European Wood Wasp (Sirex Woodwasp)
Wood wasps, or horntails, as a group are large, robust and wasplike but do not have a constricted "waist" behind their wings like other wasps; also, they have a spear-shaped spine at their "tail end," which gave them the “horntail” name. Adult European wood wasps are metallic bluish-black with reddish-yellow legs, black feet and black antennae. Males have an orange band around the abdomen and black hind legs. Females, in addition to the “horntail,” also have a stout, long ovipositor for inserting eggs into wood.
Larvae are creamy white, legless, with a dark spine at the hind end, and thus look very much like the larvae of our native horntail species. When new adults emerge from tree trunks, they create round exit holes about 1/8 to 3/8 inch in diameter.