Horntail
Guides
Sirex areolatus
Areolate Woodwasp
Sirex areolatus, commonly known as the Areolate Woodwasp, is a species of horntail wasp in the family Siricidae. Like other members of its family, females possess a prominent ovipositor used to deposit eggs into wood, and a shorter dorsal cornus that gives the group its common name. The species has been recorded in parts of Canada including British Columbia and Nova Scotia, with some doubtful records from Europe. As a wood-boring insect, it develops in dead or dying hardwood trees, where larvae feed on wood-rotting fungi introduced by the female during oviposition.
Sirex cyaneus
blue horntail
Sirex cyaneus, commonly known as the blue horntail, is a species of woodwasp in the family Siricidae. Native to forests in Alberta, Canada, adults reach approximately 2 cm in length. The species serves as a host for parasitoid wasps including Rhyssa persuasoria and Ibalia leucospoides, which have been studied for potential biological control applications.
Tremecinae
woodwasps, horntails
Tremecinae is a subfamily of woodwasps (Siricidae) distinguished from Siricinae by its association with the white-rot fungus Cerrena unicolor rather than Amylostereum. Unlike Siricinae, which carry symbiotic fungi in specialized mycangia, at least some Tremecinae species lack these structures and do not internally transport fungal symbionts. Females locate host wood already infected with sapwood-decaying fungi using volatile compounds. The subfamily includes forest pests that interact with fungal communities in decaying wood.
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.
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.
Urocerus flavicornis
Yellow-horned Horntail, Yellow-horned Horntail Wasp
Urocerus flavicornis is a large wood-boring wasp in the family Siricidae, commonly known as the yellow-horned horntail. Native to North America, this species develops inside dead or dying hardwood trees. Adults are active primarily in late summer and fall. The species is non-venomous and poses no threat to humans despite its intimidating appearance.
Urocerus taxodii
Taxodium horntail
Urocerus taxodii is a species of woodwasp in the family Siricidae, described by Ashmead in 1904. As a member of the genus Urocerus, it shares the characteristic elongated, cylindrical body form and prominent cornus (horn-like projection at the abdomen tip) typical of horntails. The species is associated with Taxodium (cypress/bald cypress) as a larval host, as indicated by its specific epithet. Like other siricids, females possess a long ovipositor for drilling into wood to deposit eggs, and they vector wood-decaying fungi that serve as food for their larvae.
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.