Nearctic
Guides
Xantholobus arizonensis
Xantholobus arizonensis is a treehopper species in the family Membracidae, first described by Funkhouser in 1943. The genus Xantholobus belongs to the tribe Smiliini within the subfamily Smiliinae. As with other treehoppers, this species possesses an enlarged and often elaborately modified pronotum that extends over the thorax. Very little specific information is documented about this particular species beyond its taxonomic description and geographic association with Arizona.
Xantholobus coconinus
Xantholobus coconinus is a treehopper species in the family Membracidae, described by Ball in 1932. It belongs to the tribe Smiliini within the subfamily Smiliinae, a group characterized by diverse pronotal modifications. The genus Xantholobus occurs in North America, with this species recorded from Arizona. Like other membracids, it possesses an enlarged pronotum that extends over the thorax and often exhibits plant-mimicking or other specialized morphological forms.
Xantholobus hirsutus
Xantholobus hirsutus is a treehopper species in the family Membracidae, described by Ball in 1932. Like other members of the tribe Smiliini, it possesses an enlarged and often elaborately modified pronotum that extends over the body. The genus Xantholobus is part of the diverse New World treehopper fauna, with this species known from the southwestern United States. Treehoppers in this group are characterized by their distinctive pronotal shapes and association with woody host plants.
Xantholobus nigrocinctus
A Nearctic treehopper species in the tribe Smiliini, characterized by its distinctive pronotal morphology. The species epithet "nigrocinctus" (Latin for "black-banded") refers to color pattern features. Like other members of the genus Xantholobus, it possesses the enlarged, often elaborately shaped pronotum typical of Membracidae. The species was described by Van Duzee in 1908 and is part of the diverse Smiliinae radiation in North America.
Xanthonia vagans
Large Juniper Xanthonian
Xanthonia vagans is a species of leaf beetle in the family Chrysomelidae. It is associated with juniper host plants and has a relatively large body size compared to congeners. The species occurs in arid and semi-arid regions of the southwestern United States and northwestern Mexico.
Xanthorhoe decoloraria
Red Carpet
Xanthorhoe decoloraria, commonly known as the red carpet, is a small geometrid moth described by Eugenius Johann Christoph Esper in 1806. The species exhibits considerable wing pattern variation and is distributed across northern Europe, Asia, and North America, with southern populations restricted to mountainous regions. Adults are active during mid-summer, and larvae feed on Alchemilla species.
Xenochodaeus luscinus
Xenochodaeus luscinus is a species of sand-loving scarab beetle in the family Ochodaeidae. It was described by Howden in 1968. The species is known from western Canada, specifically Alberta and British Columbia. Like other members of its family, it is associated with sandy habitats.
Xenochodaeus musculus
sand-loving scarab beetle
Xenochodaeus musculus is a species of sand-loving scarab beetle in the family Ochodaeidae, first described by Thomas Say in 1835. The species is distributed across the Nearctic region of North America, with records from numerous U.S. states and the Canadian province of Ontario. Like other members of its family, it is associated with sandy habitats. The specific epithet 'musculus' refers to its small, mouse-like size.
Xenorhipidini
Xenorhipidini is a small tribe of jewel beetles (family Buprestidae) comprising approximately 8 described species across three genera. The tribe is notable for extreme sexual dimorphism in antennal structure: males possess highly modified flabellate or lamellate antennae with expanded distal segments covered in olfactory sensillae, while females retain unmodified serrate antennae. This modification, unique among non-monotypic buprestid tribes, is associated with pheromone detection. Members are found in arid and semi-arid regions of North and South America and the West Indies.
Xeris spectrum
wood wasp, horntail
Xeris spectrum is a large horntail or wood wasp in the family Siricidae, notable within its family for lacking the fungal symbionts that other siricid wasps use to aid larval development in wood. Females possess a powerful ovipositor used to drill into coniferous trees and deposit eggs beneath the bark. The species is widespread across Europe, Asia, Africa, and North America, where it develops in the wood of fir, spruce, pine, and larch. Development from egg to adult takes several years, with larvae emerging in two distinct cohorts—some in summer alongside other wood wasps, others the following spring. The species is considered a timber pest due to larval tunneling that degrades wood quality.
