Nocturnal
Guides
Antrodiaetus pacificus
Pacific Foldingdoor Spider
Antrodiaetus pacificus is a mygalomorph spider native to the Pacific Northwest of North America, ranging from San Francisco Bay to Alaska. It is the northernmost mygalomorph spider on the continent. The species was first described by Eugène Louis Simon in 1884 under the name Brachybothrium pacificum. It constructs burrows in soft substrates and exhibits year-round activity with peak mating season between early June and late November.
Anuroctonus
Swollenstinger Scorpions, California Swollen-stinger Scorpions
Anuroctonus is a genus of scorpions in the family Chactidae, commonly known as swollenstinger scorpions. The genus is characterized by a distinctive swollen region on the telson just before the stinger, particularly prominent in mature males. The best-known species, Anuroctonus pococki, occurs in the coastal ranges of Southern California and Baja California. These scorpions are nocturnal ambush predators that construct burrows and are noted for their relatively large size compared to regional congeners.
Anuroctonus pococki
California Swollenstinger Scorpion, California swollen-stinger scorpion
Anuroctonus pococki is a large scorpion species reaching 65 mm in length, distinguished by a swollen region on the telson just before the stinger—most prominent in mature males—and large black-tipped pedipalps. Native to the Coast Ranges of Southern California and Baja California, it is the only member of its genus found in Baja California. First described in 2004, this nocturnal ambush predator constructs burrows and exhibits mildly venomous stings that are typically painful but non-serious.
Anurogryllus arboreus
Common Short-tailed Cricket, Arboreal Short-tailed Cricket
Anurogryllus arboreus is a burrowing cricket native to the southern and southeastern United States. Adults are pale brown with vestigial ovipositors and shed their wings shortly after maturation, becoming permanently flightless. Males call from elevated perches at night to attract females. The species was separated from the widespread Anurogryllus muticus in 1973 based on male calling behavior and morphological differences.
Anyphaena aperta
ghost spider
Anyphaena aperta is a species of ghost spider in the family Anyphaenidae, first described by Nathan Banks in 1921. The species is native to North America and has been documented in both the United States and Canada. It has been observed utilizing Australian tea tree plants (Leptospermum species) as habitat, representing an adaptation to an invasive plant species in its range. Ghost spiders in this family are generally nocturnal hunters that do not build webs to capture prey.
Anyphaena celer
ghost spider
Anyphaena celer is a species of ghost spider (family Anyphaenidae) native to North America. It is one of 32 previously described species in the species-rich celer group within the genus Anyphaena. The species was originally described as Clubiona celer by Hentz in 1847. Like other anyphaenids, it is nocturnally active and associated with vegetation.
Anyphaena dixiana
ghost spider
Anyphaena dixiana is a species of ghost spider in the family Anyphaenidae. It belongs to the celer species group within the genus Anyphaena. Originally described from the United States, the species has subsequently been recorded from Mexico. As with other anyphaenids, it is likely nocturnally active.
Anyphaena fraterna
ghost spider
Anyphaena fraterna is a species of ghost spider in the family Anyphaenidae, first described by Banks in 1896. It belongs to a family of wandering hunters that do not build permanent webs for prey capture. The species is documented from the United States, though specific details about its ecology and behavior remain limited in published literature. Like other anyphaenids, it is presumably nocturnally active and associated with vegetation.
Apamea burgessi ona
A subspecies of cutworm moth in the family Noctuidae, distributed in the North American Great Plains. The nominate subspecies Apamea burgessi burgessi occurs in the eastern portion of the range, while A. burgessi ona occupies more western localities. Like other members of the genus Apamea, it is nocturnal and attracted to light sources. The species complex presents identification challenges due to individual variation and overlapping morphological traits with related taxa.
Apamea devastator
glassy cutworm moth, glassy cutworm
Apamea devastator, commonly known as the glassy cutworm moth, is a noctuid moth of northeastern North America. The adult has a wingspan of 35–40 mm and flies from May to September. The larva is a subterranean cutworm that feeds on grasses, attacking roots and basal stems. The species is economically significant as a pest of turfgrass and agricultural grasses.
