Leaf-litter
Guides
Acropsopilio
harvestman
A genus of tiny harvestmen (Opiliones: Acropsopilionidae) established by Silvestri in 1904. The genus includes several species, with *Acropsopilio neozealandiae* being endemic to New Zealand where extensive collecting has yielded only female specimens, suggesting possible parthenogenetic reproduction. Members are found in forest habitats and are among the smallest harvestmen.
Aglaopteryx gemma
little gem cockroach
Aglaopteryx gemma is a small cockroach species in the family Ectobiidae, commonly known as the little gem cockroach. First described by Hebard in 1917, this species occurs in the southeastern United States and the Bahamas. It belongs to a genus of small, often inconspicuous cockroaches that inhabit leaf litter and ground-level vegetation.
Alaocybites
A genus of small, eyeless or microphthalmic weevils in the family Raymondionymidae. Originally described from California with two eyeless species, the genus was later discovered in the Russian Far East (Primorsky Kray) and represented by a fossil in Alaska. The genus is characterized by reduced or absent eyes and the absence of tarsomere IV on all legs, traits associated with edaphic (soil-dwelling) habits.
Aleocharinae
rove beetles
Aleocharinae is the largest subfamily of rove beetles (Staphylinidae), containing over 12,000 described species across more than 1,000 genera and 52 tribes. Members are predominantly small to minute beetles, typically 3–5 mm in length, with highly variable morphology reflecting their diverse ecological specializations. The subfamily exhibits extraordinary biological diversity, including free-living, myrmecophilous, termitophilous, parasitic, predatory, fungivorous, and herbivorous forms distributed across all terrestrial habitats worldwide.
Allacma fusca
Allacma fusca is a large springtail species endemic to western Continental Europe and the British Isles. Adults reach approximately 3.5 mm in length and inhabit moist terrestrial environments, particularly among leaf litter in surface soil layers. The species has been studied for its physiological tolerance to elevated carbon dioxide levels compared to deeper-soil springtails.
Amphasia interstitialis
Red-headed Ground Beetle
Amphasia interstitialis, commonly known as the red-headed ground beetle, is a small ground beetle native to North America. Adults measure 8.5–10.2 mm and display distinctive coloration with dark elytra contrasting against an orange pronotum and head. The species occupies moist, covered microhabitats within deciduous forests, including leaf litter and spaces beneath stones and logs. It is widespread across the northeastern United States and adjacent Canadian provinces, with populations extending into the central United States.
Anapidae
Ground Orb-web Spiders
Anapidae is a family of minute spiders containing approximately 233 extant species in 59 genera, with most adults measuring less than 2 mm in body length. The family has undergone significant taxonomic revision, incorporating the former families Micropholcommatidae and Holarchaeidae as subfamilies. Members are primarily ground-dwelling inhabitants of moist forest habitats, where many species construct diminutive orb webs less than 3 cm in diameter. The group exhibits remarkable anatomical conservation despite extreme miniaturization, retaining complete organ systems and musculature that comparable-sized insects often reduce or lose.
Anapistula
Anapistula is a genus of minute araneomorph spiders in the family Symphytognathidae, established by Gertsch in 1941. The genus comprises 28 described species distributed across tropical and subtropical regions of Asia, South America, and Europe. Members exhibit diverse habitat preferences: approximately 18 species occur in leaf litter, soil, and mosses, while seven are obligate cave-dwellers (troglobites) and one inhabits cave entrances. The genus includes some of the smallest spiders known, with A. ataecina from Portugal representing both the first European record of the family and one of the smallest described spider species.
Anasaitis canosa
Twin-flagged Jumping Spider
Anasaitis canosa is a small jumping spider in the family Salticidae, commonly known as the twin-flagged jumping spider. It is recognized by the paired white or pale flag-like markings on its dorsal abdomen, which give the species its common name. The species is native to the southeastern United States and has been introduced to Cuba. Like other salticids, it is an active visual hunter that does not build webs to capture prey.
Anthonomus quadrigibbus
apple curculio
Anthonomus quadrigibbus, commonly known as the apple curculio, is a small weevil species in the family Curculionidae. It is a fruit-feeding pest native to North America, primarily associated with rosaceous fruit trees and shrubs. Adults feed on developing fruits, causing significant damage, while larvae develop within the fruit, feeding on ovules. The species exhibits tight phenological synchronization with its host plants, with adult emergence and oviposition timed to specific flowering and fruit development stages.
