DOI: 10.5061/dryad.v6wwpzh9q
title: Data from: Viral prevalence is higher, while relative infection loads are lower, in later developmental stages of a univoltine insect herbivore

description: Pathogens represent critical agents of mortality for insects, yet their
 ecological impacts remain poorly understood in many natural
 systems.  Developmental resistance (i.e., a reduction in disease
 susceptibility as hosts mature), along with age-related changes in ecology
 and behavior, are expected to give rise to variation in pathogen pressure
 across the host life cycle. However, the dynamics of pathogen infection
 across long larval periods such as those in diapausing insects are
 relatively unexplored. We used field-collected Euphydryas phaeton
 caterpillars (Lepidoptera: Nymphalidae) to evaluate how interactions with
 a naturally occurring entomopathogen, Junonia coenia densovirus, varied
 across host development and diapause. We compared the frequency and
 severity of viral infection during three stages of the life cycle:
 post-diapause, pre-diapause, and diapause. Field-collected post-diapause
 caterpillars were reared until death before viral screening, while
 field-collected pre-diapause caterpillars were subsampled for viral
 screening, allowing a portion to enter diapause to determine viral
 prevalence and load following overwintering. Viral prevalence was higher
 in post-diapause caterpillars, pupae, and adults, compared to relatively
 immature pre-diapause caterpillars. However, early-instar (pre-diapause)
 caterpillars that were infected with the virus harbored higher relative
 viral loads, compared to late-instar (post-diapause) caterpillars, pupae,
 and butterflies. In addition, viral prevalence was generally similar
 across sampling regions, while viral loads exhibited inconsistent regional
 differences across developmental stages. These results demonstrate that
 viral prevalence and load can vary considerably across the life cycle of
 an insect host and suggest that regional variation in infection severity
 may be more evident during certain stages of development than others.
 Moving forward, field and lab studies investigating the consequences of
 pathogen infection should consider host developmental stage, as infection
 parameters can change across development.
description: GENERAL INFORMATION 1. Title of Dataset: "Data from: Viral prevalence
 is higher, while relative infection loads are lower, in later
 developmental stages of a univoltine insect herbivore" 2. Author
 Information: A. Contact Information for Corresponding Author Name: Nadya
 D. Muchoney Institution: Emory University Address: Department of Biology,
 1510 Clifton Road NE, Atlanta, GA, 30322, USA Email:
 [nmuchon@emory.edu](mailto:nmuchon@emory.edu) B. Contact Information for
 Co-Authors Name: Adrian L. Carper Institution: University of Colorado,
 Boulder Address: Department of Ecology and Evolutionary Biology, 1900
 Pleasant Street, 334 UCB, Boulder, CO, 80309, USA Name: M. Deane Bowers
 Institution: University of Colorado, Boulder Address: Department of
 Ecology and Evolutionary Biology, 1900 Pleasant Street, 334 UCB, Boulder,
 CO, 80309, USA Name: Denali G. Lowder Institution: University of Nevada,
 Reno Address: Department of Biology, 1664 N. Virginia Street, MS 0314,
 Reno, NV, 89557, USA Name: Mike B. Teglas Institution: University of
 Nevada, Reno Address: Department of Agriculture, Veterinary, and Rangeland
 Sciences, 1664 N. Virginia Street, MS 0202, Reno, NV, 89557, USA Name:
 Angela M. Smilanich Institution: University of Nevada, Reno Address:
 Department of Biology, 1664 N. Virginia Street, MS 0314, Reno, NV, 89557,
 USA 3. Date of data collection: 2019–2020 4. Geographic location of data
 collection: Massachusetts, New York, and Vermont, USA (field sites);
 Colorado and Nevada, USA (laboratory sites) 5. Keywords: developmental
 resistance, diapause, entomopathogens, Euphydryas phaeton, Junonia coenia
 densovirus, tritrophic interactions 6. Funding sources: The collection of
 these data was supported by a National Science Foundation grant
 (DEB‐1929522) to AMS, MDB, and MBT, a National Science Foundation Graduate
 Research Fellowship (DGE‐1447692) to NDM, and a research grant from the
 E.N. Huyck Preserve and Biological Research Station. DATA & FILE
 OVERVIEW Ecol_Entomol_Dataset.csv: This file contains the dataset
 presented in our manuscript, including field sampling details and the
 results of quantitative PCR screening for Junonia coenia densovirus in
 Euphydryas phaeton individuals collected from wild populations in
 Massachusetts, New York, and Vermont, USA in 2019. METHODOLOGICAL
 INFORMATION Methodological details pertaining to this dataset are
 described in: Muchoney, N.D., Carper, A.L., Bowers, M.D., Lowder, D.G.,
 Teglas, M.B., Smilanich, A.M. Viral prevalence is higher, while relative
 infection loads are lower, in later developmental stages of a univoltine
 insect herbivore. Accepted, Ecological Entomology. DATA-SPECIFIC
 INFORMATION FOR: Ecol_Entomol_Dataset.csv 1. Number of variables: 30 2.