Xeropsamobeus
Xeropsamobeus is a genus of aphodiine dung beetles in the family Scarabaeidae, containing approximately 10 described species. The genus was established by Saylor in 1937. Species in this genus are native to arid regions of western North America, with several species described from desert habitats in the southwestern United States and Mexico. Most species were described or revised by Gordon and Skelley in 2007.
Xeropsamobeus asellus
Xeropsamobeus asellus is a small aphodiine dung beetle in the family Scarabaeidae. The species was described in 1907 and has been recorded from the United States and Mexico, with some sources suggesting it may be endemic to Texas. As a member of the subfamily Aphodiinae, it belongs to a group commonly known as lesser dung beetles. Very few observations of this species have been documented.
Xyela bakeri
Xyela bakeri is a Nearctic sawfly species in the family Xyelidae, first described by Konow in 1898. It belongs to the X. bakeri species group, which includes the Japanese X. fusca and an undescribed Chinese species—one of only two Xyela groups with trans-Beringian distributions. The species is endemic to North America with records spanning from Quebec to Florida and west to British Columbia, California, and the Yukon Territory. Larvae develop as internal feeders in pine cones, with documented hosts including multiple Pinus species in subgenus Pinus.
Xylobiops basilaris
Red-shouldered Bostrichid
Xylobiops basilaris, commonly known as the red-shouldered bostrichid, is a species of horned powder-post beetle in the family Bostrichidae. The species was first described by Thomas Say in 1824. It belongs to a family of beetles known for their wood-boring larvae, which can cause significant damage to timber and wooden structures. The common name refers to distinctive reddish coloration on the shoulder region of the adult beetle.
Xylophanes pluto
Pluto sphinx
Xylophanes pluto, commonly known as the Pluto sphinx, is a hawkmoth in the family Sphingidae. It is distinguished from congeners by a prominent broad chrome-yellow band across the wings. The species occurs from Argentina northward through Central America to the southern United States, with multiple generations per year in Florida and Texas and year-round activity in tropical regions. Larvae feed on specific host plants including Chiococca, Erythroxylum, Hamelia patens, and Morinda royoc.
Xyloryctes
rhinoceros beetles
Xyloryctes is a genus of rhinoceros beetles in the family Scarabaeidae, tribe Oryctini, subfamily Dynastinae. The genus contains approximately 13 described species distributed primarily in the Nearctic and Neotropical regions. Adults are characterized by prominent cephalic horns, particularly in males, and are nocturnally active, frequently attracted to artificial lights. The genus has been documented as a vector for the giant thorn-headed worm of swine (Macracanthorhynchus hirudinaceus), with X. satyrus representing a newly recorded host for this acanthocephalan parasite.
Xylota segnis
Orange-belted Leafwalker, brown-toed forest fly, lazy wood fly
Xylota segnis is a common Palearctic and Nearctic hoverfly distinguished by its black abdomen with a prominent orange or yellowish-red patch on tergites 2 and 3. Adults are notable for their sedentary behavior, often resting motionless on leaves rather than actively flying. The species is polyvoltine with up to three generations annually and has been observed from April through September. Larvae develop in decaying tree sap and have also been recorded from decaying human remains.
Xylotrechus obliteratus
Xylotrechus obliteratus is a longhorned beetle in the family Cerambycidae, described by John Lawrence LeConte in 1873. It belongs to the tribe Clytini, a group of wood-boring beetles often characterized by patterned or banded elytra. The species name 'obliteratus' (meaning 'obliterated' or 'erased') likely refers to reduced or indistinct markings compared to congeners. Like other members of the genus Xylotrechus, this species is associated with woody plants, though specific host records are limited in the available literature.
