></tr><tr><td>S. subterraneus</td><td>Ontario</td><td>16 July 2021</td><td>iNaturalist</td><td>tberkers</td><td>https://www.inaturalist.org/observations/105322864</td></tr><tr><td>S. subterraneus</td><td>Pennsylvania</td><td>3 July 2019</td><td>iNaturalist</td><td>Scott Camazine</td><td>https://www.inaturalist.org/observations/28145115</td></tr><tr><td>S. subterraneus</td><td>Pennsylvania</td><td>May 2022</td><td>iNaturalist</td><td>Serena Lynne</td><td>https://www.inaturalist.org/observations/161725536</td></tr><tr><td>S. subterraneus</td><td>Pennsylvania</td><td>May 2023</td><td>iNaturalist</td><td>Serena Lynne</td><td>https://www.inaturalist.org/observations/118100012</td></tr><tr><td>S. subterraneus</td><td>Pennsylvania</td><td>23 July 2022</td><td>iNaturalist</td><td>Jeff Stauffer</td><td>https://www.inaturalist.org/observations/127838293</td></tr><tr><td>Scarites sp.</td><td>Pennsylvania</td><td>20 July 2022</td><td>iNaturalist</td><td>Melissa Reckner</td><td>https://www.inaturalist.org/observations/127346039</td></tr><tr><td>Scarites sp.</td><td>Pennsylvania</td><td>27 April 2020</td><td>iNaturalist</td><td>Riverfront North Partnership</td><td>https://www.inaturalist.org/observations/44023380</td></tr><tr><td>Scarites sp.</td><td>Pennsylvania</td><td>31 May 2020</td><td>BugGuide</td><td>Ken Wolgemuth</td><td>https://bugguide.net/node/view/1823792/bgimage</td></tr><tr><td>S. subterraneus</td><td>South Carolina</td><td>28 May 2014</td><td>BugGuide</td><td>S. Mooreman</td><td>https://bugguide.net/node/view/928648</td></tr><tr><td>Scarites sp.</td><td>South Carolina</td><td>16 April 2020</td><td>iNaturalist</td><td>patrickd223</td><td>https://www.inaturalist.org/observations/42347748</td></tr><tr><td>Scarites sp.</td><td>South Carolina</td><td>20 July 2021</td><td>iNaturalist</td><td>Zakary T.</td><td>https://www.inaturalist.org/observations/88051919</td></tr><tr><td>S. quadriceps or vicinus</td><td>Tennessee</td><td>2 May 2019</td><td>iNaturalist</td><td>The Real Mothman</td><td>https://www.inaturalist.org/observations/24422369</td></tr><tr><td>S. subterraneus</td><td>Tennessee</td><td>5 April 2023</td><td>iNaturalist</td><td>samwilhelm</td><td>https://www.inaturalist.org/observations/153636189</td></tr><tr><td>S. subterraneus</td><td>Tennessee</td><td>22 May 2023</td><td>iNaturalist</td><td>Jared Shorma</td><td>https://www.inaturalist.org/observations/191148292</td></tr><tr><td>S. subterraneus</td><td>Tennessee</td><td>29 April 2022</td><td>iNaturalist</td><td>The Real Mothman</td><td>https://www.inaturalist.org/observations/115575467</td></tr><tr><td>S. subterraneus</td><td>Tennessee</td><td>11 April 2020</td><td>iNaturalist</td><td>aworkinger</td><td>https://www.inaturalist.org/observations/41940748</td></tr><tr><td>Scarites sp.</td><td>Tennessee</td><td>April 2021</td><td>iNaturalist</td><td>Breanna Couey</td><td>https://www.inaturalist.org/observations/75345415</td></tr><tr><td>Scarites sp.</td><td>Tennessee</td><td>28 March 2023</td><td>iNaturalist</td><td>Dominic</td><td>https://www.inaturalist.org/observations/152728250</td></tr><tr><td>S. lissopterus</td><td>Texas</td><td>27 June 2017</td><td>BugGuide</td><td>Iustin Cret</td><td>https://bugguide.net/node/view/950830/bgimage</td></tr><tr><td>S. quadriceps group</td><td>Texas</td><td>3 May 2021</td><td>iNaturalist</td><td>Curtis Eckerman</td><td>https://www.inaturalist.org/observations/77281309</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>28 April 2018</td><td>iNaturalist</td><td>Emily Chapman</td><td>https://www.inaturalist.org/observations/11632392</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>3 May 2022</td><td>iNaturalist</td><td>ethan437</td><td>https://www.inaturalist.org/observations/115218255</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>13 October 2021</td><td>iNaturalist</td><td>Caleb Helsel</td><td>https://www.inaturalist.org/observations/98153659</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>3 May 2021</td><td>iNaturalist</td><td>Eric Keith</td><td>https://www.inaturalist.org/observations/77757849</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>21 March 2021</td><td>iNaturalist</td><td>Stephen Kelley</td><td>https://www.inaturalist.org/observations/71809489</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>14 May 2022</td><td>iNaturalist</td><td>Rich Kostecke</td><td>https://www.inaturalist.org/observations/117258404</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>February 2024</td><td>iNaturalist</td><td>Leif</td><td>https://www.inaturalist.org/observations/200041575</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>26 April 2023</td><td>iNaturalist</td><td>Riki Miller</td><td>https://www.inaturalist.org/observations/203487895</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>June 2021</td><td>iNaturalist</td><td>A. Rector</td><td>https://www.inaturalist.org/observations/85254000</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>17 May 2023</td><td>iNaturalist</td><td>A. Rector</td><td>https://www.inaturalist.org/observations/162143901</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>8 June 2019</td><td>iNaturalist</td><td>Martha Russell</td><td>https://www.inaturalist.org/observations/26641621</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>April 2023</td><td>iNaturalist</td><td>Shannon @DirtNKids</td><td>https://www.inaturalist.org/observations/155379149</td></tr><tr><td>S. subterraneus</td><td>Texas</td><td>23 April 2015</td><td>iNaturalist</td><td>BJ Stacey</td><td>https://www.inaturalist.org/observations/1516719</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>8 March 2023</td><td>iNaturalist</td><td>assmann</td><td>https://www.inaturalist.org/observations/150615081</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>10 May 2020</td><td>iNaturalist</td><td>birderbrian</td><td>https://www.inaturalist.org/observations/45686023</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>10 September 2022</td><td>iNaturalist</td><td>Scott Buckel</td><td>https://www.inaturalist.org/observations/134536157</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>31 March 2021</td><td>iNaturalist</td><td>jstone66</td><td>https://www.inaturalist.org/observations/72570007</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>22 March 2015</td><td>iNaturalist</td><td>Sam Kieschnick</td><td>https://www.inaturalist.org/observations/1333263</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>22 March 2024</td><td>iNaturalist</td><td>Blake Miller</td><td>https://www.inaturalist.org/observations/156775421</td></tr><tr><td>Scarites sp.</td><td>Texas</td><td>14 March 2024</td><td>iNaturalist</td><td>Chris Shuck</td><td>https://www.inaturalist.org/observations/202481557</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>15 September 2020</td><td>iNaturalist</td><td>Michael J. W. Carr</td><td>https://www.inaturalist.org/observations/84501279</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>26 May 2021</td><td>iNaturalist</td><td>Michael J. W. Carr</td><td>https://www.inaturalist.org/observations/59717337</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>17 June 2021</td><td>iNaturalist</td><td>Gray Catanzaro</td><td>https://www.inaturalist.org/observations/100529409</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>September 2022</td><td>iNaturalist</td><td>Dean Firth</td><td>https://www.inaturalist.org/observations/135064425</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>30 August 2023</td><td>iNaturalist</td><td>Bert Harris</td><td>https://www.inaturalist.org/observations/180897649</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>April 2023</td><td>iNaturalist</td><td>Heather</td><td>https://www.inaturalist.org/observations/155028186</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>23 April 2022</td><td>iNaturalist</td><td>Henry</td><td>https://www.inaturalist.org/observations/112557111</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>3 May 2020</td><td>iNaturalist</td><td>Koaw Nature</td><td>https://www.inaturalist.org/observations/44826202</td></tr><tr><td>S. subterraneus</td><td>Virginia</td><td>12 June 2023</td><td>iNaturalist</td><td>Gideon Snavely</td><td>https://www.inaturalist.org/observations/167197041</td></tr><tr><td>Scarites sp.</td><td>Virginia</td><td>14 May 2021</td><td>iNaturalist</td><td>Mark Richman</td><td>https://www.inaturalist.org/observations/78795746</td></tr><tr><td>S. quadriceps or vicinus</td><td>West Virginia</td><td>August 2019</td><td>iNaturalist</td><td>bensect</td><td>https://www.inaturalist.org/observations/31240371</td></tr><tr><td>S. subterraneus</td><td>West Virginia</td><td>18 May 2021</td><td>iNaturalist</td><td>becksnyc</td><td>https://www.inaturalist.org/observations/79429278</td></tr><tr><td>S. subterraneus</td><td>Wisconsin</td><td>20 May 2021</td><td>iNaturalist</td><td>glcarlton</td><td>https://www.inaturalist.org/observations/79589418</td></tr></tbody></table>

Distribution map

Known localities for *Micromegistus bakeri* in North America were compiled from published literature (Trägårdh 1948; Nickel and Elzinga 1970a; McDaniel and Bolen 1979), as well as specimens housed in the OSAL and vouchered in BOLD. Photographs of *S. subterraneus*; *S. lissopterus* Chaudoir; *S. marinus* Nichols; *S. ocalensis* Nichols; *S. quadriceps* Chaudoir; *S. stenops* Bousquet & Skelley; *S. vicinus* Chaudoir; and unidentified *Scarites* posted to iNaturalist
<table><caption>**Table 2** The occurrence of *Micromegistus bakeri* on ground beetles (Carabidae) collected from Stone Valley Recreational Area, Pennsylvania.</caption><thead><tr><th>Host</th><th>No. beetles examined</th><th>No. beetles infested</th><th>% infestation</th><th>Total no. mites collected</th><th>Average no. mites per infested beetle</th><th>Range of no. mites per infested beetle</th></tr></thead><tbody><tr><td>Scarites subterraneus</td><td>37</td><td>10</td><td>27</td><td>31</td><td>3.1</td><td>1–8</td></tr><tr><td>Amara aenea<sup>1</sup></td><td>147</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Harpalus affinis</td><td>142</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Pterostichus diligens</td><td>67</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Carabus goryi</td><td>63</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Agonum spp.<sup>1</sup></td><td>60</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Anisodactylus harrisii</td><td>44</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Harpalus pensylvanicus</td><td>40</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Platynus decentis</td><td>33</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Pterostichus mutus</td><td>21</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Platynus angustatus</td><td>14</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Poecilus lucublandus</td><td>14</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Pterostichus moestus</td><td>14</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Sphaeroderus stenostomus</td><td>13</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Other carabid species<sup>2</sup></td><td>49</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr></tbody></table>

(https://www.inaturalist.org) and BugGuide (https://bugguide.net) were examined for visible mites to document additional suspected locality records (Table 1). The identities of all *Scarites* that had mites were confirmed by the authors. The map was created in Adobe Illustrator using Google Maps to mark localities. Because (1) the range of *S. subterraneus* encompasses the ranges of the other six *Scarites* species found in the United States and Canada, (2) the species identity of many *Scarites* posted on iNaturalist could not be confirmed beyond genus due to the absence of morphologically informative characters in photographs, and (3) *Micromegistus*-like mites were found on *Scarites* species other than *S. subterraneus* (see “Utility of citizen science photographs” below), the range map is based on all Research-grade *Scarites* observations available on iNaturalist.

# Results and discussion

## Field collections and host range

In total, 573 ground beetles, representing 32 species, were collected. *Micromegistus bakeri* were found on 10 of 37 (27%) of *S. subterraneus*, but none of the 31 other carabid species (Table 2). *Micromegistus bakeri* was the only mite species observed on the field-collected ground beetles, although the subelytral space was not examined for mites. Although most carabid taxa were collected in low abundances (17 species plus unidentified *Amara* spp.), we collected at least 10 specimens from each of 13 non-*Scarites* taxa (12 species plus unidentified *Agonum* spp.). Furthermore, six of these species were found in abundances (33–147 individuals) similar to or greater than *S. subterraneus*, suggesting that *M. bakeri* do not use these carabids as hosts despite their similar prevalence in this locality. To our knowledge, Nickel and Elzinga (1970a) conducted the only other assessment of host range in *M. bakeri*, which encompassed a single locality in Kansas. They observed a high prevalence of *M. bakeri* on *S. subterraneus* (52 of 112 specimens; 46.4%). They also observed the mites on two other carabid beetles, *Cyclotrachelus sodalis* LeConte (reported as *Evarthus sodalis colossus* in their study), and *Patrobus longicornis*, that occurred at the same site. Infestation rates on these two carabid species were high (25% and 33% of beetles had mites, respectively), but these figures were based on the inspection of only four and six specimens, respectively. With such limited data on the association between *M. bakeri* and these two apparent hosts, it remains unclear whether these occurrences represent accidental phoresy or a true symbiotic relationship.