 Number of cases/rows: 479 3. Variable list: individual: Identifier for
 each Euphydryas phaeton individual sampled in 2019/2020 coll_region:
 Region from which each individual originated (MA = Massachusetts; NY = New
 York; VT = Vermont) coll_site: Site from which each individual originated
 (MA1, MA2, NY1, VT1, or VT2) host_plant: Host plant used at each site
 (Chelone = Chelone glabra; Plantago = Plantago lanceolata) coll_stage:
 Life stage at which each individual was collected from the field (POST =
 post-diapause larva, PRE = pre-diapause larva, EGG = egg) collate: Date
 upon which each individual was collected from the field
 (post-diapause/pre-diapause) or lab (overwintered) (MM/DD/YY) coll_time:
 Stage during which each individual was sampled for viral screening (POST =
 post-diapause, PRE = pre-diapause, OVWT = overwintered) cluster:
 Field-collected cluster from which each pre-diapause/diapause individual
 originated (unique for each post-diapause individual) cluster_size: Number
 of individuals within each field-collected cluster ('NA' for
 post-diapause individuals, which were collected independently) ecl_date:
 Observed date of eclosion for each butterfly (MM/DD/YY) (post-diapause
 butterflies only) sex: Sex of each butterfly as determined by visual
 inspection (F = Female, M = Male) (post-diapause butterflies only)
 death_date: Observed date of death for each butterfly (MM/DD/YY)
 (post-diapause butterflies only) death_stage: Life stage of each
 individual at time of death (LRV = Larva, PUP = Pupa, ADT = Adult)
 (post-diapause individuals only) survived: Whether each individual
 survived to reach the adult stage (Yes/No) (post-diapause individuals
 only) tot_mass: Total body mass of each individual at the time of DNA
 extraction (whole larva, pupa, or butterfly) (grams) abd_mass: Mass of the
 dissected abdomen used for DNA extraction and viral screening (grams)
 (post-diapause butterflies only) aliq_mass: Mass of the aliquot of
 homogenized tissue used for DNA extraction and viral screening (grams)
 (post-diapause larvae only) samp_mass: Mass of tissue sample used for DNA
 extraction and viral screening (grams) ct_vp4_1: Cycle threshold for
 detection of Junonia coenia densovirus (VP4 gene) via quantitative PCR;
 replicate 1 mt_vp4_1: Melt temperature (°C) for detection of Junonia
 coenia densovirus (VP4 gene) via quantitative PCR; replicate 1 ct_vp4_2:
 Cycle threshold for detection of Junonia coenia densovirus (VP4 gene) via
 quantitative PCR; replicate 2 mt_vp4_1: Melt temperature (°C) for
 detection of Junonia coenia densovirus (VP4 gene) via quantitative PCR;
 replicate 2 ct_vp4_3: Cycle threshold for detection of Junonia coenia
 densovirus (VP4 gene) via quantitative PCR; replicate 3 mt_vp4_1: Melt
 temperature (°C) for detection of Junonia coenia densovirus (VP4 gene) via
 quantitative PCR; replicate 3 ct_28s_1: Cycle threshold for detection of
 internal control gene (28S) via quantitative PCR; replicate 1 mt_28s_1:
 Melt temperature (°C) for detection of internal control gene (28S) via
 quantitative PCR; replicate 1 ct_28s_2: Cycle threshold for detection of
 internal control gene (28S) via quantitative PCR; replicate 2 mt_28s_2:
 Melt temperature (°C) for detection of internal control gene (28S) via
 quantitative PCR; replicate 2 ct_28s_3: Cycle threshold for detection of
 internal control gene (28S) via quantitative PCR; replicate 3 mt_28s_3:
 Melt temperature (°C) for detection of internal control gene (28S) via
 quantitative PCR; replicate 3 4. Missing data code: NA