Forest-insect
Guides
Stigmella
pygmy leaf-mining moths
Stigmella is a large genus of minute moths in the family Nepticulidae, commonly known as pygmy leaf-mining moths. Adults typically measure 2–6 mm in wingspan, making them among the smallest Lepidoptera. The genus is characterized by larvae that feed internally in leaf mines of diverse host plants. Many species exhibit narrow host specificity, with individual species restricted to particular plant genera or families. Stigmella contains hundreds of described species distributed across temperate and tropical regions worldwide.
Stigmella caryaefoliella
hickory leafminer
Stigmella caryaefoliella is a pygmy leaf-mining moth in the family Nepticulidae, native to North America. The species is a specialist herbivore whose larvae feed on hickory (Carya) leaves, creating distinctive serpentine mines. Adults are minute, typically measuring only 2–5 mm in wingspan, with reduced mouthparts. The species was originally described as Nepticula caryaefoliella by Clemens in 1861 and later transferred to Stigmella.
Sylvicola notialis
Sylvicola notialis is a species of wood gnat in the family Anisopodidae, described by Stone in 1965. Wood gnats in this genus are associated with decaying wood and moist forest habitats. The species is part of a group of Diptera commonly found in woodland environments where larvae develop in rotting wood or other decomposing plant material.
Symydobius americanus
Dark birch aphid
Symydobius americanus is a small aphid species in the family Aphididae, commonly known as the dark birch aphid. It is specifically associated with birch trees (Betula species), particularly paper birch (Betula papyrifera). The species has been studied in the context of plant-mediated interactions between leaf-chewing herbivores and phloem-feeding insects, with research showing that prior caterpillar damage to host leaves does not significantly affect aphid colony performance.
Synecdoche dimidiata
Synecdoche dimidiata is a planthopper in the family Achilidae, a group of fulgoroid insects associated with fungal associations. This species belongs to a poorly studied group of true bugs that feed on fungal hyphae rather than plant sap. Records indicate presence in eastern North America from New England to the southeastern United States.
Temnoscheila
bark-gnawing beetles
Temnoscheila is a genus of predatory bark-gnawing beetles in the family Trogossitidae, containing approximately 19 described species. Members of this genus are agile beetles often found in association with bark and wood of trees. At least one species, T. virescens, has been demonstrated to use cerambycid beetle pheromones to locate its prey, indicating sophisticated chemical eavesdropping behavior. The genus was historically often misspelled as "Temnochila" in literature.
Tethida barda
Black-headed Ash Sawfly
Tethida barda is a sawfly species in the family Tenthredinidae, commonly known as the Black-headed Ash Sawfly. The species is associated with ash trees (Fraxinus species) as a host plant. It is found across eastern and central Canada and the northeastern United States. The larvae feed on ash foliage and can occasionally cause noticeable defoliation.
Thanasimus undatulus
Wavy Checkered Beetle
Thanasimus undatulus is a species of checkered beetle (family Cleridae) known as the Wavy Checkered Beetle. It is a documented predator of bark beetles, specifically the spruce beetle (Dendroctonus rufipennis). The species responds to synthetic pheromones used by its prey, particularly frontalin. It occurs in North America and Central America.
Tipula morrisoni
Tipula morrisoni is a species of large crane fly in the family Tipulidae, first described by Charles Paul Alexander in 1915. It belongs to the diverse genus Tipula, which contains hundreds of species distributed across the Northern Hemisphere. As a crane fly, it exhibits the characteristic elongated body, extremely long legs, and single pair of wings typical of the family. The species is known from the eastern and central United States.
Tramini
Tramini is a tribe of aphids within the family Aphididae, subfamily Lachninae. Members are medium to large aphids characterized by robust bodies, long antennae, and siphunculi that are either absent or reduced to small pores. The tribe includes conifer-feeding aphids, with many species associated with pine (Pinus) hosts.
Tremex
woodwasp, horntail
Tremex is a genus of woodwasps (family Siricidae) containing approximately 33 species with a primarily Holarctic distribution. These large, cylindrical wasps are characterized by females possessing a prominent, spear-like ovipositor used to bore into hardwood trees and lay eggs. Unlike their relatives in the subfamily Siricinae, Tremex species associate with the white-rot fungus Cerrena unicolor rather than Amylostereum. The larvae tunnel through wood and feed on both the fungus and decayed wood material. Though they appear intimidating due to their size and visible ovipositor, they are non-venomous and pose no threat to humans.
Tremex columba
pigeon tremex, pigeon horntail
Tremex columba is a large horntail wasp native to North America. Females possess a prominent ovipositor used to drill into dead or dying hardwood trees to deposit eggs. The species has an obligate symbiotic relationship with the wood-rotting fungus Daedalea unicolor, which females introduce during oviposition and which larvae require for development. Larval development takes one to two years, during which they tunnel through fungus-infected wood. The species is not harmful to humans and does not sting.
Trigonorhinus limbatus limbatus
Trigonorhinus limbatus limbatus is a subspecies of fungus weevil in the family Anthribidae. It is characterized by distinct dark markings on the elytra and a somewhat elongated body form typical of the genus. The subspecies is part of a complex that requires careful examination for proper identification. It has been documented in specific regions of North America.
