Tree Killers: Sirex Wasp
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Name
- Common English name: Sirex Wasp
- Other names: Sirex woodwasp
- Latin (scientific) name:Â Sirex noctilio
History in Canada
- introduced from Eurasia in wood packing material
- first detected in New York State in 2004
- found in southern Ontario in 2005
- now known also in Michigan and Pennsylvania
Biology
- life cycle takes one to two years
- adult wasp has a dark body and wings, and orange-brown legs
- adult size is quite variable: 9-36 mm (3/8-1 ½ in)
- adults are strong fliers and can travel several kms after emerging
- female lays eggs in stems along with toxins and a symbiotic fungus
- larvae are whitish grubs that grow to 30 mm long (1 ¼ in) and have a distinctive tail spike
Impact on Trees
- attacks living trees
- prefers Pine, but will also attack Spruce, Fir, and Douglas Fir
- causes foliage to wilt and turn yellow
- in the Southern Hemisphere, the wasp has caused 80% mortality of pines where it is established
What can be done to control this tree killer?
- a parasitic nematode (Deladenus siricidicola) can be used to infect larvae that then develop into sterile females
- sterile females spread the nematode when they attempt to lay eggs
- several species of parasitic wasp that are native to North America have been introduced into South America as control agents there and these should help control the wasp here
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