Detection and Identification of the Invasive Sirex noctilio (Hymenoptera: Siricidae) Fungal Symbiont, Amylostereum areolatum (Russulales: Amylostereacea), in China and the Stimulating Effect of Insect Venom on Laccase Production by A-areolatum YQL03

The Eurasian woodwasp Sirex noctilio F. was first detected in Daqing, Heilongjiang Province, in the northeast region of China in 2013. Here, we investigated the Sirex noctilio's fungal symbiont, Amylostereum areolatum, and insect venom produced in its acid (venom) gland. Overall, seven out of 10 fungal isolates obtained from the mycangia of 10 adult Sirex noctilio females in this study were identified as Amylostereum areolatum. The remaining three isolates were identified as Trichoderma viride, Verticillium dahlia, and Geosmithia pallida, which were probably contaminants that entered during the mycangia-spore extraction procesSirex The enzyme activity bioassay showed that the level of laccase activity of Amylostereum areolatum YQL03 in liquid medium is prominently enhanced by insect venom, but was relatively low when venom was not available as an inducer. This study confirms the presence of Amylostereum areolatum in Sirex noctilio specimens from ChinAmylostereum The putative heat-stable factors identified in Sirex noctilio venom may contribute novel information about the pathogenic mechanism of the Sirex noctilio-Amylostereum areolatum pine-killing pest complex on host treeSirex