Sirex atricornis

Taxonomy

Family: Siricidae
Subfamily: Siricinae
Genus: Sirex Linnaeus, 1760
Species: Sirex atricornis Kjellander, 1945
Common names: none

Background

Sirex atricornis is a rare species known only from northern Europe (Schiff et al. 2012).

Diagnostic characteristics

See Sirex for genus-level diagnostic characteristics.

Females:

May be confused with

Sirex atricornis can be distinguished from the similar Nearctic species S. nitidus only by the shape of the second annulus of the ovipositor (Schiff et al. 2012).

Morphological and geographical variation

none recorded

Host associations

Sirex species feed on trees of Pinaceae and Cupressaceae. Sirex atricornis is recorded from Pinus sylvestris (Viitasaari 1984) and likely feeds on other Pinus spp. (pine) (Schiff et al. 2012).

Life history

Female Sirex harbor symbiotic basidiomycete fungus in abdominal glands called mycangia. During oviposition, the site is inoculated with the fungus (Amylostereum spp.), which begins to decompose the surrounding wood. Larvae feed on the fungus, and in the process bore galleries through the wood (Schiff et al. 2012).

Larvae are creamy white and grub-like in appearance with a dark head capsule. As with adults, larvae possess a short dorsal horn on the posterior end of the body. The larvae bore galleries into wood, feeding until pupation and subsequent emergence. Throughout this process, the larvae use their horn to pack the tunnel behind them with sawdust. Emergence holes are perfectly circular. The fungal symbiont is carried in specialized organs in female larvae that develop into the mycangia after metamorphosis (Schiff et al. 2012).

The specific biology of Sirex atricornis is unknown.

Distribution

World: Sirex atricornis is found in northern Scandinavia, Finland, and Russia (Schiff et al. 2012).

North America: not recorded

Map data from: GBIF.org (26 June 2019) GBIF Occurrence Download Sirex atricornis

Details about data used for maps can be found here.

Specimens of this species not available for imaging.