Aptery

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
Colaspidea
Colaspidea is a genus of leaf beetles in the subfamily Eumolpinae. The genus exhibits a disjunct distribution, occurring in the Mediterranean region and in western North America (California and the southwestern United States). A notable morphological distinction exists between regional species: North American species possess fully developed wings, while Mediterranean species are wingless. Recent phylogenetic hypotheses suggest that Mediterranean Colaspidea may be sister to Chalcosicya, with Colaspina sister to both combined; North American species may represent a separate genus. The genus currently contains 19 described species.
leaf-beetle Eumolpinae Chrysomelidae disjunct-distribution wing-dimorphism aptery Mediterranean North-America California phylogenetic-uncertainty
Cysteodemus armatus
inflated beetle, inflated blister beetle
Cysteodemus armatus is a flightless blister beetle in the family Meloidae, distinguished by its dramatically inflated elytra that form a rounded, dome-like covering. The species occurs in arid and semi-arid regions of southwestern North America and Central America. Its fused wing covers render it incapable of flight, an unusual trait among beetles. The beetle's distinctive appearance and defensive chemistry align with typical meloid characteristics, though specific ecological details remain poorly documented.
flightless desert blister-beetle inflated-elytra aptery
Dipara
Dipara is a genus of minute parasitoid wasps in the family Diparidae (Chalcidoidea), first described by Walker in 1833. The genus exhibits pronounced sexual dimorphism: females are typically wingless (apterous) or short-winged (brachypterous) with clavate antennae, while males are fully winged (macropterous) with filiform antennae. Species are collected primarily from leaf litter and soil habitats using yellow pan traps. Despite flightless females suggesting limited dispersal, some species show minimal phylogeographic structure across broad geographic ranges.
parasitoid sexual-dimorphism aptery leaf-litter soil-fauna Chalcidoidea wing-polymorphism
Floritettix aptera
Wingless Florida Grasshopper
Floritettix aptera, commonly known as the wingless Florida grasshopper, is a species of spur-throated grasshopper in the family Acrididae. The specific epithet "aptera" refers to its wingless condition, a distinctive trait among grasshoppers. The species is endemic to Florida and belongs to the genus Floritettix, which is part of the diverse Melanoplinae subfamily.
grasshopper Orthoptera Acrididae Melanoplinae wingless aptery Florida-endemic spur-throated flightless
Georissidae
minute mud-loving beetles
Georissidae is a small family of beetles commonly known as minute mud-loving beetles, containing the single genus Georissus. Members are tiny insects typically found in wet soil and riparian environments near water. Some species have been documented in atypical habitats such as cloud forest leaf litter. The family exhibits notable morphological and behavioral diversity, including psammophory (sand adherence for camouflage) in some subgenera and aptery (winglessness) in certain species.
Hydrophiloidea psammophory aptery riparian soil-dwelling camouflage
Georissus
minute mud-loving beetles
Georissus is the sole genus in the family Georissidae, comprising approximately 75 described species of minute beetles. Members are distinguished by their habit of psammophory—actively covering their elytra with sand or mud particles as a defensive adaptation. The genus exhibits notable ecological flexibility, with most species inhabiting riparian mud and sand, while some populations occupy tropical rainforest leaf litter and cloud forest terrestrial habitats. The genus is divided into three subgenera: Georissus, Neogeorissus, and Nipponogeorissus.
psammophory aptery riparian leaf-litter Hydrophiloidea
Lagriinae
Long-jointed Beetles
Lagriinae is a subfamily of darkling beetles within the family Tenebrionidae, comprising more than 270 genera grouped into 11 tribes. Adults are medium-sized (5–12 mm) with characteristic Tenebrionidae features including a 5-5-4 tarsal formula and antennal bases concealed by canthi. The subfamily is notable for its defensive symbiosis with Burkholderia bacteria that produce the antifungal compound lagriamide, protecting eggs and larvae from antagonistic fungi. This symbiosis has evolved through multiple independent horizontal acquisition events rather than strict co-diversification.
defensive-symbiosis Burkholderia lagriamide genome-erosion horizontal-transmission mimicry sexual-dimorphism aptery darkling-beetles Tenebrionidae Coleoptera mutualism fungal-defense ovipositor-glands
Stenopodainae
Stenopodainae is a subfamily of assassin bugs (Reduviidae) containing approximately 113 genera and ~770 species worldwide. Members are predominantly tropical, with many species associated with soil or sand substrates. The subfamily is characterized by distinctive morphological features including prominent mandibular plates and a modified antennal structure. Many species exhibit wing reduction (aptery) and cryptic coloration. Some species have been observed to use plant-derived resin on their forelegs to aid in prey capture.
assassin-bug Reduviidae predatory cryptic-coloration aptery resin-use tropical soil-dwelling
Tychobythinus
Tychobythinus is a genus of small rove beetles in the subfamily Pselaphinae (Staphylinidae). The genus is widely distributed across the Palearctic region, including North Africa, southern and Central Europe, the Caucasus, Japan, far eastern Russia, and southeastern China. Several species exhibit troglobitic adaptations, including reduced pigmentation, microphthalmia, winglessness, and elongated appendages. The genus contains at least 44 species and subspecies in Italy alone, with ongoing taxonomic revisions clarifying species boundaries and synonymies.
rove-beetle pselaphine cave-beetle troglobite Palearctic endemic gypsum-karst microphthalmia aptery Staphylinidae Sicily Italy North-Africa taxonomic-revision