<footnote n="1">¹ Some *Amara* spp. (see below) and *Agonum* spp. could not confidently be identified to species.</footnote>

<footnote n="2">² *Chlaenius lithophilus* (7), *Calathus opaculus* (5), *Chlaenius tricolor* (5), *Trichotichnus fulgens* (5), *Nebria lacustris* (4), *Amara* spp.1 (3), *Chlaenius aestivus* (3), *Acupalpus partiarius* (2), *Anisodactylus sanctaeccrucis* (2), *Lachnocrepis parallela* (2), *Harpalus caliginosus* (2), *Badister notatus* (2), *Myas coracinus* (2), *Acupalpus pauperculus* (1), *Amara ovata* (1), *Amphasia interstitialis* (1), *Apenes lucidula* (1), *Dicaelus dilatatus* (1).</footnote>
<table><caption>**Table 2** The occurrence of *Micromegistus bakeri* on ground beetles (Carabidae) collected from Stone Valley Recreational Area, Pennsylvania.</caption><thead><tr><th>Host</th><th>No. beetles examined</th><th>No. beetles infested</th><th>% infestation</th><th>Total no. mites collected</th><th>Average no. mites per infested beetle</th><th>Range of no. mites per infested beetle</th></tr></thead><tbody><tr><td>Scarites subterraneus</td><td>37</td><td>10</td><td>27</td><td>31</td><td>3.1</td><td>1–8</td></tr><tr><td>Amara aenea<sup>1</sup></td><td>147</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Harpalus affinis</td><td>142</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Pterostichus diligens</td><td>67</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Carabus goryi</td><td>63</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Agonum spp.<sup>1</sup></td><td>60</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Anisodactylus harrisii</td><td>44</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Harpalus pensylvanicus</td><td>40</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Platynus decentis</td><td>33</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Pterostichus mutus</td><td>21</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Platynus angustatus</td><td>14</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Poecilus lucublandus</td><td>14</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Pterostichus moestus</td><td>14</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Sphaeroderus stenostomus</td><td>13</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr><tr><td>Other carabid species<sup>2</sup></td><td>49</td><td>0</td><td>0</td><td>0</td><td>0</td><td>0</td></tr></tbody></table>

(https://www.inaturalist.org) and BugGuide (https://bugguide.net) were examined for visible mites to document additional suspected locality records (Table 1). The identities of all *Scarites* that had mites were confirmed by the authors. The map was created in Adobe Illustrator using Google Maps to mark localities. Because (1) the range of *S. subterraneus* encompasses the ranges of the other six *Scarites* species found in the United States and Canada, (2) the species identity of many *Scarites* posted on iNaturalist could not be confirmed beyond genus due to the absence of morphologically informative characters in photographs, and (3) *Micromegistus*-like mites were found on *Scarites* species other than *S. subterraneus* (see “Utility of citizen science photographs” below), the range map is based on all Research-grade *Scarites* observations available on iNaturalist.

# Results and discussion

## Field collections and host range

In total, 573 ground beetles, representing 32 species, were collected. *Micromegistus bakeri* were found on 10 of 37 (27%) of *S. subterraneus*, but none of the 31 other carabid species (Table 2). *Micromegistus bakeri* was the only mite species observed on the field-collected ground beetles, although the subelytral space was not examined for mites. Although most carabid taxa were collected in low abundances (17 species plus unidentified *Amara* spp.), we collected at least 10 specimens from each of 13 non-*Scarites* taxa (12 species plus unidentified *Agonum* spp.). Furthermore, six of these species were found in abundances (33–147 individuals) similar to or greater than *S. subterraneus*, suggesting that *M. bakeri* do not use these carabids as hosts despite their similar prevalence in this locality. To our knowledge, Nickel and Elzinga (1970a) conducted the only other assessment of host range in *M. bakeri*, which encompassed a single locality in Kansas. They observed a high prevalence of *M. bakeri* on *S. subterraneus* (52 of 112 specimens; 46.4%). They also observed the mites on two other carabid beetles, *Cyclotrachelus sodalis* LeConte (reported as *Evarthus sodalis colossus* in their study), and *Patrobus longicornis*, that occurred at the same site. Infestation rates on these two carabid species were high (25% and 33% of beetles had mites, respectively), but these figures were based on the inspection of only four and six specimens, respectively. With such limited data on the association between *M. bakeri* and these two apparent hosts, it remains unclear whether these occurrences represent accidental phoresy or a true symbiotic relationship.

<footnote n="1">¹ Some *Amara* spp. (see below) and *Agonum* spp. could not confidently be identified to species.</footnote>

<footnote n="2">² *Chlaenius lithophilus* (7), *Calathus opaculus* (5), *Chlaenius tricolor* (5), *Trichotichnus fulgens* (5), *Nebria lacustris* (4), *Amara* spp.1 (3), *Chlaenius aestivus* (3), *Acupalpus partiarius* (2), *Anisodactylus sanctaeccrucis* (2), *Lachnocrepis parallela* (2), *Harpalus caliginosus* (2), *Badister notatus* (2), *Myas coracinus* (2), *Acupalpus pauperculus* (1), *Amara ovata* (1), *Amphasia interstitialis* (1), *Apenes lucidula* (1), *Dicaelus dilatatus* (1).</footnote>
Nickel and Elzinga (1970a) did not indicate whether they surveyed other carabid species to test the host range of *M. bakeri*. However, their data are part of a larger dataset of mites collected from a total of 18 carabid species in the frame of Nickel's thesis (Nickel 1969), from which results on other mite species were published (Nickel and Elzinga 1969, 1970b). Those publications indicate the absence of *M. bakeri* from the other 15 carabid species studies. Other than *S. subterraneus*, five carabid species had more than 10 individuals collected and four had more than 100 individuals collected – none of which carried *M. bakeri*. This, and two additional elements, further support a strong host preference for *Scarites* or specifically *S. subterraneus* over other potential carabid hosts. Firstly, from 44 records of *M. bakeri* in other states (Table 3), 42 (95%) had *Scarites* identified as host, including 5 (11.3%) identified specifically as *S. subterraneus*. Secondly, based on male morphology, *M. bakeri* is most closely related to *M. viduus*, which occurs on *Scarites* sp. in South America (Berlese 1988, Kim and Castagnoli 2010).

## New state records

The specimens from Pennsylvania represent a new state record. Sixty-three specimens are housed in the OSAL collection, of which 42 include locality data (Table 3) and represent new state records for Ohio, Michigan, Missouri, and new country and province records for Ontario, Canada (Figure 3). The specimen discovered through BOLD (see *DNA results* below) represents a new state record for Arizona.

## Preference for the beetle's ventral surface

*Micromegistus bakeri* favor the ventral surface of their hosts (Figures 1–2) and can remain somewhat hidden under the prothorax and beneath or around the legs. Nickel and Elzinga (1970a) found that the mites prefer the coxeae, trochanters and femora of legs II, and will secondarily occupy the same segments of legs I and III, as well as the thorax near the narrow junction between the prothorax and mesothorax of the beetle. Our inspection of two *S. subterraneus* infested with *M. bakeri* revealed that the mites favored the area around the junction of the prothorax and mesothorax (Figure 1b) compared to the other regions of the beetle noted by Nickel and Elzinga (1970a). However, as the mite population grew on these two *S. subterraneus* kept in the lab, increased activity on the entire ventral surface was also noted, presumably because preferred sites were overcrowded. Immatures were often observed interacting with adult mites (Figure 1c shows a larva on an adult, probably a female), and were frequently found on the beetle's mandibles as well as occasionally walking across the elytra.

## Utility of citizen science photographs

Photographs on BugGuide and iNaturalist of 6,692 individual *Scarites* were screened for mites. Of those, 122 beetles (1.82%) hosted *Micromegistus*-like mites (Table 1, Figure 2). Although

<table><caption>**Table 3** *Micromegistus bakeri* specimens housed in the Ohio State University Acarology Collection. Life stages are abbreviated as follows: F – female, M – male, DN – deutonymph, N – nymph (protonymph or deutonymph not specified), L – larva, U – unknown (unspecified) life stage, ? – host or locality unknown.</caption><thead><tr><th>Country</th><th>State/Province</th><th>County</th><th>Number of specimens</th><th>Life stages</th><th>Host</th></tr></thead><tbody><tr><td>Canada</td><td>Ontario</td><td>Essex</td><td>1</td><td>1 F</td><td>?</td></tr><tr><td>United States</td><td>Kansas</td><td>Douglas</td><td>4</td><td>1 F, 2 M, 1 N</td><td>Scarites sp.</td></tr><tr><td>United States</td><td>Michigan</td><td>Wayne</td><td>14</td><td>8 F, 4 M, 1 DN, 1 PN</td><td>Scarites sp.</td></tr><tr><td>United States</td><td>Missouri</td><td>Boone</td><td>1</td><td>1 F</td><td>Scarites sp.</td></tr><tr><td>United States</td><td>Ohio</td><td>Franklin</td><td>11</td><td>3 F, 1 L, 7 U</td><td>Scarites sp.</td></tr><tr><td>United States</td><td>Ohio</td><td>Franklin</td><td>6</td><td>1 F, 1 M, 4 DN</td><td>Scarites subterraneus</td></tr><tr><td>United States</td><td>Ohio</td><td>Franklin</td><td>1</td><td>1 DN</td><td>?</td></tr><tr><td>?</td><td>?</td><td>?</td><td>7</td><td>5 F, 1 M, 1 PN</td><td>Scarites sp.</td></tr><tr><td>Total specimens</td><td></td><td></td><td>45</td><td>20 F, 8 M, 6 DN, 2 PN, 1 N, 1 L, 7 U</td><td></td></tr></tbody></table>
Nickel and Elzinga (1970a) did not indicate whether they surveyed other carabid species to test the host range of *M. bakeri*. However, their data are part of a larger dataset of mites collected from a total of 18 carabid species in the frame of Nickel's thesis (Nickel 1969), from which results on other mite species were published (Nickel and Elzinga 1969, 1970b). Those publications indicate the absence of *M. bakeri* from the other 15 carabid species studies. Other than *S. subterraneus*, five carabid species had more than 10 individuals collected and four had more than 100 individuals collected – none of which carried *M. bakeri*. This, and two additional elements, further support a strong host preference for *Scarites* or specifically *S. subterraneus* over other potential carabid hosts. Firstly, from 44 records of *M. bakeri* in other states (Table 3), 42 (95%) had *Scarites* identified as host, including 5 (11.3%) identified specifically as *S. subterraneus*. Secondly, based on male morphology, *M. bakeri* is most closely related to *M. viduus*, which occurs on *Scarites* sp. in South America (Berlese 1988, Kim and Castagnoli 2010).

## New state records

The specimens from Pennsylvania represent a new state record. Sixty-three specimens are housed in the OSAL collection, of which 42 include locality data (Table 3) and represent new state records for Ohio, Michigan, Missouri, and new country and province records for Ontario, Canada (Figure 3). The specimen discovered through BOLD (see *DNA results* below) represents a new state record for Arizona.

## Preference for the beetle's ventral surface

*Micromegistus bakeri* favor the ventral surface of their hosts (Figures 1–2) and can remain somewhat hidden under the prothorax and beneath or around the legs. Nickel and Elzinga (1970a) found that the mites prefer the coxeae, trochanters and femora of legs II, and will secondarily occupy the same segments of legs I and III, as well as the thorax near the narrow junction between the prothorax and mesothorax of the beetle. Our inspection of two *S. subterraneus* infested with *M. bakeri* revealed that the mites favored the area around the junction of the prothorax and mesothorax (Figure 1b) compared to the other regions of the beetle noted by Nickel and Elzinga (1970a). However, as the mite population grew on these two *S. subterraneus* kept in the lab, increased activity on the entire ventral surface was also noted, presumably because preferred sites were overcrowded. Immatures were often observed interacting with adult mites (Figure 1c shows a larva on an adult, probably a female), and were frequently found on the beetle's mandibles as well as occasionally walking across the elytra.

