DOI: 10.5061/dryad.t76hdr88p
title: Museum collections reveal a global range of Ophryocystis parasites in Danaus butterflies

description: Understanding the host range, patterns, and consequences of parasite
 infection is essential for detecting and responding to parasite-mediated
 insect declines. The debilitating protozoan Ophryocystis elektroscirrha
 (OE; Neogregarinorida: Ophryocystidae) was identified as a parasite of
 monarch (Danaus plexippus) and queen (D. gilippus) butterflies in the late
 1960s in Florida, USA. Recently, similar parasites were identified in
 other Danaus species, but their occurrence among the diverse clade of
 milkweed butterflies (Nymphalidae: Danainae) remains unexplored. This
 study used museum collections to systematically investigate the host range
 and global occurrence of OE and similar Ophryocystis parasites in milkweed
 butterflies. We examined 2,727 museum specimens from 86 countries/areas,
 spanning 61 milkweed butterfly species across 10 genera, to document
 parasitism. Our findings revealed that, among milkweed
 butterflies, Ophryocystis parasites were confined to hosts in the
 genus Danaus and were widespread across five continents. Positive
 specimens dated back to 1909. Lesser wanderers (D. petilia) exhibited the
 highest percentage of positive specimens (16%), followed by monarchs
 (12%), plain tigers (D. chrysippus, 11%), and queens (4%). We also present
 the first documented infections in Jamaican monarchs (D. cleophile, 4%).
 The patterns of parasite variation in size reflected the relatedness of
 their host species but not their size. Overall, this research underscores
 the value of museum collections for investigating geographic and temporal
 host-parasite associations and provides foundational ecological data on
 the relationships between Ophryocystis parasites and their milkweed
 butterfly hosts.
description: We used archived specimens to determine infection status and the
 temporal and geographic infection patterns among milkweed butterflies.
 Butterfly species targeted were milkweed butterflies in the subfamily
 Danainae. We recorded the specimen information from its label. Pictures of
 the dorsal side of each pinned specimen were taken. When no species
 information was included on the specimen’s label, pictures were used for
 identification. A subset of pictures alongside label information was
 shared with an expert on milkweed butterfly taxonomy for identification or
 confirmation. We followed Ackery and Vane-Wright (1984) to standardize the
 taxonomic nomenclature and resolve synonyms at the species level except
 where more recent taxonomic work was available. Specimens were swabed and
 screened for the presence of spores of <em>OE</em> and
 morphologically similar parasites. We used digital photographs to estimate
 the forewing length (mm) of a subset of parasite-positive and negative
 specimens. We also estimated the median spore size (two-dimensional area,
 µm2) for each positive butterfly measured.
description: # Museum collections reveal a global range of *Ophryocystis* parasites in
 *Danaus* butterflies
 [https://doi.org/10.5061/dryad.t76hdr88p](https://doi.org/10.5061/dryad.t76hdr88p) ## Description of the file structure Data and code to accompany the research article "Museum collections reveal a global range of *Ophryocystis* parasites in *Danaus* butterflies". All necessary files to perform the analysis are included. The code is written in the R language. | File | Description | | :-------------------------------------------------- | :------------------------------------------------------------------------------------------ | | Museums\_butterfly\_parasites\_data\_dictionary.csv | Data dictionary describing the variables for each of the three CSV data files included here | | museums\_butterfly\_parasites\_data.csv | Data for each museum specimen sampled, including infection results | | museums\_host\_data.csv | Host morphology data | | museums\_spore\_data.csv | Parasite morphology data | | museums\_butterfly\_parasites\_analysis.R | R code for data analysis; it uses the three CSV files provided |