Research On Occurrence And Control Techniques Of Pine Sawyer In Qinzhou

The pine sawyer (Monochamus alternatus Hope) is a vectorinsect of pine wood nematode(Bursaphelenchus xylophilus) which can cause pine wilt disease and serious economic loss. The life history,occurrence,natural enemies and control measures of this insect were investigated in Qinzhou, Guangxi during2009-2011. The main results are summarized as follows:(1) Most pine sawyer populations had three generations every two years and the rest had two generations a year. Three emergence peaks occurred in mid-April to mid-May, mid-July to early-August, and mid-May to early-June, respectively, for the former populations while two peaks in early April to mid-May and mid-July to mid-August, respectively, for the latter.The generations heavily overlapped.(2) The percentage of notch grooves with eggs increased with the increase of the number of ovipositing adults, with95%being the highest. Adults preferred smooth to rough barks for oviposition.(3) Damage by pine sawyer was more serious to the stressed and weakenedtrees than to the healthy ones. Masson pine forest was subject to more damage than mixedpine forest.(4) Beauveria bassiana, Tetriguslewisi, Cryptalausberus and Dastarcus helophoroides were found to be the main natural enemies of the pine sawyer in Qinzhou. Compared to trapping methods, biological control using natural enemies appeared to be advantageous.