## Utility of citizen science photographs

Photographs on BugGuide and iNaturalist of 6,692 individual *Scarites* were screened for mites. Of those, 122 beetles (1.82%) hosted *Micromegistus*-like mites (Table 1, Figure 2). Although

<table><caption>**Table 3** *Micromegistus bakeri* specimens housed in the Ohio State University Acarology Collection. Life stages are abbreviated as follows: F – female, M – male, DN – deutonymph, N – nymph (protonymph or deutonymph not specified), L – larva, U – unknown (unspecified) life stage, ? – host or locality unknown.</caption><thead><tr><th>Country</th><th>State/Province</th><th>County</th><th>Number of specimens</th><th>Life stages</th><th>Host</th></tr></thead><tbody><tr><td>Canada</td><td>Ontario</td><td>Essex</td><td>1</td><td>1 F</td><td>?</td></tr><tr><td>United States</td><td>Kansas</td><td>Douglas</td><td>4</td><td>1 F, 2 M, 1 N</td><td>Scarites sp.</td></tr><tr><td>United States</td><td>Michigan</td><td>Wayne</td><td>14</td><td>8 F, 4 M, 1 DN, 1 PN</td><td>Scarites sp.</td></tr><tr><td>United States</td><td>Missouri</td><td>Boone</td><td>1</td><td>1 F</td><td>Scarites sp.</td></tr><tr><td>United States</td><td>Ohio</td><td>Franklin</td><td>11</td><td>3 F, 1 L, 7 U</td><td>Scarites sp.</td></tr><tr><td>United States</td><td>Ohio</td><td>Franklin</td><td>6</td><td>1 F, 1 M, 4 DN</td><td>Scarites subterraneus</td></tr><tr><td>United States</td><td>Ohio</td><td>Franklin</td><td>1</td><td>1 DN</td><td>?</td></tr><tr><td>?</td><td>?</td><td>?</td><td>7</td><td>5 F, 1 M, 1 PN</td><td>Scarites sp.</td></tr><tr><td>Total specimens</td><td></td><td></td><td>45</td><td>20 F, 8 M, 6 DN, 2 PN, 1 N, 1 L, 7 U</td><td></td></tr></tbody></table>
<figure><img src="image_3.png" /><figcaption>**Figure 1** *Micromegistus bakeri* on *Scarites subterraneus*. a – Dorsal and ventral view of infested *S. subterraneus*. b – The anterior ventral side of *M. bakeri* infested *S. subterraneus*. c – Adult and larval *M. bakeri*.</figcaption></figure>

these mites had the correct gestalt for *M. bakeri*, we cannot confirm the species identity of the mites from the photographs alone. We therefore report them here as “suspected” *M. bakeri* records that require confirmation through examination of physical specimens but do not include them in the new state records listed above.

A majority of the mites (73/122; 59.8%) found in citizen science photographs were on *S. subterraneus*, which is part of the *S. subterraneus* species group. The three other North American species of this group – *S. marinus*, *S. ocalensis*, and *S. stenops* – have restricted ranges in Florida and Louisiana so are rarely encountered or photographed. A few mites (12/122; 9.8%) were found on beetles of the *S. quadriceps* species group, which comprises three species: *S. quadriceps*, *S. vicinus* and *S. lissopterus*. *Scarites quadriceps* occurs from
<figure><img src="image_4.png" /><figcaption>**Figure 1** *Micromegistus bakeri* on *Scarites subterraneus*. a – Dorsal and ventral view of infested *S. subterraneus*. b – The anterior ventral side of *M. bakeri* infested *S. subterraneus*. c – Adult and larval *M. bakeri*.</figcaption></figure>

these mites had the correct gestalt for *M. bakeri*, we cannot confirm the species identity of the mites from the photographs alone. We therefore report them here as “suspected” *M. bakeri* records that require confirmation through examination of physical specimens but do not include them in the new state records listed above.

A majority of the mites (73/122; 59.8%) found in citizen science photographs were on *S. subterraneus*, which is part of the *S. subterraneus* species group. The three other North American species of this group – *S. marinus*, *S. ocalensis*, and *S. stenops* – have restricted ranges in Florida and Louisiana so are rarely encountered or photographed. A few mites (12/122; 9.8%) were found on beetles of the *S. quadriceps* species group, which comprises three species: *S. quadriceps*, *S. vicinus* and *S. lissopterus*. *Scarites quadriceps* occurs from
<figure><img src="image_4.png" /><figcaption>**Figure 2** Examples of photographic records of mites (putatively identified as *M. bakeri*) on *Scarites* spp., available on the citizen science websites BugGuide and iNaturalist. Note how only one or no mites are visible in the dorsal images, while one to many are visible in the lateral and ventral images. 2a – by lazarus via iNaturalist, used under a CC BY 4.0 license. 2b–2c by Bert Harris and Breanna Couey, respectively, via iNaturalist, used under CC BY-NC 4.0 licenses.</figcaption></figure>

Maryland and Florida west to Texas. *Scarites vicinus* occurs from Ontario and Alabama west to Iowa and Texas, so has a somewhat more northern range compared to *S. vicinus* but they co-occur across much of the eastern United States. *Scarites lissopterus* occurs Louisiana and Kansas west to New Mexico. All three species co-occur in Louisiana, Kansas, and Texas. They are distinguished based on the length of the metasternum compared to the length of the metacoxa and differences in absolute body length, which are often difficult to see or determine from photographs; so, in most cases we could not confirm the identification of beetles beyond the *S. quadriceps* species group in areas where they co-occur. The remaining mites (37/122; 30.3%) were on *Scarites* whose species identification could not be confirmed beyond genus
<figure><img src="image_5.png" /><figcaption>**Figure 2** Examples of photographic records of mites (putatively identified as *M. bakeri*) on *Scarites* spp., available on the citizen science websites BugGuide and iNaturalist. Note how only one or no mites are visible in the dorsal images, while one to many are visible in the lateral and ventral images. 2a – by lazarus via iNaturalist, used under a CC BY 4.0 license. 2b–2c by Bert Harris and Breanna Couey, respectively, via iNaturalist, used under CC BY-NC 4.0 licenses.</figcaption></figure>

Maryland and Florida west to Texas. *Scarites vicinus* occurs from Ontario and Alabama west to Iowa and Texas, so has a somewhat more northern range compared to *S. vicinus* but they co-occur across much of the eastern United States. *Scarites lissopterus* occurs Louisiana and Kansas west to New Mexico. All three species co-occur in Louisiana, Kansas, and Texas. They are distinguished based on the length of the metasternum compared to the length of the metacoxa and differences in absolute body length, which are often difficult to see or determine from photographs; so, in most cases we could not confirm the identification of beetles beyond the *S. quadriceps* species group in areas where they co-occur. The remaining mites (37/122; 30.3%) were on *Scarites* whose species identification could not be confirmed beyond genus
due to the lack of morphologically informative characters in the photographs.

Presuming the mites seen in citizen science photographs are indeed *M. bakeri*, their prevalence on *Scarites* spp. appears to be much lower than has been reported in previous studies (Nickel and Elzinga 1970a: 46.4%) and in this study (27%). This is likely due to the relatively poor quality of many photographs on iNaturalist and BugGuide and the mites' tendency to favor the beetles' venter, which is often hidden from view in photographs and impeded our ability to detect more *S. subterraneus* specimens harboring mites in these databases. It could also be that photographers avoided specimens with obvious mites or removed mites prior to photographing them, either intentionally for more visually compelling photographs or unintentionally by handling the beetles prior to photographing them, although we suspect that this happens infrequent enough that it is not the sole cause of the discrepancy. Alternatively, many *S. subterraneus* records on citizen science websites originated from urban areas, and lower mite infestation rates on other ground beetle species have been reported from urban compared to rural forest sites (e.g., Mizser 2016), so the discrepancy may reflect a real ecological trend, at least partially.

In addition to *Micromegistus*, we also detected other mites on photographed *Scarites*, although at much lower rates (Table 4). Four records consist of mesostigmatans that cannot be identified to family with confidence, and one represents a species of Astigmata, possibly of the family Histiostomatidae. One of the records (Minnesota) appears to represent at least two species of Mesostigmata, one of which, the most numerous, could be deutonymphs of the family Parasitidae. Their high numbers clearly indicate that it's not accidental phoresy.

The small size and the inherently limited public interest in mites restrict the use of crowd-sourced photographic data in acarology, which is highlighted by our inability to identify non-*Micromegistus* mites in photographs. Indeed, the only publication using citizen science photographs to study mesostigmatic mites compared the diversity of field-collected arthropods to citizen science photographs from the same region and reported an *absence* of mesostigmatic mite in the photographs (Dolezal 2019, Skvarla and Fisher 2023). This study, by comparison, is the first to use *presence* data to study mesostigmatic mites and demonstrates that citizen science photographs can provide a useful resource when certain criteria are met. In this case, the hosts are commonly photographed, so even a low detection rate of 1.8% produced more than 100 putative records of *M. bakeri*, and the mites have a fairly unique gestalt (e.g. idiosoma almost as wide as long and ovate, i.e. broader posteriorly, legs spread laterally and front legs antennae-like) that distinguish them from other *Scarites*-inhabiting mites, and from most other mites known in North America. While there are potential pitfalls associated with citizen science data such as their limited reliability for species identification and the impermanence of such data (see Skvarla and Fisher (2023) for a detailed discussion of this), it can provide additional data that would otherwise be unavailable, as shown by our expanded distribution map (Figure 3).

<table><caption>**Table 4** Publicly available records on BugGuide and iNaturalist that show *Scarites* with mites other than *Micromegistus bakeri*. All photographs were accessed from 24 March – 1 April 2024.</caption><thead><tr><th>Beetle taxon</th><th>Mite taxon</th><th>Notes</th><th>State/Province</th><th>Date photographed</th><th>Website</th><th>Photographer</th><th>URL</th></tr></thead><tbody><tr><td>Scarites sp.</td><td>Mesostigmata</td><td>1 adult mite on elytron</td><td>Ontario</td><td>14 August 2023</td><td>iNaturalist</td><td>Rowan<br>Koropatniski</td><td>https://www.inaturalist.org/observation<br>s/178421081</td></tr><tr><td>S. subterraneus</td><td>Mesostigmata</td><td>2 mites, one each on pronotum and elytron</td><td>Virginia</td><td>10 August 2023</td><td>iNaturalist</td><td>Mark Richman</td><td>https://www.inaturalist.org/observation<br>s/177932003</td></tr><tr><td>S. subterraneus</td><td>Mesostigmata: 2 or more spp. of Gamasina</td><td>&gt;80 mites, mostly on femora, prosternum and mouthparts</td><td>Minnesota</td><td>17 June 2022</td><td>iNaturalist</td><td>Krista Menzel</td><td>https://www.inaturalist.org/observation<br>s/167648754</td></tr><tr><td>S. subterraneus</td><td>Astigmata</td><td>Several deutonymphs on 2<sup>nd</sup> femora, and between pronotum and elytra</td><td>Pennsylvania</td><td>20 May 2022</td><td>iNaturalist</td><td>Natalie Waddell-Rutter</td><td>https://www.inaturalist.org/observation<br>s/119532499</td></tr><tr><td>Scarites sp.</td><td>Mesostigmata: Gamasina</td><td>1 adult mite on pronotum</td><td>Texas</td><td>26 March 2021</td><td>BugGuide</td><td>Stuart J. Marcus</td><td>https://bugguide.net/node/view/195129<br>4/bgimage</td></tr></tbody></table>
due to the lack of morphologically informative characters in the photographs.

Presuming the mites seen in citizen science photographs are indeed *M. bakeri*, their prevalence on *Scarites* spp. appears to be much lower than has been reported in previous studies (Nickel and Elzinga 1970a: 46.4%) and in this study (27%). This is likely due to the relatively poor quality of many photographs on iNaturalist and BugGuide and the mites' tendency to favor the beetles' venter, which is often hidden from view in photographs and impeded our ability to detect more *S. subterraneus* specimens harboring mites in these databases. It could also be that photographers avoided specimens with obvious mites or removed mites prior to photographing them, either intentionally for more visually compelling photographs or unintentionally by handling the beetles prior to photographing them, although we suspect that this happens infrequent enough that it is not the sole cause of the discrepancy. Alternatively, many *S. subterraneus* records on citizen science websites originated from urban areas, and lower mite infestation rates on other ground beetle species have been reported from urban compared to rural forest sites (e.g., Mizser 2016), so the discrepancy may reflect a real ecological trend, at least partially.

In addition to *Micromegistus*, we also detected other mites on photographed *Scarites*, although at much lower rates (Table 4). Four records consist of mesostigmatans that cannot be identified to family with confidence, and one represents a species of Astigmata, possibly of the family Histiostomatidae. One of the records (Minnesota) appears to represent at least two species of Mesostigmata, one of which, the most numerous, could be deutonymphs of the family Parasitidae. Their high numbers clearly indicate that it's not accidental phoresy.

The small size and the inherently limited public interest in mites restrict the use of crowd-sourced photographic data in acarology, which is highlighted by our inability to identify non-*Micromegistus* mites in photographs. Indeed, the only publication using citizen science photographs to study mesostigmatic mites compared the diversity of field-collected arthropods to citizen science photographs from the same region and reported an *absence* of mesostigmatic mite in the photographs (Dolezal 2019, Skvarla and Fisher 2023). This study, by comparison, is the first to use *presence* data to study mesostigmatic mites and demonstrates that citizen science photographs can provide a useful resource when certain criteria are met. In this case, the hosts are commonly photographed, so even a low detection rate of 1.8% produced more than 100 putative records of *M. bakeri*, and the mites have a fairly unique gestalt (e.g. idiosoma almost as wide as long and ovate, i.e. broader posteriorly, legs spread laterally and front legs antennae-like) that distinguish them from other *Scarites*-inhabiting mites, and from most other mites known in North America. While there are potential pitfalls associated with citizen science data such as their limited reliability for species identification and the impermanence of such data (see Skvarla and Fisher (2023) for a detailed discussion of this), it can provide additional data that would otherwise be unavailable, as shown by our expanded distribution map (Figure 3).