Apheloria virginiensis reducta
Yellow-and-black millipede, Cyanide millipede
A large, colorful millipede in the family Xystodesmidae, distinguished by its black body with bright yellow or orange wedge-shaped posterolateral markings. Like other members of its genus, it produces hydrogen cyanide as a chemical defense, advertised by its conspicuous aposematic coloration. The subspecies represents a western population of A. virginiensis, with records extending from the Appalachian region through the Ozark Plateau to the Arkansas Delta.
Apomecynini
Apomecynini is a tribe of small, flightless (apterous) longhorn beetles within the subfamily Lamiinae. Members are commonly associated with leaf litter and subcortical habitats, particularly in the Neotropics. The tribe includes numerous species, many of which remain undescribed due to their cryptic lifestyle and small size.
Arcitalitrus
Lawn Shrimps, Beach Hoppers
Arcitalitrus is a genus of fully terrestrial amphipods commonly known as lawn shrimps or beach hoppers. The genus contains nine described species native to Australasia, with Arcitalitrus dorrieni and A. sylvaticus introduced to Europe and elsewhere through human activity. These crustaceans have adapted to life away from aquatic environments, inhabiting forest leaf litter and soil. Some species have become invasive outside their native range, spreading via the international plant trade.
Arianops nantahalae
Arianops nantahalae is a small rove beetle in the subfamily Pselaphinae, described by Barr in 1974. The species is endemic to the southern Appalachian Mountains of the eastern United States. It belongs to a genus of minute beetles adapted to life in forest leaf litter and soil microhabitats.
Arianops neglecta
Arianops neglecta is a species of rove beetle in the family Staphylinidae, subfamily Pselaphinae. It was described by Barr in 1974. The genus Arianops belongs to the tribe Amauropini within the diverse and species-rich pselaphine lineage. Members of this genus are small, cryptic beetles typically found in leaf litter and soil habitats. The specific epithet 'neglecta' suggests the species may have been overlooked or confused with related taxa prior to its formal description.
Atheta pennsylvanica
Atheta pennsylvanica is a species of rove beetle described by Bernhauer in 1907. It belongs to the large genus Atheta within the subfamily Aleocharinae. The species is known from eastern North America, with records spanning Canada and the northeastern United States. Like other aleocharine rove beetles, it is small-bodied and associated with soil and leaf litter habitats.
Atlanticus testaceus
protean shieldback, short-legged shield-bearer
Atlanticus testaceus, commonly called the protean shieldback or short-legged shield-bearer, is a shield-backed katydid native to eastern North America. The species exhibits pronounced sexual dimorphism in diet: adult females are primarily carnivorous while adult males consume mostly dried leaves and sand. Both sexes are known to engage in cannibalism. Activity is concentrated in the evening hours, with males stridulating intensively from elevated vegetation while females search for mates and prey.
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.
Batrisodes denticollis
Batrisodes denticollis is a species of ant-loving beetle in the family Staphylinidae, subfamily Pselaphinae. It is known from scattered localities across the eastern and central United States. Like other members of its genus, it is presumed to inhabit leaf litter and may associate with ants. The species was described by Casey in 1884.
Batrisodes riparius
Batrisodes riparius is a small rove beetle in the subfamily Pselaphinae, commonly known as short-winged mould beetles. It was described by Thomas Say in 1824, making it one of the earlier described species in the genus. Males of this species, like other Batrisodes, possess distinctive facial modifications including horns, spines, or other projections that give the genus its informal nickname "gargoyle beetles." The species occurs across eastern North America in leaf litter habitats.
Batrisodes scabriceps
gargoyle beetle
Batrisodes scabriceps is a small rove beetle in the subfamily Pselaphinae, commonly known as the short-winged mould beetles. Males of this species exhibit pronounced facial modifications including horns, spines, or other projections that give the genus its informal name 'gargoyle beetles.' The species was originally described by John Lawrence LeConte in 1849 and occurs across eastern and central North America. Like other members of Batrisodes, it is presumed to inhabit leaf litter and prey on microarthropods.
