About

Michael J. Skvarla is an Assistant Research Professor of Arthropod Identification at Penn State University. His duties include identifying insects and other arthropods submitted by the public, writing and maintaining entomology fact sheets, presenting science-based information to the public via seminars and workshops, and conducting limited original research. Since starting at Penn State in 2017, much of his research has been based on specimens submitted to the Insect Identification Laboratory. His research projects have included work on Sclerodermus wasps, which parasitize wood-boring beetles and can infest homes with beetle infestations, and European red-and-black melyrids, which are soft-winged flower beetles that can appear in homes during the spring.

Research topics

• Biology
• Computer Science
• Ecology
• World Wide Web
• Veterinary medicine
• Data science
• Zoology
• Geography
• Meteorology
• Library science

Selected publications

• A new species of Scutopalus (Acari: Cunaxidae: Cunaxoidinae) from Rio Grande do Sul State, Brazil with a key to world species

  The Catalogue of Life · 2026-02-16

  datasetOpen access
  PublisherDOI

• A new species of Scutopalus (Acari: Cunaxidae: Cunaxoidinae) from Rio Grande do Sul State, Brazil with a key to world species

  The Catalogue of Life · 2026-02-17

  datasetOpen access
  PublisherDOI

• New Records of Deer Keds (Diptera: Hippoboscidae: Lipoptena cervi L. and L. mazamae Rondani) in Eastern North America

  Proceedings of the Entomological Society of Washington · 2026-03-19

  article1st authorCorresponding

  Deer keds (Diptera: Hippoboscidae: Lipopteninae) are blood-feeding ectoparasitic flies that usually feed on deer and other Cervidae but sometimes bite humans. Two species are found in eastern North America: introduced European deer keds (Lipoptena cervi L.) and native Neotropical deer keds (L. mazamae Rondani). While historically dismissed as potential vectors of diseases, half a dozen tick-borne pathogens, including species pathogenic to humans, have been sequenced from deer keds over the last 15 years. In response to growing concerns that deer keds may transmit pathogens, efforts have been made recently to determine the distribution of deer keds in North America. Herein, we present new state records for Illinois, Kentucky, Michigan, and Nebraska, as well as 146 new county records from these and other states. We also discuss the relationship of hippoboscids to CO2-baited mosquito traps and review the impact of the community science platforms iNaturalist.org and BugGuide.net.

  PublisherDOI

• Documentation of a Periodical Cicada (Hemiptera: Cicadidae: Magicicada Davis) Biting a Human and the Subsequent Reaction

  Proceedings of the Entomological Society of Washington · 2026-01-29

  article1st authorCorresponding
  PublisherDOI

• World checklist of Cunaxidae

  The Catalogue of Life · 2026-02-16

  datasetOpen access1st authorCorresponding
  PublisherDOI

• Seasonal patterns of lotic water mite assemblages

  Acarologia · 2025-09-04

  articleOpen accessSenior author

  Despite their widespread diversity and abundance, water mites are understudied in many parts of the world. While previous literature has primarily emphasized taxonomy and distribution, several recent studies have found that water mite communities can be used as bioindicators of water quality conditions. Thus, there has been a push to explore strategies to incorporate them into global biomonitoring efforts. If the use of water mites as bioindicators is to become more widespread, it is important that we understand how seasonality influences their abundance in aquatic ecosystems. This study examines how populations of water mites in central Pennsylvania vary throughout the year. We sampled nine different sites every other month between August 2021 and August 2022. In total, we collected 8,471 individual water mites representing 14 genera, 9 families, and 5 superfamilies. Similar to studies conducted in Europe, our results indicate that while water mites can be collected year-round, abundance peaks in the summer between June and August, making this an ideal timeframe to focus collection efforts.

  PublisherDOI

• Water mites and their use as bioindicators of water quality conditions: a Pennsylvania case study

  Acarologia · 2024-01-18 · 7 citations

  articleOpen accessSenior author

  Water mites (Acariformes: Hydrachnidia) are one of the planet's most diverse and abundant groups of aquatic arthropods. With more than 7,500 described species, water mites have been documented in nearly every known freshwater environment. In lotic systems, water mites are commonly found in fast-flowing, riffle-run stream habitats, where one square meter of substrate can contain as many as 5,000 individual mites representing more than 50 species, 30 genera, and all 8 superfamilies. Despite their widespread distribution, relative diversity, and abundance, water mites have been widely neglected in freshwater biomonitoring efforts. However, several studies across the globe have found that water mites can be used as successful bioindicators of water quality conditions. Thus, the following study provides one of the first detailed examinations of lotic water mites and their bioindicator potential in North America. We sampled water mites from sites along 'attaining' (unpolluted) and agriculturally 'impaired' (polluted) riffle-run stream habitats and compared their assemblages to other physicochemical and benthic macroinvertebrate metrics used to quantify water quality in Pennsylvania. In total, we collected 9,139 individual water mites representing 5 superfamilies, 9 families, and 14 genera from both attaining (n = 13) and impaired (n = 13) streams. Similar to other global studies, we found significant differences between the water mite assemblages of attaining and impaired streams, with attaining streams having greater richness and diversity of water mites. Our data shows that several mite taxa are associated with biological and physicochemical conditions of water quality, where some known sensitive taxa are increasingly dominant in attaining streams and less dominant in impaired streams. Conversely, some pollution-tolerant taxa dominance increases in impaired streams while sensitive taxa abundance declines. These findings illustrate that water mites vary in their sensitivity to pollution and are suitable bioindicator species whose inclusion in biomonitoring assessments will increase assessment accuracy.