<table><caption>**Table 4** Publicly available records on BugGuide and iNaturalist that show *Scarites* with mites other than *Micromegistus bakeri*. All photographs were accessed from 24 March – 1 April 2024.</caption><thead><tr><th>Beetle taxon</th><th>Mite taxon</th><th>Notes</th><th>State/Province</th><th>Date photographed</th><th>Website</th><th>Photographer</th><th>URL</th></tr></thead><tbody><tr><td>Scarites sp.</td><td>Mesostigmata</td><td>1 adult mite on elytron</td><td>Ontario</td><td>14 August 2023</td><td>iNaturalist</td><td>Rowan<br>Koropatniski</td><td>https://www.inaturalist.org/observation<br>s/178421081</td></tr><tr><td>S. subterraneus</td><td>Mesostigmata</td><td>2 mites, one each on pronotum and elytron</td><td>Virginia</td><td>10 August 2023</td><td>iNaturalist</td><td>Mark Richman</td><td>https://www.inaturalist.org/observation<br>s/177932003</td></tr><tr><td>S. subterraneus</td><td>Mesostigmata: 2 or more spp. of Gamasina</td><td>>80 mites, mostly on femora, prosternum and mouthparts</td><td>Minnesota</td><td>17 June 2022</td><td>iNaturalist</td><td>Krista Menzel</td><td>https://www.inaturalist.org/observation<br>s/167648754</td></tr><tr><td>S. subterraneus</td><td>Astigmata</td><td>Several deutonymphs on 2<sup>nd</sup> femora, and between pronotum and elytra</td><td>Pennsylvania</td><td>20 May 2022</td><td>iNaturalist</td><td>Natalie Waddell-Rutter</td><td>https://www.inaturalist.org/observation<br>s/119532499</td></tr><tr><td>Scarites sp.</td><td>Mesostigmata: Gamasina</td><td>1 adult mite on pronotum</td><td>Texas</td><td>26 March 2021</td><td>BugGuide</td><td>Stuart J. Marcus</td><td>https://bugguide.net/node/view/195129<br>4/bgimage</td></tr></tbody></table>
<figure><img src="image_5.png" /></figure>

**Figure 3** Distribution map of *Micromegistus bakeri* and *Scarites* spp. in North America. The star indicates the location of the specimens collected in the present study. Squares indicate localities of *M. bakeri* documented in the literature (Trägårdh 1948; Nickel and Elzinga 1970; McDaniel and Bolen 1979) as well as records from the Ohio State University Acarology Collection and the Barcode of Life Datasystem (see Table 2). Citizen science records of mites suspected to be *M. bakeri* are shown by host: red circles for *S. subterraneus*, magenta circles for all *S. quadriceps* species group individuals (including those identified to species, i.e., a single *S. lissopterus* specimen in Texas), and yellow circles for beetles that could not be identified past genus. The range for *Scarites* spp. was based on all research-grade iNaturalist observations of *Scarites* in the United States and Canada, which were confirmed by the authors.

## DNA results

This study presents the first COI DNA barcode record for *Micromegistus bakeri* available in any public sequence repository, representing a 658 bp (32.5% GC) sequence lacking any ambiguous bases. In BOLD, there were six COI sequences representing potentially two other species of Parantennulidae. The nearest neighbor (6.6% p-distance) of this sequence on BOLD [Accessed May 17th, 2022] belonged to a previously unidentified Parantennulidae specimen (Sample ID = DPMIT-41-72) collected from Deadhorse Ranch State Park in Arizona, United States; we borrowed the specimen (from the Centre for Biodiversity Genomics) and identified it as *M. bakeri* based on the absence of any significant morphological differences with our specimen from Pennsylvania and on comparisons with published descriptions of *M. bakeri*. This finding indicates a relatively high intraspecific divergence in *M. bakeri*, which exceeds the typical divergence values for mesostigmatic mites (Li *et al.* 2012; Young *et al.* 2019). This high divergence may be in part due to the geographic distance between the specimens (~3,050 km), but without additional specimens it is unclear if these represent genetically divergent specimens on the edges of the species range or rather cryptic species that we cannot yet distinguish. The other parantennulid species represented on BOLD is *M. gourlayi*, which originated from four GenBank records (EU825790-EU825793) collected in New Zealand; it was at least 19.3% divergent (p-distance) from our new record of *M. bakeri*.

## Micromegistus bakeri feeding behavior and relationship with the host

*Scarites subterraneus* are morphologically convergent with passalid beetles, sharing with them a large robust body, a stalked prothorax, strong mandibles, and a burrowing behavior. The species burrows under logs, rocks or litter, where it hides during the day, mostly motionless, and hunts at night, bringing their prey underground before feeding (Hlavac 1967; Larochelle and Larivière 2003). It occurs in anthropogenic and open natural habitats, such as lawns, pastures,
<figure><img src="image_6.png" /></figure>

**Figure 3** Distribution map of *Micromegistus bakeri* and *Scarites* spp. in North America. The star indicates the location of the specimens collected in the present study. Squares indicate localities of *M. bakeri* documented in the literature (Trägårdh 1948; Nickel and Elzinga 1970; McDaniel and Bolen 1979) as well as records from the Ohio State University Acarology Collection and the Barcode of Life Datasystem (see Table 2). Citizen science records of mites suspected to be *M. bakeri* are shown by host: red circles for *S. subterraneus*, magenta circles for all *S. quadriceps* species group individuals (including those identified to species, i.e., a single *S. lissopterus* specimen in Texas), and yellow circles for beetles that could not be identified past genus. The range for *Scarites* spp. was based on all research-grade iNaturalist observations of *Scarites* in the United States and Canada, which were confirmed by the authors.

## DNA results

This study presents the first COI DNA barcode record for *Micromegistus bakeri* available in any public sequence repository, representing a 658 bp (32.5% GC) sequence lacking any ambiguous bases. In BOLD, there were six COI sequences representing potentially two other species of Parantennulidae. The nearest neighbor (6.6% p-distance) of this sequence on BOLD [Accessed May 17th, 2022] belonged to a previously unidentified Parantennulidae specimen (Sample ID = DPMIT-41-72) collected from Deadhorse Ranch State Park in Arizona, United States; we borrowed the specimen (from the Centre for Biodiversity Genomics) and identified it as *M. bakeri* based on the absence of any significant morphological differences with our specimen from Pennsylvania and on comparisons with published descriptions of *M. bakeri*. This finding indicates a relatively high intraspecific divergence in *M. bakeri*, which exceeds the typical divergence values for mesostigmatic mites (Li *et al.* 2012; Young *et al.* 2019). This high divergence may be in part due to the geographic distance between the specimens (~3,050 km), but without additional specimens it is unclear if these represent genetically divergent specimens on the edges of the species range or rather cryptic species that we cannot yet distinguish. The other parantennulid species represented on BOLD is *M. gourlayi*, which originated from four GenBank records (EU825790-EU825793) collected in New Zealand; it was at least 19.3% divergent (p-distance) from our new record of *M. bakeri*.

## Micromegistus bakeri feeding behavior and relationship with the host

*Scarites subterraneus* are morphologically convergent with passalid beetles, sharing with them a large robust body, a stalked prothorax, strong mandibles, and a burrowing behavior. The species burrows under logs, rocks or litter, where it hides during the day, mostly motionless, and hunts at night, bringing their prey underground before feeding (Hlavac 1967; Larochelle and Larivière 2003). It occurs in anthropogenic and open natural habitats, such as lawns, pastures,
open forests, and near water bodies. Their burrows can be as deep as 15 cm (Larochelle and Larivière 2003). Larvae live in the adult's burrows, but also leave the burrows at night for hunting. It overwinters as adults in burrows (Hlavac 1967).

Nickel and Elzinga's (1970a) study showed that *Micromegistus bakeri* essentially completes its entire life cycle on *S. subterraneus*. Female mites carry two large eggs within the opisthosoma which develop concurrently and are born viviparously as larvae. In laboratory conditions, it takes about two weeks before two other larvae are born. Nickel and Elzinga (1970a) observed the birth of a larva, and stated that after emergence, the larva clung onto its mother's venter for a few minutes, and then to its dorsum for a similar period of time. Finally, the larva "descended to the beetle and wandered about for several minutes on the carabid's venter before settling near the junction of trochanter and femur II". This indicates that larvae are born while the adult female is on the host. As much as 30% of all *M. bakeri* collected from *S. subterraneus* by Nickel and Elzinga (1970a) being larvae further supports that. Our own observations (Fig. 1) and museum data (Table 3) are compatible with this.

The relationship between *M. bakeri* and *S. subterraneus* is unclear. Published observations suggest that *M. bakeri* is an opportunistic scavenger, a kleptoparasite, and possibly also a 'paraphage' that feeds on the host's dermal secretions; it was also proposed to be a commensal (Nickel and Elzinga 1971a). The overall net impact on their host, whether detrimental (antagonistic), neutral (commensal), or even beneficial (mutualistic), is unknown. The impact may even shift when various parameters, such as mite density on a host, change. The relationship between *M. bakeri* and *S. subterraneus* may represent a context-dependent commensalism, as recorded in other systems, including density-dependent changes from commensalism to antagonism and commensalism to mutualism (Mathis and Bronstein 2020). In the *S. subterraneus-M. bakeri* system, mites have been observed feeding on the remains of host-killed prey (a mealworm) near the host beetle, feeding on food particles near the beetle's mouth, feeding on debris on the surface of the beetle (Nickel and Elzinga 1970a), and even lapping up beetle regurgitation fluid off the host (Johnston et al. 1947). Due to the size difference between the mites and their hosts, a few mites may not steal enough nutrients from a beetle to have negative effects (i.e., they are commensals), but may negatively impact host nutrient uptake (i.e., they are antagonists) when populations are higher. Nickel and Elzinga (1970a) observed that the mites were "in constant motion, with their chelicerae making lateral, wiping movements" across the body of the beetle and performed a preliminary experiment where radioactive sodium acetate was injected into the beetles to test if *M. bakeri* would assimilate the sodium acetate and thereby indicate that the mite was feeding on the host's secretions. Their results were positive but inconclusive since the radioactive substance could have been absorbed without actual feeding on the host's secretions. This purported feeding on the host's secretions may have no effect on the host, be negative if it forces the host to expend energy replacing the excretions, or perhaps even beneficial if the mites are removing fungal spores or harmful bacteria. Finally, *M. bakeri* eliminates its waste onto the host (Nickel and Elzinga 1970a). During heavy mite infestations the waste accumulates as a soft mass on the anterior portion of the beetle's mesosternum and between coxae II. If this accumulation encourages detrimental microbe growth, it could negatively impact the beetle. In short, there are many potential impacts on the beetles that may vary with mite population size, so further experiments should be conducted to determine what, if any, impact the mites have on their hosts.

The mites appear to occasionally disembark their host, presumably for seeking food, and are sometimes brushed off by the beetle. Mites have been observed remounting their host, and the adults can even jump back onto the host by leaping a distance sometimes greater than four times their body length (Nickel and Elzinga 1970a). This suggests that *M. bakeri* is adapted to wander off the host, probably during the day when the host rests in its burrows. The mite could then scavenge on invertebrate remains left by its host in its burrow or possibly even prey on invertebrates inhabiting the burrows, such as nematodes, although such facultative predatory behavior has not been observed yet. A strange blattisociid mite, *Krantzoseius walteri* Seeman
open forests, and near water bodies. Their burrows can be as deep as 15 cm (Larochelle and Larivière 2003). Larvae live in the adult's burrows, but also leave the burrows at night for hunting. It overwinters as adults in burrows (Hlavac 1967).

Nickel and Elzinga's (1970a) study showed that *Micromegistus bakeri* essentially completes its entire life cycle on *S. subterraneus*. Female mites carry two large eggs within the opisthosoma which develop concurrently and are born viviparously as larvae. In laboratory conditions, it takes about two weeks before two other larvae are born. Nickel and Elzinga (1970a) observed the birth of a larva, and stated that after emergence, the larva clung onto its mother's venter for a few minutes, and then to its dorsum for a similar period of time. Finally, the larva "descended to the beetle and wandered about for several minutes on the carabid's venter before settling near the junction of trochanter and femur II". This indicates that larvae are born while the adult female is on the host. As much as 30% of all *M. bakeri* collected from *S. subterraneus* by Nickel and Elzinga (1970a) being larvae further supports that. Our own observations (Fig. 1) and museum data (Table 3) are compatible with this.