Apamea impulsa
Impulsive Apamea
Apamea impulsa, commonly known as the Impulsive Apamea, is a noctuid moth native to North America with a transcontinental distribution across southern Canada and the northern United States. The species has a wingspan of approximately 34 mm and exhibits univoltine life history with adults active during summer months. Larvae are grass-feeders, placing this species within the cutworm moth group whose members can be challenging to identify due to intraspecific variation and interspecific similarity.
Apamea niveivenosa
Snowy-veined Apamea Moth
Apamea niveivenosa, known as the snowy-veined apamea, is a noctuid moth native to northern North America. The species was first described by Grote in 1879. Its larvae are subterranean cutworms that feed on grasses and have been documented as pests of grain crops in interior North America. The species occurs across Canada and extends south to California.
Apamea quinteri
Quinter's Cutworm Moth
Apamea quinteri is a species of cutworm moth in the family Noctuidae, first described by Mikkola and Lafontaine in 2009. It belongs to a genus of moths notorious among lepidopterists for being difficult to identify due to individual variation and overlapping morphological features with congeners. The species is known from North America. Like other Apamea species, it is nocturnal and attracted to artificial light sources.
Apamea remissa
Dusky Brocade
Apamea remissa, commonly known as the dusky brocade, is a noctuid moth species with a wingspan of 36–42 mm. It occurs across the Palearctic region from Europe through Siberia to Japan, with disjunct populations in Alaska. The species exhibits considerable variation in wing markings, making identification challenging in some forms.
Apamea sora
Apamea sora is a nocturnal moth in the family Noctuidae found in western North America. The species exhibits considerable color variation, with forewings ranging from orange and ochre to gray, gray-violet, and black. It inhabits high-elevation spruce-fir forests and mid-elevation ponderosa pine forests of the Rocky Mountains and Pacific Northwest. The species was formerly treated as a subspecies of Apamea auranticolor but is now recognized as distinct.
Apamea unanimis
Small Clouded Brindle
Apamea unanimis, commonly known as the small clouded brindle, is a noctuid moth first described by Jacob Hübner in 1813. Native to Europe, Turkey, Azerbaijan, and western Siberia, it has been introduced to North America and is established in parts of Canada and the northern United States. The species is associated with wetland habitats where its larval host plants grow.
Apantesis
tiger moths
Apantesis is a genus of tiger moths in the family Erebidae, first described by Francis Walker in 1855. Following phylogenetic research published in 2016, the genera Grammia, Holarctia, and Notarctia were merged into Apantesis, substantially expanding its species diversity. The genus is found in North and Central America, with some species documented in other regions including Iraq. Members are characterized by bold color patterns typical of tiger moths, including striped forewings and often brightly colored abdomens that serve as aposematic signals.
Apantesis allectans
Apantesis allectans is a small tiger moth in the family Erebidae, originally described as Grammia allectans by Douglas C. Ferguson in 1985. The species was later transferred to Apantesis as part of a broader reclassification of tiger moth genera. It has a restricted distribution in the southwestern United States and northwestern Mexico, where it inhabits montane pine forests at moderate elevations.
Apantesis carlotta-nais-phalerata-vittata
A tiger moth species complex in the genus Apantesis, characterized by striking black-and-white striped forewing patterns typical of the group. Adults are nocturnal and attracted to light. The taxonomic status of this entity as a distinct species versus a species complex remains unresolved, reflecting ongoing taxonomic revision within the genus.
Apantesis incorrupta
Immaculate Tiger Moth
Apantesis incorrupta is an arctiine tiger moth in the family Erebidae, described by Henry Edwards in 1881. It occurs across the southwestern United States and Mexico, inhabiting grasslands and open woodlands. The species produces two generations annually and is notable for research demonstrating larval self-medication behavior using alkaloid compounds to combat parasitoids. It was transferred from the genus Grammia to Apantesis in recent taxonomic revisions.
Apantesis ornata
Ornate Tiger Moth, Achaia Moth
Apantesis ornata is a tiger moth in the family Erebidae, originally described by Packard in 1864 under the name Callarctia ornata. The species was long classified in the genus Grammia before being transferred to Apantesis in a 2016 revision that consolidated several related genera. It occurs across western North America from southern British Columbia to southern California and eastward to the Rocky Mountain states. Adults are active during summer months and are attracted to light. The species exhibits the bright warning coloration typical of tiger moths, though specific details of its biology remain incompletely documented.