Yelicones nigromarginatus
Yelicones nigromarginatus is a species of braconid wasp in the subfamily Rogadinae, described from specimens collected in Vermont, USA. The species name refers to the dark marginal coloration of the wings. Like other members of Yelicones, it is presumed to be a koinobiont endoparasitoid of lepidopteran larvae, though specific host records for this species remain undocumented. It is one of approximately 50 described species in the genus Yelicones, which occurs primarily in the Neotropical and Nearctic regions.
Yugus
Yugus is a genus of stoneflies in the family Perlodidae, established by Ricker in 1952. Members of this genus are part of the diverse Nearctic stonefly fauna, with documented occurrence in the eastern United States. As with other perlodid stoneflies, they are aquatic insects with nymphal stages in streams and rivers. The genus is classified within the tribe Perlodini, reflecting close relationships with other genera in this group.
Zaeucoila robusta
Zaeucoila robusta is a species of parasitoid wasp in the family Figitidae, subfamily Eucoilinae. First described by Ashmead in 1894 as Chrestosema robusta, this species is now placed in the genus Zaeucoila. Members of this genus are known as figitid wasps that parasitize dipteran larvae, particularly those associated with decaying organic matter. The species has been recorded from Brazil and Canada.
Zagrammosoma trifurcatum
Zagrammosoma trifurcatum is a parasitoid wasp species in the family Eulophidae, described in 2021 from specimens collected in Belize and California, USA. The species belongs to a genus commonly known as "tattooed wasps" due to distinctive yellow and black markings on the thorax. As part of a comprehensive molecular and morphological revision, this species was distinguished from congeners using genetic markers (28S, ITS2, COI) and morphological characters. The specific epithet "trifurcatum" refers to a three-pronged or forked structure, likely a diagnostic morphological feature.
Zaischnopsis bouceki
Zaischnopsis bouceki is a species of parasitic wasp in the family Eupelmidae, described by Gibson in 2005. The genus Zaischnopsis was established to accommodate species previously placed in related eupelmid genera, distinguished by specific morphological features of the mesosoma and wing venation. This species is part of the diverse Chalcidoidea superfamily, which contains numerous parasitoids of other insects. The species epithet honors the Czech entomologist Zdeněk Bouček, who made substantial contributions to chalcidoid systematics.
Zelotes puritanus
Zelotes puritanus is a species of ground spider in the family Gnaphosidae. It has a broad geographic distribution spanning North America, Europe, Turkey, and a continuous range from Russia to Kazakhstan. As a member of the genus Zelotes, it belongs to a diverse group of active hunting spiders commonly known as ground spiders.
Zeluroides
Zeluroides is a genus of assassin bugs in the family Reduviidae, established by Lent & Wygodzinsky in 1948. The genus contains at least two described species: Z. americanus and Z. mexicanus. As members of the Reduviinae subfamily, these predatory true bugs possess the raptorial forelegs and piercing-sucking mouthparts characteristic of assassin bugs.
Zenodoxus heucherae
Zenodoxus heucherae is a species of clearwing moth in the family Sesiidae, first described by Henry Edwards in 1881. The species epithet references Heuchera, a genus of flowering plants in the saxifrage family, suggesting a possible host plant association. As a member of the subfamily Tinthiinae, it belongs to a group of sesiid moths often associated with herbaceous or shrubby hosts. The species is known from the Nearctic region, though detailed biological information remains limited.
Zenodoxus mexicanus
Zenodoxus mexicanus is a clearwing moth (family Sesiidae) described by Beutenmüller in 1897. The genus Zenodoxus belongs to the subfamily Tinthiinae, a group of sesiid moths characterized by their wasp-mimicking appearance and diurnal activity patterns. This species occurs in the Nearctic and Neotropical regions, with the specific epithet suggesting a Mexican distribution. Clearwing moths in this family are typically associated with woody plants, with larvae often boring into stems or roots.