Batrisodes schaumii
Gargoyle beetle
Batrisodes schaumii is a species of rove beetle in the subfamily Pselaphinae, commonly referred to as a "gargoyle beetle" due to the distinctive facial ornamentation of males. The species was described by Aubé in 1844 and occurs across a broad range in the eastern and central United States. Like other members of its genus, it is presumed to inhabit leaf litter and prey on small arthropods such as mites and collembola.
Batrisodes striatus
Batrisodes striatus is a small rove beetle in the family Staphylinidae, subfamily Pselaphinae. It belongs to a diverse genus of minute beetles that inhabit leaf litter and soil environments. The species was originally described by John Lawrence LeConte in 1849 and is distributed across eastern and central North America.
Biphyllidae
False Skin Beetles
Biphyllidae, commonly known as false skin beetles, is a family of small beetles in the superfamily Cleroidea. The family contains approximately 195 described species distributed globally except New Zealand. Members are primarily found in concealed microhabitats including under bark of dead trees and in leaf litter. The family includes 11 extant genera plus one fossil genus from Late Cretaceous Taimyr amber.
Bolothrips bicolor
Bolothrips bicolor is a species of thrips in the family Phlaeothripidae, subfamily Idolothripinae. The species was first described by Heeger in 1852 under the name Phlaeothrips bicolor. It is a fungus-feeding thrips with a broad distribution spanning Europe, parts of Asia, and North America. The genus Bolothrips contains approximately 90 species worldwide, primarily associated with fungal spores in leaf litter and soil habitats.
Bothropolys
Bothropolys is a genus of lithobiid centipedes established by Wood in 1862. The genus comprises approximately 30 valid species distributed across North America and East Asia, with notable diversity in China. Species are primarily associated with temperate forest habitats, ranging from low elevations to montane environments above 2000 meters. Members of this genus are characterized by specific morphological traits including particular arrangements of ocelli, coxosternal teeth, and tergite projections.
Brachycepsis
Brachycepsis is a genus of minute rove beetles in the subfamily Scydmaeninae, established by Brendel in 1889. Members of this genus belong to the tribe Stenichnini, a group characterized by small body size and specialized ecological associations. The genus is part of the diverse Staphylinidae family, one of the largest beetle families. Limited species-level information is available in public databases.
Brachycybe petasata
Brachycybe petasata is a small millipede in the order Platydesmida, endemic to the southern Appalachian Mountains of the southeastern United States. It inhabits moist forest floor habitats, particularly leaf litter and decaying wood in beech, birch, maple, and hemlock forests. The species is distinguished by its production of four unique monoterpene alkaloids as chemical defenses: gosodesmine, hydrogosodesmine, homogosodesmine, and hydrohomogosodesmine. As a member of the subterclass Colobognatha, it represents one of the few millipede lineages known to synthesize terpenoid alkaloids.
Brachygluta
ant-loving beetles
Brachygluta is a genus of ant-loving beetles (Staphylinidae: Pselaphinae) containing over 80 described species. These small rove beetles are specialist predators of mites. The Nearctic fauna has been revised, with 29 species recognized in North America.
Brachygluta abdominalis
ant-loving beetle
Brachygluta abdominalis is a species of ant-loving beetle in the family Staphylinidae, subfamily Pselaphinae. It is found in North America, with records from Canada and the eastern United States. This species inhabits coastal ecosystems, specifically occurring in leaf litter of salt marshes, beaches, and other shoreline environments. The species has a problematic taxonomic history due to a missing type specimen, and its identity has been discussed but not fully resolved in recent revisions.
Brachygluta ulkei
Brachygluta ulkei is a small rove beetle in the subfamily Pselaphinae, a diverse group of minute beetles often associated with leaf litter and soil habitats. The species was described by Brendel in 1866 and occurs in the eastern United States. Like other pselaphines, it is likely a predator or scavenger in microarthropod communities, though specific ecological details remain poorly documented.
Brachypsectra fulva
Texas beetle
Brachypsectra fulva, commonly known as the Texas beetle, is a species in the family Brachypsectridae. Adults are rarely observed but are attracted to light and active from May to August. The larvae are predatory, living under bark, in leaf litter, and rock crevices, where they ambush small arthropod prey. The species occurs in the southwestern United States and Mexico.