Apantesis parthenice
Parthenice Tiger Moth
The Parthenice Tiger Moth is a nocturnal tiger moth in the family Erebidae, found across eastern North America from southeastern Canada through the eastern United States. Adults are active from June through late September and are readily attracted to artificial light sources. The species is common in open habitats including fields and woodland edges.
Apantesis quenseli
Labrador Tiger Moth
Apantesis quenseli, the Labrador tiger moth, is a species of tiger moth in the family Erebidae. It inhabits high-altitude alpine environments and polar regions across the Northern Hemisphere. The species was transferred from the genus Grammia to Apantesis in 2016, reflecting revised understanding of tiger moth phylogeny. Multiple subspecies have been described across its broad geographic range.
Apantesis virguncula
Little Virgin Tiger Moth
Apantesis virguncula, commonly known as the Little Virgin Tiger Moth, is a tiger moth in the family Erebidae. The species was originally described by W. Kirby in 1837 under the name Callimorpha virguncula, and has undergone several taxonomic revisions, most recently being transferred from the genus Grammia to Apantesis. It is widely distributed across southern Canada and the United States, with adults active primarily from mid-June to late July. The larvae feed on various herbaceous plants, particularly members of the family Asteraceae.
Apantesis vittata
Banded Tiger Moth
Apantesis vittata, commonly known as the banded tiger moth, is a tiger moth in the family Erebidae described by Johan Christian Fabricius in 1787. It occurs in the southeastern and mid-Atlantic United States, with adults active from early spring through autumn. The species has a wingspan of 32–42 mm and larvae feed on various herbaceous plants including dandelions.
Apatides
horned powder-post beetles
Apatides is a genus of beetles in the family Bostrichidae, commonly referred to as horned powder-post beetles. The genus was established by Casey in 1898 and contains at least four described species, including Apatides fortis, A. pollens, A. puncticeps, and A. robustus. Members of this genus are wood-boring beetles that have been documented in western Texas and neighboring regions, where they are attracted to ultraviolet light sources.
Apatides fortis
Apatides fortis is a species of bostrichid beetle (family Bostrichidae), a group commonly known as false powderpost beetles or branch borers. The species was described by LeConte in 1866 and occurs in North America. Based on field observations, adults have been attracted to ultraviolet light at night in sand dune habitats of western Texas. The genus Apatides includes wood-boring beetles whose larvae typically develop in dead or dying woody material.
Aphidoletes aphidimyza
aphid midge
Aphidoletes aphidimyza is a predatory gall midge used worldwide in biological control programs against aphids. Adults are small, delicate, nocturnal flies that feed on aphid honeydew and hide beneath leaves during daylight. The bright orange, slug-like larvae are specialized aphid predators that paralyze prey by injecting venom into leg joints before consuming body contents. The species is commercially mass-produced and distributed as pupae in moist substrate for greenhouse applications.
Aphonopelma gabeli
Chiricahuan Gray Tarantula
Aphonopelma gabeli is a medium-sized tarantula species in the family Theraphosidae, native to the Chihuahuan Desert region of the southwestern United States. It is commonly known as the Chiricahuan Gray Tarantula due to its occurrence in the Chiricahua Mountains area of southeastern Arizona and adjacent regions. The species was described by Andrew M. Smith in 1995 and is considered less commonly encountered than the sympatric Texas brown tarantula (Aphonopelma hentzi).
Aphonopelma steindachneri
Steindachner's Ebony Tarantula
Aphonopelma steindachneri, commonly known as Steindachner's Ebony Tarantula, is a New World terrestrial tarantula native to arid regions of California and Baja California, Mexico. The species reaches 12–13 cm in diagonal leg span and exhibits dark velvet black to deep brown coloration. It constructs and occupies burrows in open ground, emerging primarily at night to forage. Males become most visible during summer and fall breeding seasons when they leave burrows to search for mates. The species faces predation from spider wasps, centipedes, scorpions, and solifugids.