The relationship between *M. bakeri* and *S. subterraneus* is unclear. Published observations suggest that *M. bakeri* is an opportunistic scavenger, a kleptoparasite, and possibly also a 'paraphage' that feeds on the host's dermal secretions; it was also proposed to be a commensal (Nickel and Elzinga 1971a). The overall net impact on their host, whether detrimental (antagonistic), neutral (commensal), or even beneficial (mutualistic), is unknown. The impact may even shift when various parameters, such as mite density on a host, change. The relationship between *M. bakeri* and *S. subterraneus* may represent a context-dependent commensalism, as recorded in other systems, including density-dependent changes from commensalism to antagonism and commensalism to mutualism (Mathis and Bronstein 2020). In the *S. subterraneus-M. bakeri* system, mites have been observed feeding on the remains of host-killed prey (a mealworm) near the host beetle, feeding on food particles near the beetle's mouth, feeding on debris on the surface of the beetle (Nickel and Elzinga 1970a), and even lapping up beetle regurgitation fluid off the host (Johnston et al. 1947). Due to the size difference between the mites and their hosts, a few mites may not steal enough nutrients from a beetle to have negative effects (i.e., they are commensals), but may negatively impact host nutrient uptake (i.e., they are antagonists) when populations are higher. Nickel and Elzinga (1970a) observed that the mites were "in constant motion, with their chelicerae making lateral, wiping movements" across the body of the beetle and performed a preliminary experiment where radioactive sodium acetate was injected into the beetles to test if *M. bakeri* would assimilate the sodium acetate and thereby indicate that the mite was feeding on the host's secretions. Their results were positive but inconclusive since the radioactive substance could have been absorbed without actual feeding on the host's secretions. This purported feeding on the host's secretions may have no effect on the host, be negative if it forces the host to expend energy replacing the excretions, or perhaps even beneficial if the mites are removing fungal spores or harmful bacteria. Finally, *M. bakeri* eliminates its waste onto the host (Nickel and Elzinga 1970a). During heavy mite infestations the waste accumulates as a soft mass on the anterior portion of the beetle's mesosternum and between coxae II. If this accumulation encourages detrimental microbe growth, it could negatively impact the beetle. In short, there are many potential impacts on the beetles that may vary with mite population size, so further experiments should be conducted to determine what, if any, impact the mites have on their hosts.

The mites appear to occasionally disembark their host, presumably for seeking food, and are sometimes brushed off by the beetle. Mites have been observed remounting their host, and the adults can even jump back onto the host by leaping a distance sometimes greater than four times their body length (Nickel and Elzinga 1970a). This suggests that *M. bakeri* is adapted to wander off the host, probably during the day when the host rests in its burrows. The mite could then scavenge on invertebrate remains left by its host in its burrow or possibly even prey on invertebrates inhabiting the burrows, such as nematodes, although such facultative predatory behavior has not been observed yet. A strange blattisociid mite, *Krantzoseius walteri* Seeman
(2012), recently described in Australia may have a somewhat analogous lifestyle to *M. bakeri*. Like *M. bakeri*, all life stages of *K. walteri* appear to live on the host, *Trichosternus perater* (Pterostichini), a burrowing carabid unrelated to *Scarites* spp. Like *S. subterraneus*, *T. perater* brings captured prey into its burrow, where *K. walteri* possibly feeds on microfauna associated with the prey items, such as nematodes, but may also scavenge the rotting prey itself (Seeman 2012; O. Seeman pers. comm. 2024).

Phoretic histiostomatid deutonymphs, which are occasionally found sharing the same host as *M. bakeri*, were not attacked by *M. bakeri* when both were found on the same host (Nickel and Elzinga 1970a, Nickel 1969, Riggins 2023). Indeed, the weakly, nearly edentate chelicerae of *M. bakeri*, with their mop-like appendages, do not appear optimal for seizing active prey, but rather for mopping up fluids, such as those oozing out of dead invertebrates, a behavior seen in other Trigynaspida (Seeman 2000). The larvae, nymphs and adult females and males all having similar chelicerae (Nickel and Elzinga 1970a), which suggests similar feeding habits throughout ontogeny.

*Micromegistus bakeri* probably colonize new individuals of *S. subterraneus* during mating, if beetles rest near each other during the day (e.g., under a rock or log), or if new hosts enter the burrow as mites were seen to transfer between adult beetles when reared together (Nickel 1969, Riggins 2023).

The life history of other *Micromegistus* species is unknown beyond basic collecting information. Immatures of *M. viduus* have been found on ground beetle hosts, as have immatures of undescribed *Micromegistus* species from Brazil (on leafcutter ants) and Australia (on carabids) (Kim and Castagnoli 2010; Seeman and Nahrung 2000; O. Seeman pers. comm. 2024). This suggests that the immatures of all species in the genus live on the host, indicating an intimate association with the host beyond phoresy, like for *M. bakeri*.

## Mites associated with *Scarites* and other carabids

Parantennulidae is one of at least 24 mite families that have species associated with carabid beetles worldwide (Haitlinger 1988, Fain *et al.* 1995, Trach 2016, Seeman and Baker 2013, Trach and Seeman 2014). Most of these mites are phoretic on their host, using it mostly or only for dispersal as deutonymphs or adult females, or as both adult males and females in the case of Antennophorina. Other than that, they spend their life in soil-litter or other detrital habitat (e.g., dead wood) as predators of small invertebrates (most Mesostigmata), scavengers (some Antennophorina) or fungivores (e.g., Acaridae, Scutacaridae). These phoretic mites are associated with a few to many species of Carabidae (e.g., *Antennoseius* spp., Ascidae) or form loose associations with various beetle groups (e.g., some Macrochelidae) or even other arthropods (many Acaridae; Parasitidae). Fewer families include permanent associates of carabids that live under the elytra of their hosts as parasites (e.g., Podapolipidae: *Eutarsopolipus*) or putatively commensals or paraphages (e.g., Canestriniidae) (Nickel and Elzinga 1969, Katlav *et al.* 2015, Seeman 2021, Haitlinger 1988).

Nickel's work in Kansas shows that *Scarites subterraneus* is no exception and has many (at least eight) mite associates, including phoretic symbionts such as occasional predators (Ascidae: *Antennoseius* sp.; Parasitidae sp.), fungivores (Acaridae sp.) and common microbivores (Histiostomatidae sp.), as well as more intimate symbionts, namely two antennophorines, *M. bakeri* and *Echinomegistus wheeleri* Wasmann (Table 5; Nickel 1969, Nickel and Elzinga 1969, 1970a, 1970b). Based on Nickel's survey (1969), *Micromegistus bakeri* is the most common mite species occurring on *S. subterraneus*, with 57% of all (263) mites found on that carabid species; histiostomatids were second, with 34% of all mites, and then *E. wheeleri* with 6%; other mites were relatively rare, with 1–4 mites found in total on *S. subterraneus*. One of those rare mites was *Caraboacarus karenae* (Caraboacaridae), although common on other carabid species (Nickel and Elzinga 1969). Caraboacarids have unknown feeding habits and obscure relationships with their carabid hosts, with only adult females found on them (Katlav *et al.* 2015). Like *M. bakeri*, *Echinomegistus wheeleri* appears primarily associated with *S*.
(2012), recently described in Australia may have a somewhat analogous lifestyle to *M. bakeri*. Like *M. bakeri*, all life stages of *K. walteri* appear to live on the host, *Trichosternus perater* (Pterostichini), a burrowing carabid unrelated to *Scarites* spp. Like *S. subterraneus*, *T. perater* brings captured prey into its burrow, where *K. walteri* possibly feeds on microfauna associated with the prey items, such as nematodes, but may also scavenge the rotting prey itself (Seeman 2012; O. Seeman pers. comm. 2024).

Phoretic histiostomatid deutonymphs, which are occasionally found sharing the same host as *M. bakeri*, were not attacked by *M. bakeri* when both were found on the same host (Nickel and Elzinga 1970a, Nickel 1969, Riggins 2023). Indeed, the weakly, nearly edentate chelicerae of *M. bakeri*, with their mop-like appendages, do not appear optimal for seizing active prey, but rather for mopping up fluids, such as those oozing out of dead invertebrates, a behavior seen in other Trigynaspida (Seeman 2000). The larvae, nymphs and adult females and males all having similar chelicerae (Nickel and Elzinga 1970a), which suggests similar feeding habits throughout ontogeny.

*Micromegistus bakeri* probably colonize new individuals of *S. subterraneus* during mating, if beetles rest near each other during the day (e.g., under a rock or log), or if new hosts enter the burrow as mites were seen to transfer between adult beetles when reared together (Nickel 1969, Riggins 2023).

The life history of other *Micromegistus* species is unknown beyond basic collecting information. Immatures of *M. viduus* have been found on ground beetle hosts, as have immatures of undescribed *Micromegistus* species from Brazil (on leafcutter ants) and Australia (on carabids) (Kim and Castagnoli 2010; Seeman and Nahrung 2000; O. Seeman pers. comm. 2024). This suggests that the immatures of all species in the genus live on the host, indicating an intimate association with the host beyond phoresy, like for *M. bakeri*.

## Mites associated with *Scarites* and other carabids

Parantennulidae is one of at least 24 mite families that have species associated with carabid beetles worldwide (Haitlinger 1988, Fain *et al.* 1995, Trach 2016, Seeman and Baker 2013, Trach and Seeman 2014). Most of these mites are phoretic on their host, using it mostly or only for dispersal as deutonymphs or adult females, or as both adult males and females in the case of Antennophorina. Other than that, they spend their life in soil-litter or other detrital habitat (e.g., dead wood) as predators of small invertebrates (most Mesostigmata), scavengers (some Antennophorina) or fungivores (e.g., Acaridae, Scutacaridae). These phoretic mites are associated with a few to many species of Carabidae (e.g., *Antennoseius* spp., Ascidae) or form loose associations with various beetle groups (e.g., some Macrochelidae) or even other arthropods (many Acaridae; Parasitidae). Fewer families include permanent associates of carabids that live under the elytra of their hosts as parasites (e.g., Podapolipidae: *Eutarsopolipus*) or putatively commensals or paraphages (e.g., Canestriniidae) (Nickel and Elzinga 1969, Katlav *et al.* 2015, Seeman 2021, Haitlinger 1988).

Nickel's work in Kansas shows that *Scarites subterraneus* is no exception and has many (at least eight) mite associates, including phoretic symbionts such as occasional predators (Ascidae: *Antennoseius* sp.; Parasitidae sp.), fungivores (Acaridae sp.) and common microbivores (Histiostomatidae sp.), as well as more intimate symbionts, namely two antennophorines, *M. bakeri* and *Echinomegistus wheeleri* Wasmann (Table 5; Nickel 1969, Nickel and Elzinga 1969, 1970a, 1970b). Based on Nickel's survey (1969), *Micromegistus bakeri* is the most common mite species occurring on *S. subterraneus*, with 57% of all (263) mites found on that carabid species; histiostomatids were second, with 34% of all mites, and then *E. wheeleri* with 6%; other mites were relatively rare, with 1–4 mites found in total on *S. subterraneus*. One of those rare mites was *Caraboacarus karenae* (Caraboacaridae), although common on other carabid species (Nickel and Elzinga 1969). Caraboacarids have unknown feeding habits and obscure relationships with their carabid hosts, with only adult females found on them (Katlav *et al.* 2015). Like *M. bakeri*, *Echinomegistus wheeleri* appears primarily associated with *S*.
<table><caption>**Table 5** Mites recorded from *Scarites* species and their distribution based on published records (*S. subterraneus* indicated in bold). Undescribed mite species or species determined only to family or genus level are not included here (see main text or Nickel for such species associated with *S. subterraneus*).</caption><thead><tr><th>Order</th><th>Family</th><th>Species</th><th>Host</th><th>Range</th><th>References</th></tr></thead><tbody><tr><td>Mesostigmata (Gamasina)</td><td>Laelapidae</td><td>Gaeolaelaps scarites Joharchi & Saeidi, 2019</td><td>Scarites terricola Bonelli, 1813</td><td>Iran</td><td>Saeidi et al. 2019</td></tr><tr><td rowspan="2">Mesostigmata (Trigynaspida)</td><td>Paramegistidae</td><td>Echinomegistus wheeleri Wasmann, 1903</td><td>S. subterraneus Fabricius, 1775</td><td>USA (Kansas)</td><td>Nickel and Elzinga 1970b</td></tr><tr><td>Parantennulidae</td><td>Micromegistus barkeri Trägårdh, 1948</td><td>S. subterraneus</td><td>Canada, USA (see Fig. 3)</td><td>Nickel and Elzinga 1970a; this paper</td></tr><tr><td rowspan="7">Trombidiformes (Heterostigmata)</td><td rowspan="2">Schizogyniidae</td><td>M. viduus (Berlese, 1888)</td><td>Scarites sp.</td><td>Paraguay</td><td>Kim and Castagnoli 2010</td></tr><tr><td>Euroschizogynium calvum Trach & Seeman, 2014</td><td>S. terricola</td><td>Ukraine</td><td>Trach and Seeman 2014</td></tr><tr><td>Caraboacaridae</td><td>Caraboacarus karenae Nickel & Elzinga, 1969</td><td>S. subterraneus + 7 other carabid species</td><td>USA (Kansas)</td><td>Nickel and Elzinga 1969</td></tr><tr><td>Podapolipidae</td><td>Eutarsopolipus lagenaeformis (Berlese, 1911)</td><td>S. buparius (J. R. Forster, 1771)</td><td>Italy</td><td>Husband and Baker 2000</td></tr><tr><td rowspan="3">Scutacaridae</td><td>E. scariteus Husband, 2001</td><td>S. subterraneus</td><td>USA (Louisiana)</td><td>Husband 2001</td></tr><tr><td>E. terricolae Hajiqanbar & Mortazavi, 2012</td><td>S. terricola</td><td>Iran</td><td>Hajiqanbar and Mortazavi 2012</td></tr><tr><td>E. weatherbyi Husband & Psalmonds, 2004</td><td>Scarites sp.</td><td>Argentina</td><td>Husband and Psalmonds 2004</td></tr><tr><td></td><td></td><td>Heterodispus turkmenistaniensis Khaustov & Chydyrov, 2005</td><td>S. procerus eurytus (Fischer von Waldheim, 1828)</td><td>Iran, Turkmenistan</td><td>Sobhi et al. 2017; Baumann 2024</td></tr></tbody></table>

