Siricidae (Horntails)

Horntail or wood wasp is the common name for any of the 150 non-social species of the family Siricidae, of the order Hymenoptera, a type of xylophagous sawfly. This family was formerly believed to be the sole living representative of the superfamily Siricoidea, a group well represented in Paleogene and Mesozoic times, but the family Anaxyelidae has been linked to this group. Siricidae has two sub families, Siricinae and Tremecinae. Siricinae infest needle-leaved trees and Tremecinae infest broad-leaved trees. There are ten living genera placed in the family, and an additional three genera described from fossils. The last tergite of the abdomen has a strong, projecting spike, thus giving the group its common name (the ovipositor is typically longer and also projects posteriorly, but it is not the source of the name). A typical adult horntail is brown, blue, or black with yellow parts, and may often reach up to 4 cm (1.6 in) long. The pigeon horntail(Tremex columba) can grow up to 5 cm (2.0 in) long (not counting the ovipositor), among the longest of all Hymenoptera.
Female horntails lay their eggs in trees. The larvae bore into the wood and live in the tree for up to two years, possibly more. They typically migrate to just under the bark before pupation.
The spiral groove on the ovipositor is visible on the photograph but not easily to the naked eye.
Check out Wikipedia for more details!
== Genus and Species ==
* Sirex
** S. noctilio (Sirex Woodwasp)