Genitalia-identification

Guides

Allocapnia rickeri
Midwest Snowfly
Allocapnia rickeri is a small winter stonefly in the family Capniidae, commonly known as the Midwest Snowfly. It is one of numerous small, dark stoneflies in the genus Allocapnia that emerge during cold months when few other insects are active. The species has been documented across the central and eastern United States. Like other capniids, it is associated with clean, cold streams and is an important indicator of water quality.
winter-stonefly bioindicator coldwater Plecoptera Capniidae Allocapnia lotic emergence brachyptery aptery genitalia-identification Frison-1942 Midwest southeastern-US clean-water-indicator January-March small-stonefly wingless-female stream-insect shredder gatherer seasonal-resource water-quality aquatic-insect terrestrial-adult short-lived-adult oviposition submerged-eggs high-dissolved-oxygen low-temperature central-US eastern-US Alabama Arkansas Delaware Georgia Illinois hexapod hemimetabolous Euholognatha Nemouroidea Arctoperlaria Insecta Arthropoda Animalia GBIF Catalogue-of-Life iNaturalist NCBI taxonomy accepted-species 1942 Frison Ricker Midwest-Snowfly snowfly small-dark-stonefly clean-streams rivers well-oxygenated lotic-habitat cold-months winter-activity wing-reduction female-aptery male-flight epiproct paraproct terminalia taxonomic-revision congeners distribution-records observations 9-observations eukaryote metazoan arthropod insect stonefly winter-emerging January February March cold-weather near-freezing below-freezing water-surface submerged-substrates allochthonous-organic-material stream-ecosystems seasonal-food-resource insectivorous-birds predators scarce-prey unpolluted no-economic-importance stream-monitoring water-quality-indicator high-quality-coldwater microscopic-examination taxonomic-keys male-terminalia reliable-separation genitalic-examination overlapping-distribution similar-habitat small-size under-10-mm body-length reduced-wings absent-wings fully-developed-wings specific-identification published-descriptions illustrations subsequent-revisions characteristic family-Capniidae common-name extended-nymphal-period one-to-two-years short-lived does-not-feed aquatic-nymph clean-cold-streams low-temperatures year-round winter-months January-through-March family centered-Midwest extends-southeastern United-States documented appears most-reliably distinguished subtle-differences terminal-abdominal-structures should-be-compared against published subsequent genus-level characterized reduced absent females fully-developed males requires-examination male-genitalia structure paraprocts reliable separation overlaps similar many externally definitive relies microscopic examination comparison keys used biological indicator programs presence indicates cold conditions no-direct economic importance shredders gatherers processing allochthonous organic material stream ecosystems seasonal food resource insectivorous birds other when alternative prey scarce serves high-quality habitats development aquatic nymphal stages terrestrial adult stage nymphs develop streams extended period likely one two years based related species adults do-not feed active during weather air temperatures may near below freezing winged capable flight wingless short-winged remain water surface mating occur winter entering deposit eggs submerged substrates small commonly known numerous dark emerge few insects central eastern associated clean important under mm body length members genus wings possess fully developed specific identification level within requires male genitalia particularly most reliably subtle differences these terminal abdominal structures should compared descriptions taxonomic revisions winter-emerging maintain low high dissolved oxygen levels throughout year United States distribution centered extends southeastern months typically through this activity gives rise common name do not provides quality monitoring no direct habitat morphology size genitalic
Asaphocrita aphidiella-complex
Asaphocrita aphidiella-complex is a species complex within the family Blastobasidae, a group of small moths often associated with stored products and plant materials. Species in this complex are morphologically similar and have been historically confused, requiring detailed examination for accurate identification. They are part of a genus known for diverse larval habits including predation, parasitism, and detritivory. The complex designation indicates ongoing taxonomic uncertainty regarding species boundaries.
Blastobasidae stored-product-pest taxonomic-complex genitalia-identification North-America small-moth Lepidoptera
Bathyphantes canadensis
Canada Sheetweb Weaver
Bathyphantes canadensis is a small sheetweb weaving spider in the family Linyphiidae, found across northern North America and eastern Russia. It is one of approximately 4,000 species in the sheetweb weaver family, characterized by their flat, horizontal web architecture. The species is rarely encountered by casual observers due to its small size and cryptic habits.
