Abstract: The Eurasian woodwasp, Sirex noctilio Fabricius is an important forestry quarantine pest in the world, which prefers to attack conifer. It is native to Eurasia and North Africa. However, over the last one hundred years, S. noctilio has been gradually introduced to New Zealand and Austria in Oceania, then to South American countries including Uruguay, Argentina, Brazil, and Chile and later to Canada, the US and South Africa. The woodwasp was first detected in Heilongjiang Province, in the northeast region of China in August, 2013, where it mainly attacked  Pinus sylvestris. A very strict mutualistic relationship exists between S. noctilio and the white rot fungus Amylostereum areolatum (Fr.) Boidin. S. noctilio’s terrible attacks on host tree are in fact the act of its distinctive oviposition: female insects drill 1-5 small holes in the host tree through the bark to the cambium, injecting phytotoxic venom together with the arthrospores of A. areolatum, and sometimes an egg, into the holes. Together, the three pathogenic factors, Sirex larvae, symbiotic fungus and phytotoxic venom, act to weaken or even kill the tree. Particular attention should be paid to this important forest invading pest to China on account of its potential economic and ecological importance to Chinese forest ecosystem. In this article we reviewed the current researches on the symbiotic relationship between the woodwasp S. noctilio and its fungal symbiont A. areolatum. A great number of research findings on this subject were compared and summarized, in which the trophobiosis between Sirex larvae and the fungus, the spread of the fungus by woodwasps, the population structure of the fungus and the collaborative damage effect of the Sirex venom and the fungus on host tree were discussed in details. We attempted to provide some reasonable suggestions for the future study and open new insight into the control on this pest effectively.

Key words: Sirex noctilio, fungal symbiont, Amylostereum, insect venom, mutualism, invasive species