Field Evaluation of Commercial Attractants and Trap Placement for Monitoring Pine Sawyer Beetle, Monochamus alternatus (Coleoptera: Cerambycidae) in Guangdong, China.

The pine sawyer beetle, Monochamus alternatus Hope (Coleoptera: Cerambycidae) is a serious insect pest of pine trees by vectoring the pine wood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) Nickle (Nematoda: Aphelenchoididae). Field studies were carried out during 2013-2015 in Guangdong (China) to evaluate the effectiveness of commercial attractants, effect of trap placement for monitoring M. alternatus, and temporal patterns of trap catch. Four commercial attractants, three trap placements (0, 1.5, and 3 m above ground) and different trapping distances (50, 200, 400, 600, and 900 m) from forest edge were evaluated for monitoring M. alternatus. Traps baited with a mixture of monochamol and plant volatiles captured significantly more beetles than traps baited with monochamol alone or plant volatiles alone. Traps set up at 1.5 m above the ground captured significantly more M. alternatus than those at 0 m and 3 m height. Based on 2,687 beetles trapped from two locations in 2013 and 2014, the female:male ratio was 2.9-4.1:1. The beetles' natural dispersal distance was approximately 100 m based on traps set at different distances from edge of the forest. Continuous monitoring over 38-wk period indicates the peak of adult M. alternatus emergence was between May and June within a year.