Linyphiidae sheetweb-weaver spider North-America Russia Araneae enteleynae genitalia-identification Emerton-1882
Batrisodes
gargoyle beetle, ant-loving beetle
Batrisodes is a genus of myrmecophilous rove beetles in the family Staphylinidae, subfamily Pselaphinae. The genus contains at least 80 described species distributed across North America, Europe, and Asia. Males of many species exhibit highly modified facial structures with horns, spines, shelves, or cavities, earning the group the informal name 'gargoyle beetles.' Species are primarily associated with ants, though specific ecological relationships remain poorly documented for most taxa.
myrmecophilous Pselaphinae rove-beetle leaf-litter male-dimorphism genitalia-identification
Callilepis gertschi
Callilepis gertschi is a ground spider in the family Gnaphosidae, described by Platnick in 1975. Like other members of its genus, it possesses ornate coloration and cylindrical spinnerets characteristic of gnaphosids. The genus Callilepis is noted for being morphologically similar to the colorful genus Sergiolus, with separation requiring examination of genitalia. Very few observations of this species have been recorded.
ground-spider gnaphosidae ornate cylindrical-spinnerets genitalia-identification platnick-1975
Crambinae
Grass-veneers and Allies, snout moth grass borers, sod webworms
Crambinae is a large subfamily of Crambidae moths comprising over 1,800 species worldwide. Members are commonly known as snout moths, grass-veneers, or sod webworms. The subfamily is characterized by specialized morphological features including tympanal organs and a phallus attached medially to the juxta. Larvae are primarily root feeders or stem borers on grasses, with several species recognized as significant agricultural pests of maize, sugarcane, rice, and turfgrasses.
Lepidoptera Crambidae grass-moths agricultural-pests stem-borers root-feeders snout-moths sod-webworms brachyptery genitalia-identification
Dolichopus eudactylus
Dolichopus eudactylus is a species of long-legged fly in the family Dolichopodidae, first described by Loew in 1861. As a member of the genus Dolichopus, it belongs to a diverse group of small predatory flies characterized by elongated legs and often metallic coloration. The species is part of a family with approximately 1,300 species in North America north of Mexico alone. Like other dolichopodids, D. eudactylus is predatory on small insects and is typically found in sunny, open habitats.
predator aquatic-surface metallic fast-moving genitalia-identification
Eupitheciini
Pug Moths, Pugs
Eupitheciini is a tribe of geometer moths in the subfamily Larentiinae, commonly known as pugs. With approximately 1,900 described species distributed across 47 genera, it is the most species-rich tribe in the family Geometridae. The genus Eupithecia alone contains roughly 1,400 species and is one of the largest insect genera globally. Members are typically small moths with narrow wings and cryptic coloration. Identification relies heavily on genitalia dissection due to morphological homogeneity among species.
geometer-moths Larentiinae pugs cryptic-species species-rich genitalia-identification global-distribution
Glaucolepis saccharella
Glaucolepis saccharella is a minute moth in the family Nepticulidae, one of the smallest moth families by body size. The species was originally described as Nepticula saccharella by Braun in 1912 and later transferred to Glaucolepis. It belongs to a genus of leaf-mining moths whose larvae feed internally on plant tissue. The species has been documented in the eastern United States.
leaf-miner microlepidoptera Nepticulidae Nearctic genitalia-identification
Petrophila fulicalis
Feather-edged Petrophila
Petrophila fulicalis is a crambid moth described by James Brackenridge Clemens in 1860. It belongs to a species group that has been taxonomically clarified using citizen science data, distinguishing it from similar species P. confusalis and P. bella. Adults are diurnal and often found near running water. The species has a broad North American distribution with two distinct population centers: eastern records from the Great Lakes and Appalachian regions, and western records from the southwestern United States and northern Mexico.
aquatic-moth diurnal running-water citizen-science genitalia-identification
Xysticus
Ground Crab Spiders
Xysticus is a large genus of approximately 275–300 species of ground crab spiders in the family Thomisidae. These spiders are ambush predators that do not build webs, instead hunting near the ground by seizing prey with their enlarged anterior legs. The genus exhibits strong sexual dimorphism, with females typically reaching 10 mm in body length while males are roughly half that size. Species identification requires microscopic examination of genitalia due to the morphological similarity among members of the genus.
spider crab-spider ambush-predator ballooning subsocial-behavior biological-control sexual-dimorphism genitalia-identification ground-dwelling Thomisidae