*subterraneus* and seem to have a similar feeding behavior as *M. bakeri*, although only adult males and females are found on the beetle, with immatures probably developing in soil or the carabid's tunnels (Nickel and Elzinga 1970b). More recently, a parasitic mite, *Eutarsopolipus scariteus* Husband (2001) (Podapolipidae) was described from *S. subterraneus* in Louisiana.

We hypothesize that carabids that have a stronger tendency to burrow have more mite symbionts, especially those that use the host for more than phoresy, as indicated by the presence of both sexes or immatures on the host. Such intimate symbionts would also be favored by a long-term usage of the burrows by the host, since this facilitates access to food resources such as partly eaten prey and to potential mates, with a relative ease of finding and reembarking on the host. It is unclear how much the same shelters are re-used by *Scarites* species in natural habitats, besides those used for overwintering in the northern parts of its geographic range. Among the approximately 200 described species of *Scarites* worldwide (Ball and Bousquet 2000, Bousquet 2012), only a few (four species plus two identified only as *Scarites* sp.) are recorded to host mites (Table 5). That <2% of *Scarites* species have recorded mite associates is striking when *S. subterraneus* has eight taxa of mites associated with it, including three that are host specialists (or nearly so) like *M. bakeri* (Nickel 1969, Husband 2001). Presuming this lack of mite associates is an artifact of sampling and reporting bias, it suggests that there are many *Scarites*-mite associations left to discover, depending on the number of mite species per beetle species and their degree of host specificity. The same could be said about the >1800 species of carabids of the subfamily *Scaritinae* (Bousquet 2012), most of which also have subterranean lifestyle, but for which we are aware of only a few mite species reported on them (Eidelberg 1994; Hogan 2012; Katlav *et al.* 2015, 2021; Arndt *et al.* 2016; Seeman 2020).

## Conclusions

*Micromegistus bakeri* appears to prefer *Scarites subterraneus* given its prevalence and abundance on that species compared to non-*Scarites* carabids. We also detected what are likely *M. bakeri* on other *Scarites* species, although these observations need to be confirmed through field-collected specimens examined in hand. Additional work is needed to understand the relationship between *M. bakeri* and its host(s), as well as infestation rates across geographical
<table><caption>**Table 5** Mites recorded from *Scarites* species and their distribution based on published records (*S. subterraneus* indicated in bold). Undescribed mite species or species determined only to family or genus level are not included here (see main text or Nickel for such species associated with *S. subterraneus*).</caption><thead><tr><th>Order</th><th>Family</th><th>Species</th><th>Host</th><th>Range</th><th>References</th></tr></thead><tbody><tr><td>Mesostigmata<br>(Gamasina)</td><td>Laelapidae</td><td>Gaeolaelaps scarites Joharchi & Saeidi,<br>2019</td><td>Scarites terricola Bonelli, 1813</td><td>Iran</td><td>Saeidi et al. 2019</td></tr><tr><td rowspan="2">Mesostigmata<br>(Trigynaspida)</td><td>Paramegistidae</td><td>Echinomegistus wheeleri Wasmann, 1903</td><td>S. subterraneus Fabricius, 1775</td><td>USA (Kansas)</td><td>Nickel and Elzinga 1970b</td></tr><tr><td>Parantennulidae</td><td>Micromegistus barkeri Trägårdh, 1948</td><td>S. subterraneus</td><td>Canada, USA (see Fig. 3)</td><td>Nickel and Elzinga 1970a; this<br>paper</td></tr><tr><td rowspan="2">Trombidiformes<br>(Heterostigmata)</td><td>Schizogyniidae</td><td>M. viduus (Berlese, 1888)<br>Euroschizogynium calvum Trach &<br>Seeman, 2014</td><td>Scarites sp.<br>S. terricola</td><td>Paraguay<br>Ukraine</td><td>Kim and Castagnoli 2010<br>Trach and Seeman 2014</td></tr><tr><td>Caraboacaridae</td><td>Caraboacarus karenae Nickel & Elzinga,<br>1969</td><td>S. subterraneus + 7 other carabid<br>species</td><td>USA (Kansas)</td><td>Nickel and Elzinga 1969</td></tr><tr><td rowspan="3">Podapolipidae</td><td></td><td>Eutarsopolipus lagenaeformis (Berlese,<br>1911)</td><td>S. buparius (J. R. Forster, 1771)</td><td>Italy</td><td>Husband and Baker 2000</td></tr><tr><td></td><td>E. scariteus Husband, 2001</td><td>S. subterraneus</td><td>USA (Louisiana)</td><td>Husband 2001</td></tr><tr><td></td><td>E. terricolae Hajiqanbar & Mortazavi,<br>2012</td><td>S. terricola</td><td>Iran</td><td>Hajiqanbar and Mortazavi<br>2012</td></tr><tr><td></td><td></td><td>E. weatherbyi Husband & Psalmonds,<br>2004</td><td>Scarites sp.</td><td>Argentina</td><td>Husband and Psalmonds 2004</td></tr><tr><td>Scutacaridae</td><td></td><td>Heterodispus turkmenistaniensis<br>Khaustov & Chydyrov, 2005</td><td>S. procerus eurytus (Fischer von<br>Waldheim, 1828)</td><td>Iran, Turkmenistan</td><td>Sobhi et al. 2017; Baumann<br>2024</td></tr></tbody></table>

*subterraneus* and seem to have a similar feeding behavior as *M. bakeri*, although only adult males and females are found on the beetle, with immatures probably developing in soil or the carabid's tunnels (Nickel and Elzinga 1970b). More recently, a parasitic mite, *Eutarsopolipus scariteus* Husband (2001) (Podapolipidae) was described from *S. subterraneus* in Louisiana.

We hypothesize that carabids that have a stronger tendency to burrow have more mite symbionts, especially those that use the host for more than phoresy, as indicated by the presence of both sexes or immatures on the host. Such intimate symbionts would also be favored by a long-term usage of the burrows by the host, since this facilitates access to food resources such as partly eaten prey and to potential mates, with a relative ease of finding and reembarking on the host. It is unclear how much the same shelters are re-used by *Scarites* species in natural habitats, besides those used for overwintering in the northern parts of its geographic range. Among the approximately 200 described species of *Scarites* worldwide (Ball and Bousquet 2000, Bousquet 2012), only a few (four species plus two identified only as *Scarites* sp.) are recorded to host mites (Table 5). That <2% of *Scarites* species have recorded mite associates is striking when *S. subterraneus* has eight taxa of mites associated with it, including three that are host specialists (or nearly so) like *M. bakeri* (Nickel 1969, Husband 2001). Presuming this lack of mite associates is an artifact of sampling and reporting bias, it suggests that there are many *Scarites*-mite associations left to discover, depending on the number of mite species per beetle species and their degree of host specificity. The same could be said about the >1800 species of carabids of the subfamily *Scaritinae* (Bousquet 2012), most of which also have subterranean lifestyle, but for which we are aware of only a few mite species reported on them (Eidelberg 1994; Hogan 2012; Katlav *et al.* 2015, 2021; Arndt *et al.* 2016; Seeman 2020).

## Conclusions

*Micromegistus bakeri* appears to prefer *Scarites subterraneus* given its prevalence and abundance on that species compared to non-*Scarites* carabids. We also detected what are likely *M. bakeri* on other *Scarites* species, although these observations need to be confirmed through field-collected specimens examined in hand. Additional work is needed to understand the relationship between *M. bakeri* and its host(s), as well as infestation rates across geographical
space and habitat types. The new confirmed and suspected records presented herein demon-
strate that the geographic distribution of *M. bakeri* is larger than previously documented and
likely mirrors that of *S. subterraneus*, which is widely distributed across the continental United
States (Figure 3). Finally, the high divergence between the COI sequence presented here and
the sequence available on BOLD suggests that there may be an interesting story to these easily
collected mites if anyone cares to investigate it.

Acknowledgements

We thank Hans Klompen for providing locality information for *M. bakeri* specimens housed in the Ohio State University Acarology Collection; Owen Seeman and another reviewer for valuable comments in a previous version of the manuscript; Eleanna Vasquez Cerda, Chloe Crabb, Joe Gallardo, Uma Riggins, Jim Crab, Carolyn Riggins, Rosa Walker, and Lem Riggins for their help in collecting specimens. This material is based upon work supported by the National Science Foundation under Grant No. NSF DEB 1762760/1556898 (T. Renner, PI). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. This work is supported by the USDA National Institute of Food and Agriculture and Hatch Appropriations under Project #PEN04974 and Accession #7006543.

ORCID

Nia Riggins https://orcid.org/0000-0001-7619-986X

Monica R. Young https://orcid.org/0000-0002-7388-8202

Tanya Renner https://orcid.org/0000-0003-0442-0056

Frédéric Beaulieu https://orcid.org/0000-0001-8383-9992

Michael Skvarla https://orcid.org/0000-0002-7102-3934

References

Arndt E, Beutel R.G., Will K. 2016. Carabidae Latreille, 1802. In: Beutel R.G., Leschen R.A.B. (Eds), Handbook of Zoology vol 4/38: Coleoptera beetles. vol 1. Morphology and systematics (Archostemata, Adephaga, Myxophaga, Polyphaga partim). 2nd Edition. Berlin: W DeGruyter. p. 162-190.

Ball G.E., Bousquet Y. 2000. Family 6. Carabidae. In: Arnett, R.H., Jr., and Thomas, M.C. (Eds.) American Beetles. Volume 1. Boca Raton, Florida: CRC Press. p. 32-132.

Baumann J. 2024. An update on the knowledge about scutacarid mites as phoronts and inquilines. Acarologia, 64(1): 3-17. https://doi.org/10.24349/sy16-8iqn

Berlese A. 1888. Acari Austro-Americani quos collegit Aloysius Balzan. Manipulus primus, species novas circiter quinquaginta complectens. Bullettino della Società entomologica italiana, 20: 171-222, plates V-XIII.

Berlese A. 1903. Illustrazione iconografica degli Acari mirmecofili. Redia, 1: 299-474, plates VII-XX

Bousquet Y. 2012. Catalogue of Geadephaga (Coleoptera, Adephaga) of America, north of Mexico. ZooKeys, 245: 1-1722. https://doi.org/10.3897/zookeys.245.3416

Ciegler J.C. 2000. Ground beetles and wrinkled bark beetles of South Carolina (Coleoptera: Geadephaga: Carabidae and Rhysodidae). Biota of South Carolina. Vol. 1. Clemson, South Carolina: Clemson University. pp. 149.

Dolezal A. 2019. Habitat-based drivers of arthropod abundance and richness in an intensively farmed agricultural landscape. [M.S. thesis]. Guelph, Canada: University of Guelph. pp. 121.

Eidelberg M.M. 1994. Mites of the family Podapolipidae (Heterostigmata, Tarsonemina) of Ukraine and adjacent areas with description of a new species. Vestnik Zoologii, 1994: 37-43.