  PublisherDOI

• A survey of pesticide use in horticulturally-grown carnivorous plants, with a review of arthropod pests

  Carnivorous Plant Newsletter · 2024-05-02

  reviewOpen access1st author

  Arthropod pests are sometimes reported from horticulturally-grown carnivorous plants. While it is broadly known which pest groups are involved, little work has been done to characterize them specifically, which can be important when implementing control strategies. Pesticide recommendations are available through books and other media, but pesticides have not been systematically tested for phytotoxic effects in carnivorous plants so growers may worry about using them. In response to these issues, we conducted a survey of carnivorous plant growers to understand what pests they encounter, which pesticides they use, and if any of those pesticides have caused issues to the plants, the results of which are reported herein. We also provide a summary of different arthropod pests recorded from carnivorous plants in order to provide context for these pests and their control, and to encourage growers to document pests they encounter to fill in knowledge gaps.

  PublisherOA PDFDOI

• Insects visit <i>Fusarium xyrophilum</i> pseudoflowers on the host <i>Xyris surinamensis</i> (Xyridaceae) and carry fungal DNA on their bodies

  bioRxiv (Cold Spring Harbor Laboratory) · 2024-03-08

  preprintOpen access

  Abstract The fungus Fusarium xyrophilum produces flower-like structures (i.e., pseudoflowers) that were recently discovered on yellow-eyed grasses ( Xyris spp.) in Guyana. It is unknown whether these pseudoflowers, which are composed entirely of fungal tissue, are true mimics that attract insects as a means of fungal dispersal. We evaluated the potential of F. xyrophilum to affect insect visitation patterns to flowers and pseudoflowers by 1) documenting insect visitation to X. surinamensis in Guyana, 2) measuring the presence of F. xyrophilum DNA on insects, and 3) evaluating fluorescence and volatile production on flowers and pseudoflowers. We report for the first time Vespidae, Formicidae, Salticidae, Acrididae, and Tetrigidae visiting Xyris . Diverse insects, including Conocephalini spp. (meadow katydids; Tettigoniidae), Camponotus spp. (carpenter ants; Formicidae), and a Geometridae sp. (geometer moths) were found to visit flowers and pseudoflowers. Fusarium xyrophilum DNA was detected on 3/12 (25%) of captured insect bodies using conventional and quantitative PCR. Volatiles produced in the field by pseudoflowers and flowers were similar, except for the presence of a sesquiterpene, putatively identified here as α-gurjunene, which was detected both in F. xyrophilum pure cultures and field-collected pseudoflower samples, but not from flowers. The production of this sesquiterpene by F. xyrophilum and the fluorescence of X. surinamensis peduncles represent potential signals involved in insect attraction for this system. These observations, along with the overlap in insect visitors of flowers and pseudoflowers and the detection of F. xyrophilum DNA on insect bodies, are consistent with insect visitors being vectors of Xyris pollen and F. xyrophilum propagules between host plants.

  PublisherOA PDFDOI

• Diversity of Arthropods that Visit Xyris spp. (Xyridaceae): New Observations from Guyana

  Proceedings of the Entomological Society of Washington · 2024-01-31 · 3 citations

  articleSenior author

  Xyris spp., commonly known as yellow-eyed grasses, do not possess nectaries and were thought not to attract many insect visitors. The majority of insect visitation studies carried out on this genus have been limited to North American species, despite its center of diversity being in South America. The discovery of a potential new fungal mimicry system on Xyris spp. and the potential for insect visitation pattern alteration by the fungus led us to assess arthropod visitation to Xyris spp. in three regions of Guyana. Arthropods were photographed and identified morphologically. Here, we provide the first documentation of arthropods in the orders Araneae, Coleoptera, and Orthoptera visiting Xyris spp. plants. We also observed a Coleophora sp. (Lepidoptera: Coleophoridae) on Xyris spikes, expanding the geographic range of this taxon.

  PublisherDOI

Frequent coauthors

• Ashley P. G. Dowling

  University of Arkansas at Fayetteville

  40 shared

• J. Ray Fisher

  Mississippi State University

  20 shared

• Danielle M. Fisher

  University of Arkansas at Fayetteville

  18 shared

• Erika T. Machtinger

  Pennsylvania State University

  11 shared

• Gary L. Miller

  9 shared

• Gary R. Bauchan

  United States Department of Agriculture

  8 shared

• Scott A. Schneider

  Agricultural Research Service

  8 shared

• Ronald Ochoa

  United States Department of Agriculture

  8 shared

Education

• Postdoctoral researcher, Entomology

  University of Maryland

  2017

• PhD, Entomology

  University of Arkansas

  2015

• MS, Entomology

  University of Arkansas

  2011

• BS, Entomology

  Purdue University

  2008