The Sirex woodwasp
, Sirex noctilio
, is a species of horntail
, native to Europe
and northern Africa
. Adults vary in length from 9 to 36 millimetres (0.4 to 1.4 in). It 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
. It can attack a wide variety of pine species, although some species seem to be more susceptible than others, and it is often stressed trees that 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 ascospores from the symbiotic fungus Amylostereum areolatum are also pathogenic.