Zenodoxus palmii
Zenodoxus palmii is a species of clearwing moth in the family Sesiidae, first described by Berthold Neumoegen in 1891 from specimens collected in the southwestern United States and Mexico. As a member of the subfamily Tinthiinae, it belongs to a group of sesiid moths often associated with monocot host plants. The species exhibits the characteristic wasp-mimicry typical of clearwing moths, with reduced wing scaling that leaves transparent areas on the wings. It is one of relatively few described species in the genus Zenodoxus, which is primarily distributed in the Nearctic and Neotropical regions.
Zenodoxus sidalceae
Zenodoxus sidalceae is a clearwing moth in the family Sesiidae, described by Engelhardt in 1946. The species epithet 'sidalceae' suggests a likely association with plants in the genus Sidalcea (mallow family, Malvaceae), though this relationship requires confirmation. As a member of the Tinthiinae subfamily, it belongs to a group of sesiid moths often characterized by wasp-mimicking appearance and diurnal activity. The species is poorly known, with limited observational records.
Zethus montezuma
Zethus montezuma is a species of potter wasp in the family Vespidae, subfamily Eumeninae. It was described by Henri de Saussure in 1857. The genus Zethus comprises primarily neotropical potter wasps, with this species representing part of the group's diversity in the southern Nearctic and northern Neotropical regions. As with other eumenine wasps, it is a solitary wasp that constructs mud nests provisioned with paralyzed prey for its larvae.
Zilus horni
Eastern Velvethead Ladybug
Zilus horni is a minute lady beetle in the family Coccinellidae, measuring approximately 1.40–1.60 mm in length. The species is native to eastern North America, with records from Maryland to Florida and west to Wisconsin and Louisiana. It was described by Gordon in 1985 and named in honor of American entomologist George H. Horn. The specific epithet commemorates Horn's contributions to coleopterology.
Zimmermannia mesoloba
Zimmermannia mesoloba is a species of minute moth in the family Nepticulidae, originally described by Davis in 1978 as Ectoedemia mesoloba and later transferred to Zimmermannia. Nepticulidae are among the smallest Lepidoptera, commonly known as pygmy moths or midget moths. Species in this genus are leaf miners, with larvae feeding inside leaf tissue.
Zimmermannia phleophaga
Phelophagan Chestnut Moth
Zimmermannia phleophaga is a species of moth in the family Nepticulidae, commonly known as the Phelophagan Chestnut Moth. It belongs to a genus of minute moths whose larvae are leaf miners. The species name "phleophaga" suggests an association with feeding on plant tissues, though specific host plant relationships require verification. The species was originally described by Busck in 1914 and later transferred to the genus Zimmermannia.
Zomaria interruptolineana
Broken-lined Zomaria Moth, broken-lined zomarium
Zomaria interruptolineana, commonly known as the Broken-lined Zomaria Moth, is a species of tortricid moth in the family Tortricidae. It was described by Fernald in 1882 and is found in the Nearctic region. The species has been assigned MONA/Hodges number 2750.
Zuphioides longicolle
Zuphioides longicolle is a ground beetle species in the family Carabidae, described by LeConte in 1879. It belongs to the tribe Zuphiini, a group of carabid beetles often associated with specific microhabitats. The species occurs in both the United States and Mexico, with limited observational records available.
Zyginama erosa
Zyginama erosa is a species of leafhopper in the family Cicadellidae, first described by McAtee in 1924. It belongs to the subfamily Typhlocybinae and tribe Erythroneurini, a group of small, often colorful leafhoppers known for their distinctive wing venation patterns. The genus Zyginama is part of a diverse assemblage of Nearctic leafhoppers, with this species recorded from California.
Zygota
Zygota is a genus of small parasitoid wasps in the family Diapriidae. Members are medium-sized (2.5–4.0 mm), melanic, and pubescent with brightly colored appendages. The genus occurs in the Palearctic and Nearctic regions, with 19 species documented in Germany alone. Taxonomic boundaries between Zygota and the related genus Pantoclis have been clarified through recent morphological and DNA barcoding studies.