Caccoplectus
Caccoplectus is a genus of myrmecophilous (ant-loving) rove beetles in the family Staphylinidae, subfamily Pselaphinae. The genus was established by Sharp in 1887 and contains approximately nine described species. These beetles are associated with ant colonies, a common ecological strategy among pselaphine beetles. Most species have been described from the Neotropical region, particularly Central America.
myrmecophileant-associatedpselaphinerove-beetleNeotropicalStaphylinidaePselaphinaeArhytodinitropicalant-colony-inhabitantinquilinemicrohabitat-specialistleaf-littersoil-dwellingcrypticrarely-collectedsmall-beetlemorphologically-specialized1887-descriptionSharpCentral-AmericaPanamaColeopteraPolyphagaStaphyliniformiaStaphylinoideaPselaphitaegenus-levelnine-speciesconicusdegallierilucidusnuttingipectinatusschwarzisentisspinipessucineasspine-legged-pselaphidChandlerWoldaSchaeffer190619761986type-species-unknownrarely-observediNaturalist:-2-observationsCatalogue-of-Life-acceptedGBIF-acceptedNCBI-acceptedEukaryotaMetazoaHexapodaInsectaArthropodaAnimaliabeetleinsectarthropodanimalCaddoidea
Caddoidea is a small superfamily of harvestmen (Opiliones) within the suborder Eupnoi, established by Nathan Banks in 1893. It contains two families: Caddidae and Acropsopilionidae. Members are characterized by distinctive morphological features including relatively long legs and compact bodies. The group has a disjunct distribution with representatives in North America, eastern Asia, and Australia. Caddoidea represents one of the more specialized lineages within the Dyspnoi-Eupnoi clade of long-legged harvestmen.
Carebara
Marauder Ants, Carebara Thief Ants
Carebara is a large genus of myrmicine ants comprising over 200 species distributed worldwide in tropical and Afrotropical regions. These ants are among the smallest known, with workers often barely visible to the naked eye. The genus exhibits remarkable worker polymorphism, including specialized soldier castes with phragmotic (door-blocking) head shapes in some African species. Queens are notably much larger than workers, creating one of the most extreme size dimorphisms in ants. Many species are cryptic inhabitants of soil and leaf litter, with poorly known biology.
Castianeira descripta
Red-spotted Ant-mimic Sac Spider, Redspotted Antmimic
Castianeira descripta is a small ant-mimicking spider in the family Corinnidae. It exhibits Batesian mimicry of ants, particularly carpenter ants, through body shape, coloration, and behavioral adaptations. The species is distributed across the United States and Canada.
Catalinus angustus
Catalinus angustus is a species of minute rove beetle in the family Staphylinidae, subfamily Scydmaeninae. These beetles are among the smallest staphylinids, typically associated with leaf litter and decaying organic matter in forested habitats. The genus Catalinus belongs to the tribe Stenichnini, a group characterized by their small size and specialized ecological roles in decomposition systems. Records indicate this species occurs in California, USA.
Ceratocanthus aeneus
shining ball scarab beetle, round fungus beetle
Ceratocanthus aeneus is a small pill scarab beetle in the family Hybosoridae, commonly known as the shining ball scarab beetle or round fungus beetle. The species is native to eastern and southeastern North America. Like other members of its subfamily, it exhibits a highly compact, rounded body form adapted for conglobation (rolling into a ball).
Ceratocombidae
minute litter bugs
Ceratocombidae is a family of minute litter bugs in the order Hemiptera, classified within the infraorder Dipsocoromorpha and superfamily Dipsocoroidea. The family comprises at least three genera—Astemma, Ceratocombus, and Leptonannus—with approximately 20 described species. Members are small, cryptic insects associated with decomposing organic matter in forest habitats. Their diversity is greatest in the Indo-Pacific region, though species occur across North America, Europe, Madagascar, and the Oriental region.
Choroterpes
Choroterpes is a genus of mayflies in the family Leptophlebiidae, distributed across the Americas, Europe (excluding the British Isles), Africa, and Asia. The genus contains multiple subgenera, including the nominate subgenus Choroterpes and Neochoroterpes (North America). Nymphs are typically found in streams and rivers, often associated with leaf litter. The genus has been subject to taxonomic revision, with some species reassigned to new genera such as Tikuna.
Chytonix sensilis
barrens chytonix
Chytonix sensilis, commonly known as the barrens chytonix, is a small noctuid moth native to eastern North America. First described in 1881, it is listed as endangered in Connecticut. The species is notable for its specialized larval diet of fungi growing on leaf litter and dead wood.
