The adult wasp has a straight-sided cylindrical reddish-brown body with a yellow-banded and black pattern on the abdomen and is 1 to 1-1/2 inches long.
The wings are dark brown to black. Both sexes have projections called “horntails on the end of the abdomen.” Females also have a longer protrusion called an ovipositor that emerges from the underside of the abdomen and is used to deposit eggs in tree trunks.
Wood wasps are also known as Siricidae. Adults can be mistaken for sawflies.
Host plants:
Elms and sugar maples are favored hosts, although other hardwoods can be affected, including silver maple, ash, cottonwood, and elm.
Territory: Pigeon Tremex is native to eastern and western North America
Damage caused by Pigeon Tremex:
The larvae form meandering tunnels within the sapwood of dead and dying trees. Wind breakage may occur in densely tunneled trees. On the other hand, the damage is generally limited to deadwood or stressed portions of the tree. Pigeon tremex and similar horntails aren’t “aggressive” wood borers; thus, they can’t grow in healthy trees. This insect, a thick-waisted cylindrical wasp approximately one and a half inches long, gets a lot of attention because of its size. In addition, the females have a large “stinger” (ovipositor), which is harmless. Pigeon tremex (and other horntails) are the only common insects that emerge from the tree with a circular exit hole.
Life history and Habits:
The pigeon tremex is active from June through early October as an adult. Females can be seen creeping along with the bark and inserting their ovipositor into the trunk on rare occasions. A few eggs (2 to 7) will be deposited into the wood if the circumstances under the bark are acceptable, particularly if the moisture level is low enough. The white-rot fungus Daedalea unicolor is also introduced along with the eggs. This fungus grows in the wood before the horntail larvae do, which is necessary for their growth. Infection of trees with the white-rot fungus speeds up decomposition and damages the structure of the trees. Larvae require nearly a year to fully mature before pupating just beneath the bark. After roughly a month of pupation, the adult emerges and cuts a circular exit hole by which it exits the tree.