Trioza magnoliae
Red Bay Psyllid
Trioza magnoliae, commonly known as the Red Bay Psyllid, is a gall-forming psyllid native to eastern North America. This species induces characteristic galls on the leaves of native Persea bay trees, particularly red bay (Persea borbonia) and related species. The insect has a wide distribution across the eastern and central United States. While primarily an ecological curiosity due to its gall-forming habit, it has gained attention in relation to the decline of red bay populations caused by the invasive laurel wilt disease, as the psyllid's host trees face significant mortality.
Triplax
pleasing fungus beetles
Triplax is a genus of pleasing fungus beetles in the family Erotylidae, containing approximately 50 described species distributed across North America, Europe, and East Asia. Members are small beetles (typically 3–6 mm) strongly associated with fungi, particularly mushrooms. Some species are significant pests of cultivated oyster mushrooms. The genus is taxonomically placed in tribe Tritomini within subfamily Erotylinae.
Tuberculatus pallidus
pale oak aphid
Tuberculatus pallidus is a species of aphid in the family Aphididae, described by Davidson in 1919. It belongs to the genus Tuberculatus, which comprises aphids primarily associated with oak trees (Quercus spp.). The species name "pallidus" refers to its pale coloration. Like other members of its genus, it is likely a specialist feeder on oak foliage, though specific biological details remain poorly documented in accessible literature.
Urocerus
horntail, woodwasp
Urocerus is a genus of horntails (woodwasps) in the family Siricidae containing approximately seven to eight described species. These large, non-venomous wasps are characterized by their elongated, cylindrical bodies and prominent cornus (horn-like spine) at the tip of the abdomen. Females possess a long, drill-like ovipositor used to insert eggs into dead, dying, or weakened trees. Species in this genus are obligate mutualists with wood-decaying fungi, which they vector and cultivate for larval nutrition. Several species have broad distributions across the Northern Hemisphere, with some introduced outside their native ranges.
Urocerus cressoni
Black-and-red Horntail
Urocerus cressoni is a large wood-boring wasp in the family Siricidae, commonly known as the Black-and-red Horntail. Females range from 37–50 mm in length, males 18–37 mm. The species is native to North America and has been recorded across Canada from Nova Scotia to Manitoba. Like other horntails, females possess a prominent ovipositor for drilling into wood to deposit eggs, along with a shorter dorsal spine (cornus) that gives the family its common name. The species is non-venomous and poses no threat to humans.
Xiphydria abdominalis
Xiphydria abdominalis is a species of wood-wasp in the family Xiphydriidae, a group of sawflies that develop in decaying wood. The genus Xiphydria contains approximately 15 species in North America. These insects are associated with dead and dying hardwood trees, where larvae tunnel in the wood. Adults are diurnal and have been observed flying near host material. The species is part of a guild of wood-inhabiting insects that play important roles in forest decomposition processes.
Xiphydria canadensis
Canadian Wood Wasp
Xiphydria canadensis is a species of wood wasp in the family Xiphydriidae, native to North America. Wood wasps in this family are characterized by their elongated bodies and long ovipositors used to drill into wood to deposit eggs. The species is known to be a host for parasitic ichneumonid wasps, specifically Rhyssella nitida, which uses its long ovipositor to reach the wood wasp larvae inside logs and dead trees. Adults are active during spring and early summer.
Xiphydria tibialis
Xiphydria tibialis is a species of wood wasp in the family Xiphydriidae, first described by Thomas Say in 1824. It is one of several species in the genus Xiphydria, which are known as wood wasps due to their larvae developing in dead or dying wood. The species is native to North America. Limited observational data exists for this species, with only 8 documented observations on iNaturalist as of the source date.
Xorides
Xorides is a genus of ichneumon wasps (family Ichneumonidae, subfamily Xoridinae) comprising at least 150 described species. Members are ectoparasitoids of wood-boring beetle larvae, particularly in the families Cerambycidae and Buprestidae. Females possess elongated ovipositors adapted for drilling through wood to reach concealed hosts. The genus has a global distribution spanning the Palaearctic, Afrotropical, and Nearctic regions, with substantial diversity in China and Europe.
Xyleborus celsus
Hickory Timber Beetle
Xyleborus celsus, commonly known as the hickory timber beetle, is a bivoltine ambrosia beetle native to North America. It specializes in colonizing stressed or dying black hickory trees (Carya texana) and other hickory species. The species overwinters as adults and completes development from egg to adult in approximately 35 days. Unlike some invasive congenerics, it appears to be a native primary colonizer of weakened trees rather than an aggressive killer of healthy hosts.
Xylomya americana
Xylomya americana is a species of fly in the family Xylomyidae, commonly known as wood soldier flies. The species was described by Wiedemann in 1821 and is found across much of North America. Wood soldier flies in this genus are typically associated with decaying wood and forest habitats. Adults are generally medium-sized flies with distinctive wing venation patterns characteristic of the family.
Xylomya terminalis
Xylomya terminalis is a species of wood soldier fly in the family Xylomyidae, described by Vasey in 1977. The species is known from the eastern United States, with records from Vermont and other states. Xylomyidae are predatory flies whose larvae develop in decaying wood and under bark. Adults are typically found in woodland habitats.
Zelus luridus
Pale green assassin bug
Zelus luridus, commonly called the pale green assassin bug, is a species of assassin bug in the family Reduviidae. It is the most common Zelus species in the eastern United States, ranging from 12.5 to 18 mm in length with a pale green base color and variable markings. The species employs a unique predation strategy using sticky secretions from leg glands to trap prey, earning it the common name 'sundew assassin bug.'