Sirex noctilio

Sirex noctilio, known as the Midnight woodwasp, European woodwasp, European horntail woodwasp, or sirex woodwasp, is a species of woodwasp, native to Europe, Asia, and northern Africa. Adults vary in length from 9 to 36 mm (3⁄8 to 1+3⁄8 in).

This woodwasp is an invasive species in many parts of the world, including Australia, New Zealand, North America, South America, and South Africa, where it has become a significant economic pest of pine trees. The wasp can attack a wide variety of pine species, although some species seem to be more susceptible than others, and stressed trees often are attacked.

During oviposition, the female wasp lays two eggs with or without a mucoid substance and a symbiotic fungus for the larvae to feed on once they hatch. The mucoid substance is toxic to trees and aids in tree decline. The arthrospores from the symbiotic fungus, Amylostereum areolatum, are also pathogenic.