Other Common Names
Wood Wasps (more prominent outside of the US)
Explanation of Names
The common name of horntails refers to their abdominal spine
2 subfamilies, with 28 spp. in 5 genera in our area and ~120 spp. in 10 genera worldwide(1)
Size varies tremendously: adults of the same species may vary from 1 to 5 cm
Both sexes have a short abdominal dorsal projection (horn) that gives them their common name. Females also have an ovipositor in a sheath, placed ventrally in the abdomen.
Color is useful in identification.
Keys to genera and spp. in(1)
forests of the Northern Hemisphere south to Cuba, n. Central America, India, New Guinea, and n. Africa (2 spp. are known from tropical Africa)(3)
Wood (Tremicinae mostly on hardwoods; Siricinae, on conifers); larvae require a symbiotic fungus to digest wood(3)
. It is a complex interaction between three organisms: the wood wasp, a symbiotic wood-decaying fungus, and the host tree.
larval development may take 1 to 3 years to complete depending on species and climate(3)
Males emerge first and disperse, preventing inbreeding.
Some are serious pests of trees and spread as larvae with lumber trade.
The most important predators and parasitoids are the ichneumonid wasp Megarhyssa
and some nematodes
Horntails do not sting: what looks like a sting is the ovipositor the female uses to lay eggs in wood
Females more abundant than males
Adults fly mostly in bright sunshine