Evenhuis N.L. 2024. The insect and spider collections of the world website [Internet]. [18 January 2024].
Available from http://hbs.bishopmuseum.org/codens/

Fabricius J.C. 1775. Systema entomologiae, sistens insectorum classes, ordines, genera, species adiectis synonymis, locis, descriptionibus, observationibus. Flensburgi et Lipsiae [= Flensburg and Leipzig]: Korte. pp. 832. https://doi.org/10.5962/bhl title.36510

Fain A., Noti M.I., Dufrêne M. 1995. Observations on the mites (Acari) associated with Carabidae (Coleoptera) in Belgium. I. Annotated list of the species. Int. J. Acarol., 21(2): 107-122.
https://doi.org/10.1080/01647959508684051
space and habitat types. The new confirmed and suspected records presented herein demon-
strate that the geographic distribution of *M. bakeri* is larger than previously documented and
likely mirrors that of *S. subterraneus*, which is widely distributed across the continental United
States (Figure 3). Finally, the high divergence between the COI sequence presented here and
the sequence available on BOLD suggests that there may be an interesting story to these easily
collected mites if anyone cares to investigate it.

Acknowledgements

We thank Hans Klompen for providing locality information for *M. bakeri* specimens housed in the Ohio State University Acarology Collection; Owen Seeman and another reviewer for valuable comments in a previous version of the manuscript; Eleanna Vasquez Cerda, Chloe Crabb, Joe Gallardo, Uma Riggins, Jim Crab, Carolyn Riggins, Rosa Walker, and Lem Riggins for their help in collecting specimens. This material is based upon work supported by the National Science Foundation under Grant No. NSF DEB 1762760/1556898 (T. Renner, PI). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation. This work is supported by the USDA National Institute of Food and Agriculture and Hatch Appropriations under Project #PEN04974 and Accession #7006543.

ORCID

Nia Riggins https://orcid.org/0000-0001-7619-986X

Monica R. Young https://orcid.org/0000-0002-7388-8202

Tanya Renner https://orcid.org/0000-0003-0442-0056

Frédéric Beaulieu https://orcid.org/0000-0001-8383-9992

Michael Skvarla https://orcid.org/0000-0002-7102-3934

References

Arndt E, Beutel R.G., Will K. 2016. Carabidae Latreille, 1802. In: Beutel R.G., Leschen R.A.B. (Eds), Handbook of Zoology vol 4/38: Coleoptera beetles. vol 1. Morphology and systematics (Archostemata, Adephaga, Myxophaga, Polyphaga partim). 2nd Edition. Berlin: W DeGruyter. p. 162-190.

Ball G.E., Bousquet Y. 2000. Family 6. Carabidae. In: Arnett, R.H., Jr., and Thomas, M.C. (Eds.) American Beetles. Volume 1. Boca Raton, Florida: CRC Press. p. 32-132.

Baumann J. 2024. An update on the knowledge about scutacarid mites as phoronts and inquilines. Acarologia, 64(1): 3-17. https://doi.org/10.24349/sy16-8iqn

Berlese A. 1888. Acari Austro-Americani quos collegit Aloysius Balzan. Manipulus primus, species novas circiter quinquaginta complectens. Bullettino della Società entomologica italiana, 20: 171-222, plates V-XIII.

Berlese A. 1903. Illustrazione iconografica degli Acari mirmecofili. Redia, 1: 299-474, plates VII-XX

Bousquet Y. 2012. Catalogue of Geadephaga (Coleoptera, Adephaga) of America, north of Mexico. ZooKeys, 245: 1-1722. https://doi.org/10.3897/zookeys.245.3416

Ciegler J.C. 2000. Ground beetles and wrinkled bark beetles of South Carolina (Coleoptera: Geadephaga: Carabidae and Rhysodidae). Biota of South Carolina. Vol. 1. Clemson, South Carolina: Clemson University. pp. 149.

Dolezal A. 2019. Habitat-based drivers of arthropod abundance and richness in an intensively farmed agricultural landscape. [M.S. thesis]. Guelph, Canada: University of Guelph. pp. 121.

Eidelberg M.M. 1994. Mites of the family Podapolipidae (Heterostigmata, Tarsonemina) of Ukraine and adjacent areas with description of a new species. Vestnik Zoologii, 1994: 37-43.

Evenhuis N.L. 2024. The insect and spider collections of the world website [Internet]. [18 January 2024].
Available from http://hbs.bishopmuseum.org/codens/

Fabricius J.C. 1775. Systema entomologiae, sistens insectorum classes, ordines, genera, species adiectis synonymis, locis, descriptionibus, observationibus. Flensburgi et Lipsiae [= Flensburg and Leipzig]: Korte. pp. 832. https://doi.org/10.5962/bhl title.36510

Fain A., Noti M.I., Dufrêne M. 1995. Observations on the mites (Acari) associated with Carabidae (Coleoptera) in Belgium. I. Annotated list of the species. Int. J. Acarol., 21(2): 107-122.
https://doi.org/10.1080/01647959508684051
Folmer O., Black M., Hoeh W., Lutz R., Vrijenhoek R. 1994. DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. Mol. Mar. Biol. Biotechnol., 3(5): 294-299.

Haitlinger R. 1988. Mites (Acari) occurring on beetles of the genus *Carabus* Linnaeus, 1758 (Insecta, Coleoptera, Carabidae). Wiad. Parazytol., 34: 329-346.

Hajiqanbar H., Mortazavi A. 2012. First record of the *myzus* species group (Acari: Podapolipidae: *Eutarsopolipus* Berlese, 1911) from Asia, with the description of two new species parasitising carabid beetles. Syst. Parasitol., 83: 189-202. https://doi.org/10.1007/s11230-012-9384-5

Hamilton-Smith E. 1967. The Arthropoda of Australian caves. Aus. J. Entomol., 6(2): 103-118. https://doi.org/10.1111/j.1440-6055.1967.tb02123.x

Hebert P.D.N., Cywinska A., Ball S.L., deWaard J.R. 2003. Biological identifications through DNA barcodes. Proc. Biol. Sci., 270(1512): 313-321. https://doi.org/10.1098/rspb.2002.2218

Hlavac T.F. 1967. Observations on behavior in *Scarites* (Coleoptera: Carabidae: Scaritini). Coleopterists Bull., 21(1): 18-22.

Hogan J. 2012. Taxonomy, Systematics and Biogeography of the Scaritinae (Insecta, Coleoptera, Carabidae) [Ph.D. thesis]. Oxford, England: Oxford Brookes University. pp. 288.

Husband R.W. 2001. A new species of *Eutarsopolipus* (Acari: Podapolipidae) from *Scarites subterraneus* (Coleoptera: Carabidae) from Louisiana, U.S.A. Int. J. Acarol., 27: 113-117. 10.1080/01647950108684238 https://doi.org/10.1080/01647950108684238

Husband R.W., Baker A. 2000. Redescription of *Eutarsopolipus* (*Tarsopolipus* lagenaeformis (Acari: Podapolipidae) from *Scarites buparius* (Coleoptera: Carabidae). Ann. Entomol. Soc. Am., 93(4): 707-712. https://doi.org/10.1603/0013-8746(2000)093%5B0707:ROETLA%5D2.0.CO;2

Husband R.W., Psalmonds L. 2004. A new species of *Eutarsopolipus* (Acari: Podapolipidae) from *Scarites* sp. (Coleoptera: Carabidae) from Argentina, Int. J. Acarol., 30(2): 107-112. https://doi.org/10.1080/01647950408684377

Johnston D.E., Johnston G.E., DeGuisti D.L. 1947. Observations on *Micromegistus bakeri* Trägårdh, 1948 (Acarina: Mesostigmata: Parantennulidae) an antennophoroid mite occurring on *Scarites* beetles. J. Parasitol., 43(5) Section 2 (Suppl.): 35.

Katlav A., Hajiqanbar H., Riegler M., Seeman O.D. 2021. Sheltered life beneath elytra: three new species of *Eutarsopolipus* (Acari, Heterostigmatina, Podapolipidae) parasitizing Australian ground beetles. Parasite, 28: 1-21. https://doi.org/10.1051/parasite/2021069

Katlav A., Hajiqanbar H., Talebi A.A. 2015. A new genus and species of mites of the family Caraboacariidae (Acari: Heterostigmata) associated with *Clivina ypsilon* (Coleoptera: Carabidae) with notes on distribution and host range of the family. Can. Entomol., 147(4): 370-380 https://doi.org/10.4039/tce.2014.61

Kethley J.B. 1977. A review of the higher categories of *Trigynaspida* (Acari: Parasitiformes). Int. J. Acarol., 3(2): 129-149. https://doi.org/10.1080/01647957708683090

Kim C.-M. 2004. *Trigynaspida* (Acari: Mesostigmata): new diagnosis, classification, and phylogeny. *Acarologia*, 44: 157-194.

Kim C.-M., Castagnoli M. 2010. Parantennulidae: What's in the family? (Acari: Mesostigmata: *Trigynaspida*). Int. J. Acarol., 36(5): 409-412. https://doi.org/10.1080/01647954.2010.488250

Larochelle A., Larivière M.-C. 2003. A natural history of the ground-beetles (Coleoptera: Carabidae) of American north of Mexico. Sofia, Bulgaria: Pensoft. pp. 583.

Li J.-B., Li Y.-X., Sun J.-T., Xue X.-F., Xu X.-N., Hong X.-Y. 2012. COI barcoding as a molecular assay for the identification of phytoseiid mites. Sys. Appl. Acarol., 17: 397-406. https://doi.org/10.11158/saa.17.4.8

Mathis K.A., Bronstein J.L. 2020. Our current understanding of commensalism. Ann. Rev. Ecol. Evol. Syst., 51: 167-189 https://doi.org/10.1146/annurev-ecolsys-011720-040844

McDaniel B., Bolen E.G. 1979. New distribution record for *Micromegistus bakeri* Trägårdh (Acarina: Parantennulidae). Entomol. News, 90(3): 149-150.

Mizser S. 2016. Mite infection of *Carabus violaceus* in rural forest patches and urban parks. Periodicum Biologorum, 118: 307-309. https://doi.org/10.18054/pb.2016.118.3.3925

Nickel P.A. 1969. Ectosymbiotic mites associated with certain carabid beetles of Kansas [PhD thesis]. Manhattan, Kansas: Kansas State University. pp. 88.

Nickel P.A., Elzinga R.J. 1969. *Caraboacarus karenae*, a new mite from carabid beetles, with notes on its biology (Acari: Pyemotidae). J. Kansas Entomol. Soc., 42: 222-229.

Nickel P.A., Elzinga R.J. 1970a. Biology of *Micromegistus bakeri* Trägårdh, 1948 (Acarina: Parantennulidae) with descriptions of immatures and redescription of adults. Acarologia, 12(2): 234-243.

Nickel P.A., Elzinga R.J. 1970b. New host records and biological notes for *Echinomegistus wheeleri* (Wasmann) (Acarina: Paramegistidae). J. Kansas Entomol. Soc., 43(1): 32-34.

Nowell V., Schwarzfeld M. 2019. First record of the mite genus *Denheyernaxoides* Smiley (Acari: Bdelloidea: Cunaxidae) for North America and a redescription of *D. americanus* Rocha *et al*. Sys. Appl. Acarol., 24: 477-486. https://doi.org/10.11158/saa.24.3.11

Riggins N. 2023. Why *Scarites*? A commensal relationship between a mite and a ground beetle. [MS Thesis]. State College, Pennsylvania: Pennsylvania State University. pp. 57.

Saeidi S., Maroufpoor M., Hajiqanbar H., Joharchi O. 2019. *Gaeolaelaps scarites* sp. nov., a new laelapid mite (Acari: Mesostigmata) associated with *Scarites terricola* (Coleoptera: Carabidae) from Iran. Int. J. Acarol., 45(3): 119-124. https://doi.org/10.1080/01647954.2018.1554701

Seeman O.D. 2012. A new genus of *Blattisociidae* (Acari: Mesostigmata: Phytoseioidea) from Australian burrowing carabid beetles. Int. J. Acar., 38: 533-544. https://doi.org/10.1080/01647954.2012.704395

Seeman O.D. 2000. Life cycle, development, feeding and immature life stages of the *Fedrizziidae* (Mesostigmata: *Fedrizzioidea*). Acarologia, 41: 39-52.
Folmer O., Black M., Hoeh W., Lutz R., Vrijenhoek R. 1994. DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates. Mol. Mar. Biol. Biotechnol., 3(5): 294-299.

Haitlinger R. 1988. Mites (Acari) occurring on beetles of the genus *Carabus* Linnaeus, 1758 (Insecta, Coleoptera, Carabidae). Wiad. Parazytol., 34: 329-346.

Hajiqanbar H., Mortazavi A. 2012. First record of the *myzus* species group (Acari: Podapolipidae: *Eutarsopolipus* Berlese, 1911) from Asia, with the description of two new species parasitising carabid beetles. Syst. Parasitol., 83: 189-202. https://doi.org/10.1007/s11230-012-9384-5

Hamilton-Smith E. 1967. The Arthropoda of Australian caves. Aus. J. Entomol., 6(2): 103-118. https://doi.org/10.1111/j.1440-6055.1967.tb02123.x

Hebert P.D.N., Cywinska A., Ball S.L., deWaard J.R. 2003. Biological identifications through DNA barcodes. Proc. Biol. Sci., 270(1512): 313-321. https://doi.org/10.1098/rspb.2002.2218

Hlavac T.F. 1967. Observations on behavior in *Scarites* (Coleoptera: Carabidae: Scaritini). Coleopterists Bull., 21(1): 18-22.