Aphrophora maculosa
Conifer spittlebug
Aphrophora maculosa is a species of spittlebug in the family Aphrophoridae, described by Doering in 1941. It belongs to a genus commonly known as conifer spittlebugs, many of which feed on coniferous trees. The species is found in western North America, ranging from British Columbia and Alberta in Canada south through Washington, Oregon, and California in the United States. Like other Aphrophora species, it is attracted to lights at night.
Aphrophora quadrinotata
four-spotted spittlebug
Aphrophora quadrinotata, commonly known as the four-spotted spittlebug, is a species of spittlebug in the family Aphrophoridae. It is found in North America. The species was described by Thomas Say in 1830. Like other spittlebugs, it is associated with coniferous habitats and produces the characteristic frothy spittle as nymphs.
Apoda latomia
Yellow-collared slug moth
Apoda latomia is a slug moth in the family Limacodidae. The species is known for its distinctive caterpillar that feeds on hickory foliage and has a helmet-like appearance. Adults are small, relatively nondescript moths. The species occurs in eastern North America and is most frequently encountered in its larval stage.
Apoda rectilinea
Rectilinea Slug Moth
Apoda rectilinea is a slug moth in the family Limacodidae, native to North America. The caterpillars are known for their distinctive flattened, slug-like form and are associated with oak foliage. Adults are small, relatively plain moths that are attracted to light. The species is part of a genus whose larvae feed on specific host plants and possess stinging spines.
Apoda y-inversum
inverted Y slug moth, yellow-collared slug moth
Apoda y-inversum is a slug moth in the family Limacodidae, known for its distinctive helmet-shaped caterpillar that feeds on hickory leaves. The species ranges across eastern North America from Quebec to Florida. Adults are active from May through August and have a wingspan of 21–30 mm. The common name refers to the yellow collar marking on the adult moth.
Apomyelois bistriatella
Heath Knot-horn
A small pyralid moth (wingspan 15–25 mm) with a circumpolar distribution across North America and northern Eurasia. Adults are active from May to September, with peak flight in June–July. Larvae are specialized fungivores that develop within Daldinia and Hypoxylon fungi growing on burnt or dead woody plants, particularly gorse and birch. Colonies are ephemeral and shift location based on the availability of suitable host fungi.
Araneus cavaticus
Barn Spider, Barn Orbweaver
Araneus cavaticus, commonly known as the barn spider, is a large orb-weaving spider native to North America. Females reach approximately 20 mm in body length and are typically yellow and brown in coloration. The species is strongly associated with human structures, particularly barns and wooden buildings, where they construct their webs in rafters and under eaves. The barn spider gained cultural significance as the basis for the character Charlotte in E. B. White's children's novel Charlotte's Web.
Araneus gemmoides
cat-faced spider, jewel spider
Araneus gemmoides is a common North American orb-weaver spider found in Canada and the United States. Adults are recognized by two prominent horn-shaped projections on the abdomen that create a cat-faced appearance. Females are considerably larger than males and die shortly after producing a single egg sac. The species builds vertical orb-webs near artificial lights and building exteriors, where it captures flying insects at night while hiding in a retreat during the day.
Araneus pegnia
Butterfly Orbweaver
Araneus pegnia is a small orb-weaving spider in the family Araneidae, commonly known as the Butterfly Orbweaver due to the distinctive butterfly-shaped pattern on its abdomen. It is among the smaller members of the genus Araneus, with mature females reaching only 3.5–8.2 mm and males 2.5–5 mm. The species has an unusually broad geographic range, extending from the northeastern United States through the southeastern states, west to Arizona and California, and south through Middle America to Ecuador. It is also found on Caribbean islands including Jamaica, the Bahamas, and Cuba.
Arctosa littoralis
beach wolf spider, shoreline wolf spider
Arctosa littoralis, commonly known as the beach wolf spider or shoreline wolf spider, is a species of wolf spider in the family Lycosidae. It is a medium-sized spider (11-15 mm body length) with highly effective camouflage coloration adapted to sandy habitats. The species ranges throughout North and Central America, where it inhabits beaches, dunes, stream banks, and other sandy environments. It is primarily nocturnal and can be located at night by the distinctive blue-green eyeshine produced when light reflects from its tapetum lucidum.
