Woodwasp
Guides
Eriotremex
Eriotremex is a genus of woodwasps in the family Siricidae (Hymenoptera). Members of this genus are associated with coniferous hosts and are distributed in Asia and North America. At least one species, Eriotremex formosanus, has been introduced to the southeastern United States, where it has been documented in South Carolina. The genus is characterized by morphological features typical of Siricidae, including a cylindrical body and an elongated ovipositor in females.
Orus armiger
Orus armiger is a species of parasitic woodwasp in the family Orussidae, a group notable for their unique evolutionary position and specialized host-finding behavior. The family Orussidae contains only about 75 species worldwide, making it one of the smallest and least understood families of Hymenoptera. Orussid wasps are the only parasitoid wasps that attack wood-boring beetle larvae, using vibrational sounding to locate hosts within solid wood. Adults are rarely encountered in the field and are frequently mistaken for ants due to their appearance and behavior.
Orussus minutus
Orussus minutus is a rarely collected parasitic woodwasp in the family Orussidae, native to the eastern United States. The species is notable for its significant western range expansion documented through citizen science platforms and museum collections. Previously known from only about 50 specimens mainly in the Northeast, new records from Arkansas, Iowa, Minnesota, and Manitoba extend its range hundreds of miles westward. The species is extremely uncommon in collections despite intensive trapping efforts.
Orussus terminalis
Orussus terminalis is a parasitic woodwasp in the family Orussidae, a group unique among woodwasps for their parasitoid lifestyle. Like other orussids, they are rarely encountered in collections and poorly studied. The species belongs to a family whose members attack immature stages of wood-boring beetles and other woodwasps. Orussus terminalis has been recorded from eastern North America, with distribution records from Canada (Ontario, Quebec) and the United States (Vermont).
Orussus thoracicus
Orussus thoracicus is a parasitic woodwasp in the family Orussidae, one of the rarest and most unusual groups of Hymenoptera. Adults are often mistaken for carpenter ants due to their dark coloration and wing-folding behavior. The species has been recorded from Canada, specifically British Columbia, though its biology and ecology remain poorly documented. Like other orussids, it likely parasitizes wood-boring beetle larvae using specialized vibrational sounding to locate hosts.
Pseudorhyssa
Pseudorhyssa is a genus of ichneumonid wasps containing cleptoparasitic species that exploit the drill shafts of primary parasitoids to access hosts. The best-studied species, Pseudorhyssa sternata, parasitizes Siricid woodwasps by locating and utilizing oviposition holes made by the primary parasitoid Rhyssa persuasoria. Females detect host-infested trees through stimuli in larval frass, likely associated with symbiotic fungus, and locate specific drill shafts using secretions from the vaginal gland of the primary parasitoid.
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.
Sirex nigricornis
black-horned woodwasp, native woodwasp
Sirex nigricornis is a native North American woodwasp (family Siricidae) that inhabits pine forests in the eastern United States. Unlike the invasive congener Sirex noctilio, this species primarily attacks stressed, dying, or recently dead pines rather than healthy trees. Females possess a prominent ovipositor for drilling into wood and deposit eggs along with a symbiotic wood-decaying fungus. The species serves as host for multiple parasitoids including the nematode Deladenus proximus, which sterilizes female eggs, and the ichneumonid wasp Rhyssa howdenorum.
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.
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 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.