Sirex cyaneus

Fabricius, 1781

blue horntail

Sirex cyaneus, commonly known as the horntail, is a of woodwasp in the . to forests in Alberta, Canada, reach approximately 2 cm in length. The species serves as a for including Rhyssa persuasoria and Ibalia leucospoides, which have been studied for potential applications.

Sirex cyaneus by Emma Wahlberg. Used under a CC BY-SA 3.0 license.

Sirex cyaneus female by Whitney Cranshaw. Used under a CC BY 3.0 us license.

Pronunciation

How to pronounce Sirex cyaneus: //ˈsaɪ.rɛks saɪˈeɪ.ni.əs//

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Images

Habitat

Forests in Alberta, Canada. Associated with coniferous trees; bore into wood.

Distribution

Canada: Alberta, Labrador. Presence recorded in Austria (AT); doubtful record in Belgium (BE).

Host Associations

Pinus radiata - not a direct ; related to contextSirex juvencus (now Sirex noctilio) is destructive to Pinus radiata plantations in New Zealand; of S. cyaneus were suggested for introduction there
Larix europaea - associated with collection localityLarch trees present at Oxford locality where collections were made; not confirmed as direct for S. cyaneus

Life Cycle

bore into wood. Parasitized larvae make final just under and approximately parallel to bark surface when attacked by Ibalia leucospoides.

Behavior

are wood-borers. possess an for drilling into wood to lay .

Ecological Role

for Rhyssa persuasoria and Ibalia leucospoides. Suggested as a source for agents against Sirex noctilio (formerly S. juvencus) in New Zealand.

Human Relevance

Serves as a research subject for ; reared from this have been considered for introduction to New Zealand to control Sirex noctilio, a destructive pest of pine plantations.

Similar Taxa

Sirex noctilio (formerly S. juvencus)Closely related ; S. noctilio is a major pest of pine plantations in New Zealand and elsewhere, while S. cyaneus has been used as a source of for of S. noctilio
Sirex juvencusSynonym or former name for S. noctilio; explicitly mentioned in historical literature as the target for using from S. cyaneus

More Details

Parasitoid Biology

Two attack S. cyaneus: Rhyssa persuasoria (ectoparasitic, one-year ) and Ibalia leucospoides (endoparasitic, two-year life cycle). Rhyssa pierces solid wood with its to lay near full-fed or . Ibalia oviposits in young larvae using existing Sirex bores. The different targeted prevent between these two parasitoid species.

Historical Research Context

Studies conducted at Oxford and Farnham House Laboratory in 1928 documented the biology of these . Rearing programs were established to ship parasitoids to New Zealand for purposes. An error in the original 1928 publication incorrectly stated that larch (Larix europaea) is to Britain; it is actually Palaearctic but not to Britain.