Hogan J. 2012. Taxonomy, Systematics and Biogeography of the Scaritinae (Insecta, Coleoptera, Carabidae) [Ph.D. thesis]. Oxford, England: Oxford Brookes University. pp. 288.

Husband R.W. 2001. A new species of *Eutarsopolipus* (Acari: Podapolipidae) from *Scarites subterraneus* (Coleoptera: Carabidae) from Louisiana, U.S.A. Int. J. Acarol., 27: 113-117. 10.1080/01647950108684238 https://doi.org/10.1080/01647950108684238

Husband R.W., Baker A. 2000. Redescription of *Eutarsopolipus* (*Tarsopolipus* lagenaeformis (Acari: Podapolipidae) from *Scarites buparius* (Coleoptera: Carabidae). Ann. Entomol. Soc. Am., 93(4): 707-712. https://doi.org/10.1603/0013-8746(2000)093%5B0707:ROETLA%5D2.0.CO;2

Husband R.W., Psalmonds L. 2004. A new species of *Eutarsopolipus* (Acari: Podapolipidae) from *Scarites* sp. (Coleoptera: Carabidae) from Argentina, Int. J. Acarol., 30(2): 107-112. https://doi.org/10.1080/01647950408684377

Johnston D.E., Johnston G.E., DeGuisti D.L. 1947. Observations on *Micromegistus bakeri* Trägårdh, 1948 (Acarina: Mesostigmata: Parantennulidae) an antennophoroid mite occurring on *Scarites* beetles. J. Parasitol., 43(5) Section 2 (Suppl.): 35.

Katlav A., Hajiqanbar H., Riegler M., Seeman O.D. 2021. Sheltered life beneath elytra: three new species of *Eutarsopolipus* (Acari, Heterostigmatina, Podapolipidae) parasitizing Australian ground beetles. Parasite, 28: 1-21. https://doi.org/10.1051/parasite/2021069

Katlav A., Hajiqanbar H., Talebi A.A. 2015. A new genus and species of mites of the family Caraboacariidae (Acari: Heterostigmata) associated with *Clivina ypsilon* (Coleoptera: Carabidae) with notes on distribution and host range of the family. Can. Entomol., 147(4): 370-380 https://doi.org/10.4039/tce.2014.61

Kethley J.B. 1977. A review of the higher categories of *Trigynaspida* (Acari: Parasitiformes). Int. J. Acarol., 3(2): 129-149. https://doi.org/10.1080/01647957708683090

Kim C.-M. 2004. *Trigynaspida* (Acari: Mesostigmata): new diagnosis, classification, and phylogeny. *Acarologia*, 44: 157-194.

Kim C.-M., Castagnoli M. 2010. Parantennulidae: What's in the family? (Acari: Mesostigmata: *Trigynaspida*). Int. J. Acarol., 36(5): 409-412. https://doi.org/10.1080/01647954.2010.488250

Larochelle A., Larivière M.-C. 2003. A natural history of the ground-beetles (Coleoptera: Carabidae) of American north of Mexico. Sofia, Bulgaria: Pensoft. pp. 583.

Li J.-B., Li Y.-X., Sun J.-T., Xue X.-F., Xu X.-N., Hong X.-Y. 2012. COI barcoding as a molecular assay for the identification of phytoseiid mites. Sys. Appl. Acarol., 17: 397-406. https://doi.org/10.11158/saa.17.4.8

Mathis K.A., Bronstein J.L. 2020. Our current understanding of commensalism. Ann. Rev. Ecol. Evol. Syst., 51: 167-189 https://doi.org/10.1146/annurev-ecolsys-011720-040844

McDaniel B., Bolen E.G. 1979. New distribution record for *Micromegistus bakeri* Trägårdh (Acarina: Parantennulidae). Entomol. News, 90(3): 149-150.

Mizser S. 2016. Mite infection of *Carabus violaceus* in rural forest patches and urban parks. Periodicum Biologorum, 118: 307-309. https://doi.org/10.18054/pb.2016.118.3.3925

Nickel P.A. 1969. Ectosymbiotic mites associated with certain carabid beetles of Kansas [PhD thesis]. Manhattan, Kansas: Kansas State University. pp. 88.

Nickel P.A., Elzinga R.J. 1969. *Caraboacarus karenae*, a new mite from carabid beetles, with notes on its biology (Acari: Pyemotidae). J. Kansas Entomol. Soc., 42: 222-229.

Nickel P.A., Elzinga R.J. 1970a. Biology of *Micromegistus bakeri* Trägårdh, 1948 (Acarina: Parantennulidae) with descriptions of immatures and redescription of adults. Acarologia, 12(2): 234-243.

Nickel P.A., Elzinga R.J. 1970b. New host records and biological notes for *Echinomegistus wheeleri* (Wasmann) (Acarina: Paramegistidae). J. Kansas Entomol. Soc., 43(1): 32-34.

Nowell V., Schwarzfeld M. 2019. First record of the mite genus *Denheyernaxoides* Smiley (Acari: Bdelloidea: Cunaxidae) for North America and a redescription of *D. americanus* Rocha *et al*. Sys. Appl. Acarol., 24: 477-486. https://doi.org/10.11158/saa.24.3.11

Riggins N. 2023. Why *Scarites*? A commensal relationship between a mite and a ground beetle. [MS Thesis]. State College, Pennsylvania: Pennsylvania State University. pp. 57.

Saeidi S., Maroufpoor M., Hajiqanbar H., Joharchi O. 2019. *Gaeolaelaps scarites* sp. nov., a new laelapid mite (Acari: Mesostigmata) associated with *Scarites terricola* (Coleoptera: Carabidae) from Iran. Int. J. Acarol., 45(3): 119-124. https://doi.org/10.1080/01647954.2018.1554701

Seeman O.D. 2012. A new genus of *Blattisociidae* (Acari: Mesostigmata: Phytoseioidea) from Australian burrowing carabid beetles. Int. J. Acar., 38: 533-544. https://doi.org/10.1080/01647954.2012.704395

Seeman O.D. 2000. Life cycle, development, feeding and immature life stages of the *Fedrizziidae* (Mesostigmata: *Fedrizzioidea*). Acarologia, 41: 39-52.
Seeman O.D. 2020. Unusual new species of Australian *Eutarsopolipus* (Acariformes: Podapolipidae) from *Clivina* (Coleoptera: Carabidae). Annales Zoologici, 70: 425-438. https://doi.org/10.3161/00034541ANZ2020.70.3.013

Seeman O.D. 2021. Contrasting species diversification of *Eutarsopolipus* (Acariformes: Podapolipidae) on *Castelnaudia* and *Notonomus* (Coleoptera: Carabidae). Zootaxa, 4971: 1-74. https://doi.org/10.11646/zootaxa.4971.1.1

Seeman O.D., Baker M.R. 2013. A new genus and species of Discozerconidae (Acari: Mesostigmata) from carabid beetles (Coleoptera: Carabidae) in New Zealand. Zootaxa, 3750(2): 130-142. 10.11646/zootaxa.3750.2.2 https://doi.org/10.11646/zootaxa.3750.2.2

Seeman O.D., Nahrung H.F. 2000. Mites as fungal vectors? The ectoparasitic fungi of mites and their arthropod associates in Queensland. Austral. Mycol., 19: 3-9.

Seeman O.D., Walter D.E. 2023. Phoresy and mites: more than just a free ride. Ann. Rev. Entomol., 68: 69-88. https://doi.org/10.1146/annurev-ento-120220-013329

Skvarla M.J., Fisher J.R. 2023. Online community photo-sharing in entomology: a large-scale review with suggestions on best practices. Ann. Entomol. Soc. Am., 116(5): 276-304. https://doi.org/10.1093/aesa/sad021

Trach V.A. 2016. New records of carabid-associated mesostigmatic mites (Acari: Mesostigmata) from Ukraine with description of adults of *Halodarcia carabidophila* Evans and Fain, 1995 (Halolaelapidae). *Acarologia*, 56 (4): 587-601. https://doi.org/10.1051/acarologia/20164146

Trach V.A., Seeman O.D. 2014. A new genus and species of Schizogyniidae (Acari: Mesostigmata) associated with carabid beetles (Coleoptera: Carabidae) from Ukraine. Zootaxa, 3793(2): 247-256. https://doi.org/10.11646/zootaxa.3793.2.4

Trägårdh I. 1948. Description of *Micromegistus*, a new genus of the Paramegistidae, with notes on *Neomegistus*, *Paramegistus*, and *Echinomegistus* (Acarina). Ent. Tidsk. Stockholm, (69): 127-131.

Willmann C. 1940. Neue Milben aus Höhlen der Balkanhalbinsel, gesammelt von Prof. Dr. K. Absolon, Brünn. Zool. Anz., 130: 209-218.

Womersley H. 1958. Some new or little known Mesostigmata (Acarina) from Australia, New Zealand and Malaya. Trans. R. Soc. South Aust., 81: 115-130.

Young M.R., Moraza M.L., Ueckermann E., Heylen D., Baardsen L.F., Lima-Barbero J.F., Gal S., Gavish-Regev E., Gottlieb Y., Roy L., Recht E., El Adouzi M., Palevsky E. 2019. Linking morphological and molecular taxonomy for the identification of poultry house, soil, and nest dwelling mites in the Western Palearctic. Sci. Rep. https://doi.org/10.1038/s41598-019-41958-9
Seeman O.D. 2020. Unusual new species of Australian *Eutarsopolipus* (Acariformes: Podapolipidae) from *Clivina* (Coleoptera: Carabidae). Annales Zoologici, 70: 425-438. https://doi.org/10.3161/00034541ANZ2020.70.3.013

Seeman O.D. 2021. Contrasting species diversification of *Eutarsopolipus* (Acariformes: Podapolipidae) on *Castelnaudia* and *Notonomus* (Coleoptera: Carabidae). Zootaxa, 4971: 1-74. https://doi.org/10.11646/zootaxa.4971.1.1

Seeman O.D., Baker M.R. 2013. A new genus and species of Discozerconidae (Acari: Mesostigmata) from carabid beetles (Coleoptera: Carabidae) in New Zealand. Zootaxa, 3750(2): 130-142. 10.11646/zootaxa.3750.2.2 https://doi.org/10.11646/zootaxa.3750.2.2

Seeman O.D., Nahrung H.F. 2000. Mites as fungal vectors? The ectoparasitic fungi of mites and their arthropod associates in Queensland. Austral. Mycol., 19: 3-9.

Seeman O.D., Walter D.E. 2023. Phoresy and mites: more than just a free ride. Ann. Rev. Entomol., 68: 69-88. https://doi.org/10.1146/annurev-ento-120220-013329

Skvarla M.J., Fisher J.R. 2023. Online community photo-sharing in entomology: a large-scale review with suggestions on best practices. Ann. Entomol. Soc. Am., 116(5): 276-304. https://doi.org/10.1093/aesa/saad021

Trach V.A. 2016. New records of carabid-associated mesostigmatic mites (Acari: Mesostigmata) from Ukraine with description of adults of *Halodarcia carabidophila* Evans and Fain, 1995 (Halolaelapidae). *Acarologia*, 56 (4): 587-601. https://doi.org/10.1051/acarologia/20164146

Trach V.A., Seeman O.D. 2014. A new genus and species of Schizogyniidae (Acari: Mesostigmata) associated with carabid beetles (Coleoptera: Carabidae) from Ukraine. Zootaxa, 3793(2): 247-256. https://doi.org/10.11646/zootaxa.3793.2.4

Trägårdh I. 1948. Description of *Micromegistus*, a new genus of the Paramegistidae, with notes on *Neomegistus*, *Paramegistus*, and *Echinomegistus* (Acarina). Ent. Tidsk. Stockholm, (69): 127-131.

Willmann C. 1940. Neue Milben aus Höhlen der Balkanhalbinsel, gesammelt von Prof. Dr. K. Absolon, Brünn. Zool. Anz., 130: 209-218.

Womersley H. 1958. Some new or little known Mesostigmata (Acarina) from Australia, New Zealand and Malaya. Trans. R. Soc. South Aust., 81: 115-130.

Young M.R., Moraza M.L., Ueckermann E., Heylen D., Baardsen L.F., Lima-Barbero J.F., Gal S., Gavish-Regev E., Gottlieb Y., Roy L., Recht E., El Adouzi M., Palevsky E. 2019. Linking morphological and molecular taxonomy for the identification of poultry house, soil, and nest dwelling mites in the Western Palearctic. Sci. Rep. https://doi.org/10.1038/s41598-019-41958-9