Siricides are similar to wasps . Adults have a massive, cylindrical black or metallic blue body. They are 2.5 to 4 cm long. Males are generally smaller, but more colorful than females. Sometimes they have yellow or red markings. They have four translucent wings and their flight is powerful and skillful.
In both sexes, the tip of the abdomen ends in a lance-shaped appendage, hence their English name horntails. The female also has a slender, elongated egg-laying organ, called an ovipositor, at the end of the abdomen. The whitish larvae have a soft body and can measure up to 4.5 cm.
After mating, the female searches for dying or recently cut trees. Using her egg-laying organ, the ovipositor, she deposits her eggs one by one, about 2 cm below the surface. A female produces 300 to 400 eggs which will hatch three to four weeks later. The larvae feed on the wood by digging tunnels for two years sometimes longer, then they transform into pupae.
Pupation takes place in a tunnel, just under the bark, sheltered by a cocoon made by the larva. The adult emerges in late summer.
What you need to know
Despite their sharp appendages, siricides do not sting. They don’t bite either.
This family has about 150 species.
Even though their larvae feed on wood, siricides are rarely in sufficient numbers to cause serious damage to trees. Females usually select trees in poor condition to lay their eggs. By tunneling through the wood, however, the larvae can weaken the tree and make it more vulnerable to wind breakage.