Arctosa sanctaerosae
Santa Rosa Wolf Spider
Arctosa sanctaerosae is a wolf spider endemic to the secondary dunes of white sandy beaches along the Northern Gulf Coast of the United States. The species is nocturnal and burrow-dwelling, with discrete generations. It has experienced significant habitat degradation and fragmentation due to coastal development and tourism over the last century, resulting in reduced gene flow and smaller effective population sizes across five identified population clusters. Hurricanes pose additional natural disturbance, with population recovery influenced by dune height and vegetation density.
Arenaeus cribrarius
Speckled Swimming Crab
Arenaeus cribrarius, the speckled swimming crab, is a portunid crab distributed throughout the western Atlantic from Massachusetts to Argentina. It inhabits shallow sandy substrates but occurs to depths of 61 m, burying itself in sediment while maintaining respiratory water flow through a maintained gap. The species exhibits nocturnal, solitary behavior and is an opportunistic feeder that ambushes prey from its buried position. It supports commercial fisheries, particularly along the Brazilian coast, and has demonstrated reproductive plasticity in response to population pressures.
Arethaea mescalero
Mescalero Thread-leg Katydid
Arethaea mescalero is a species of thread-leg katydid in the family Tettigoniidae, described by Hebard in 1936. This phaneropterine katydid is endemic to sand dune habitats in the southwestern United States, particularly in New Mexico. The species is characterized by its slender, elongated legs adapted for life in sandy environments. It is one of several species in the genus Arethaea, commonly known as thread-leg katydids, which are specialized for sandy habitats.
Argyresthia calliphanes
A small moth in the family Argyresthiidae, described by Edward Meyrick in 1913. Adults are active from June to August. Larvae are leaf miners that feed on Alnus species. The species occurs across much of North America, from eastern Canada to the Pacific coast.
Argyrodes elevatus
dew-drop spider, American Dewdrop Spider
Argyrodes elevatus is a kleptoparasitic spider in the family Theridiidae that steals food from the webs of other spiders rather than building its own. Adults measure 4–7 mm in length, with males smaller than females. The species exhibits specialized adaptations for stealth, including vibrational detection of host activity, rapid prey theft completed in under 12 seconds, and nocturnal activity patterns that oppose those of diurnal host species. Courtship involves males presenting silk-wrapped prey as nuptial gifts to females.
Argyrostrotis sylvarum
Woodland Chocolate Moth, Brown Wavy Line Argyrostrotis
A small nocturnal moth in the family Erebidae, first described by Achille Guenée in 1852. It occurs in woodland habitats of the southeastern United States. The species has a wingspan of approximately 28 mm. It is known by two common names reflecting its coloration and habitat association.
Argyrotaenia amatana
pondapple leafroller moth
Argyrotaenia amatana is a small tortricid moth precinctive to Florida and The Bahamas. Adults have a wingspan of 13–16 mm and have been recorded active nearly year-round, with peak activity from October through April. The species is associated with native Florida vegetation in scrub and wetland habitats.
Argyrotaenia juglandana
Hickory Leafroller Moth
Argyrotaenia juglandana is a small tortricid moth commonly known as the hickory leafroller moth. It is native to eastern North America, where its larvae feed on the foliage of hickory, walnut, and related hardwood trees. Adults are active from spring through mid-summer and are frequently encountered in deciduous woodlands and parks.
Argyrotaenia quercifoliana
Yellow-winged Oak Leafroller Moth
Argyrotaenia quercifoliana, the yellow-winged oak leafroller moth, is a small tortricid moth found in eastern North America. Adults fly from May to July and are attracted to light. The species is associated with oak and witch-hazel, with larvae feeding on leaves of these host plants. It is one of numerous leafroller moths in the genus Argyrotaenia, many of which are economically significant orchard pests.
Argyrotaenia velutinana
Red-banded Leafroller Moth, Redbanded Leafroller
A small tortricid moth with a wingspan of 13–20 mm, found across eastern North America. The caterpillars are highly polyphagous, feeding on leaves and fruits of numerous plants including apple and other fruit trees. Adults are frequently attracted to lights and are active across much of the year. The species is occasionally a pest in orchards.