Corixidea
jumping soil bugs
Corixidea is a genus of small true bugs in the family Schizopteridae, commonly referred to as jumping soil bugs. The genus was established by Reuter in 1891 and contains at least three described species: C. crassa, C. lunigera, and C. major. These insects belong to the infraorder Dipsocoromorpha, a group of minute predatory or cryptozoic bugs associated with soil and leaf litter habitats. The genus is characterized by adaptations for jumping locomotion, though specific morphological details remain poorly documented in accessible literature.
Corixidea major
jumping soil bug
Corixidea major is a species of jumping soil bug in the family Schizopteridae, first described by McAtee and Malloch in 1925. It belongs to the infraorder Dipsocoromorpha, a group of small predatory true bugs. The species is known from North America. Like other schizopterids, it is associated with soil and leaf litter habitats.
Corythucha juglandis
Walnut Lace Bug
Corythucha juglandis, the walnut lace bug, is a univoltine or bivoltine lace bug (Hemiptera: Tingidae) native to North America and specialized on walnut (Juglans) host plants. Adults overwinter in leaf litter and become active in April or May, synchronizing with host leaf phenology. The species aggregates on the undersides of leaflets for feeding and reproduction. Both adults and nymphs are gregarious. It has been studied in Ontario, Québec, Canada, and southern Illinois, USA, with some geographic variation in voltinism reported.
Cossoninae
Cossoninae is a subfamily of true weevils within the family Curculionidae. Members of this subfamily are characterized by their small to medium size and association with woody substrates, including timber, leaf litter, and plant roots. The group exhibits considerable diversity in habitat preference, with species found in marine/coastal environments, forest leaf litter, and specialized niches such as sand dunes and the phloem of living trees. Many species possess reduced or absent eyes (anophthalmous or microphthalmous) and exhibit endogean or cryptic lifestyles. The subfamily includes both economically significant timber pests and ecologically important decomposers.
Crosbyella distincta
armoured harvestman
Crosbyella distincta is a species of armoured harvestman described by Goodnight & Goodnight in 1942. It belongs to the family Phalangodidae, a group of small to medium-sized harvestmen characterized by their heavily armored bodies. The species is known from North America. Armoured harvestmen in this family are typically found in leaf litter and soil habitats where they function as predators and scavengers.
Cryptocephalini
case-bearing leaf beetles
Cryptocephalini is a tribe of leaf beetles within the subfamily Cryptocephalinae, characterized by case-bearing larvae that construct and carry protective cases. The tribe comprises approximately 987–988 species in the Palaearctic region alone, with substantial diversity in arid and Mediterranean zones. Some species exhibit myrmecophilous associations with ants.
Cybaeus morosus
Morose Woodland Spider
Cybaeus morosus is a small woodland spider in the family Cybaeidae, first described by Eugène Simon in 1886. It belongs to the 'marronoid' clade, a group of spiders united by molecular phylogenetics rather than obvious morphological similarities. The species is known from forest floor habitats in North America, where it constructs sheet webs or retreats under debris. Like other Cybaeidae, it is a ground-dwelling spider that plays a role in leaf litter decomposition and nutrient cycling.
Cyphophthalmi
Mite Harvestmen
Cyphophthalmi is a suborder of harvestmen (Opiliones) comprising six families grouped into three infraorders: Boreophthalmi, Scopulophthalmi, and Sternophthalmi. Adults range from 1 to 7 mm in length with relatively short legs compared to other harvestmen. The suborder is characterized by unique morphological features including elevated cone-shaped ozophores, a spermatopositor instead of a true penis in males, and a completely open gonopore lacking a genital operculum. Many species are eyeless and inhabit leaf litter or caves. Cyphophthalmi represents one of two major lineages of harvestmen, with the other lineage (Phalangida) containing Laniatores, Dyspnoi, and Eupnoi.
Dasycerus carolinensis
Dasycerus carolinensis is a flightless rove beetle endemic to the southern Appalachian Mountains of eastern North America. Phylogeographic studies reveal deep genetic divergence between populations east and west of the French Broad River, with divergence estimated at approximately 5.8 million years ago. The species inhabits forest leaf litter and shows evidence of cryptic differentiation across its range. Despite being flightless, it has persisted across both old-growth forest fragments and secondary growth forests.