Siricidae

Taxonomy

Superfamily: Siricoidea

Family: Siricidae
Family common name: horntails and wood wasps
Subfamilies: Auliscinae, Gigasiricinae, Siricinae, Tremicinae

Background

The family Siricidae is represented in North America by two subfamilies (Goulet 1992). All horntail species are wood-borers as larvae that feed on symbiotic wood-decaying fungus. Some species are economic pests of trees grown for lumber. This family is fairly easy to recognize by the large pointed cornus and the large collar-like pronotum (Goulet 1992). Many species are large and have either metallic coloring, bright yellow patterning, or exceedingly long and obvious ovipositor sheaths that look like a wasp’s stinger (Schiff et al. 2012).

Diversity

Siricidae includes 20 genera and 124 species worldwide. Five genera and 27 species are Nearctic in distribution (Taeger et al. 2018).

North American genera

Eriotremex
Sirex
Tremex
Urocerus
Xeris

Diagnostic characteristics

Host associations

The subfamily Siricinae feeds on conifer trees from the families Pinaceae and Cupresaceae. Tremicinae species feeds on angiosperm trees including species from the families Aceraceae, Fabaceae, Fagaceae, Rosaceae, Salicaceae, Ulmaceae, and Betulaceae (Smith and Middlekauff 1987, Schiff et al 2012).

May be confused with

Siricidae can be distinguished from other Siricoidea families by the distinctly collar-like pronotum and the pointed cornus (Goulet 1992).

Life history

Siricidae in North America are wood borers. Usually they oviposit into decayed or damaged wood while also depositing a symbiotic wood-decaying fungus. The developing larvae feed on the fungus (Schiff et al. 2012).

Sirex noctilio is an example of a horntail pest with extensive economic impact.

Distribution

World: The range of the family includes Europe, Asia, and North America. Sirex noctilio has been introduced and is established in South America, South Africa, and Australia (Schiff et al. 2012).

North America: The Siricidae occurs throughout forested regions of Canada and the United States as far north as Alaska, south into Mexico and the Caribbean (Schiff et al. 2012).

Sirex cyaneus female lateral habitus; photo by H. Goulet, CNC

Sirex cyaneus female lateral habitus; photo by H. Goulet, CNC

Tremex columba male lateral habitus; photo by J. Orr, WSDA

Tremex columba male lateral habitus; photo by J. Orr, WSDA

Urocerus flavicornis female lateral habitus; photo by J. Orr, WSDA

Urocerus flavicornis female lateral habitus; photo by J. Orr, WSDA

Xeris sp. male lateral habitus; photo by J. Orr, WSDA

Xeris sp. male lateral habitus; photo by J. Orr, WSDA