Wood wasps
Wood wasps (Siricidae) are a family of hymenopteran insects known as serious pests in forestry and the timber industry. Despite their resemblance to large wasps, they possess no stingers and are harmless to humans. Their primary biological function is to utilize wood as a substrate for their offspring's development.
What the section contains
Banded horntail
Urocerus sah
Behrens wood wasp
Sirex behrensi
Black horntail
Xeris spectrum
Black horntail
Xeris tarsalis
Blue horntail
Sirex cyaneus
California horntail
Sirex californicus
California horntail
Urocerus californicus
Ermak Woodwasp
Sirex ermak
Ghost horntail
Urocerus fantoma
Giant woodwasp
Tremex magnus
Giant woodwasp
Urocerus gigas
Japanese horntail
Urocerus japonicus
Morrison's woodwasp
Xeris morrisoni
Pigeon tremex
Tremex columba
Sirex imperialis
Sirex imperialis
Sirex nitobei
Sirex nitobei
Sirex woodwasp
Sirex noctilio
Steel-blue woodwasp
Sirex juvencus
Tremex fuscicornis
Tremex fuscicornis
White-horned wood wasp
Urocerus albicornis
Wood wasp
Sirex areolatus
Wood wasp
Tremex
Woodwasp
Sirex
Woodwasp
Urocerus augur
Woodwasp
Urocerus
Woodwasp
Xeris
Yellow woodwasp
Urocerus xanthus
Yellow-horned wood wasp
Urocerus flavicornis
Wood wasps
They typically attack coniferous tree species, including spruce, fir, pine, and larch. The insects are particularly attracted to stressed, dying, or recently felled timber. The larvae are wood-boring insects (xylophagous) that drill deep galleries into the heartwood, which compromises the structural integrity of the timber.
The life cycle of a wood wasp generally spans from 2 to 3 years. Female wasps use their specialized ovipositors to insert eggs into the tree trunk, often inoculating the wood with symbiotic fungi. These fungi break down the wood fibers, aiding the larvae in digestion. The larvae then undergo multiple stages of growth within the wood before pupating.
Economic losses associated with wood wasps are significant, as their tunnels degrade the quality of wood for construction and manufacturing. Beyond technical damage, their presence can indicate broader forest health issues. In severe infestations, the timber may be rendered completely valueless, necessitating strict management protocols.
Management and control strategies focus on sanitation and prevention:
- prompt harvesting and removal of infested or dead trees;
- proper storage of logs to minimize exposure to females;
- maintaining high tree vigor through proper forest management;
- utilizing biological control agents like parasitic wasps (e.g., Ibalia leucospoides) to regulate populations.