A male sirex juvencus, a type of wood wasp, was captured in a coalpit near Wigan and sent to a naturalist for identification. The insect was likely introduced as a larva in pit-props imported from abroad.
Identification and Behavior
The specimen, identified as a male sirex juvencus, belongs to the group of tailed wasps or saw-flies. Female sirex wasps lay their eggs in fir or pine trees, and the larvae cause significant damage by boring tunnels in wood, even attacking sound timber. However, some experts believe that infested trees are usually past their prime.
Comparison with Sirex Gigas
A larger and more striking species, sirex gigas, is also known. Opinions differ on which species is more common in England. One authority claims the smaller sirex juvencus is more abundant, while a recent writer suggests the opposite, though the smaller species is prevalent on the continent. Given that pit-props are often imported, the insect likely originated abroad.
Several other insects have been found in mines introduced via wood, including a longicorn beetle with notably long antennae.
