Studies on Scleroderma guani to Control the Pine Sawyer Beetle, Monochamus alternatus

Abstract

After clear-cutting dead pine trees caused by the inewood nematode (PWN), Bursaphelenchus xylophilus, some remained as dead branches and stumps which were bored by larvae of pine sawyer beetle (PSB), Monochamus alternatus, which could not be removed from the forest, constitute a potential source of inoculum. Several natural enemies for controlling PSB were found, in Dongshanqiao district near Nanjing. Scleroderma guani is one of the most successful natural enemies that parasitizes the larvae of PSB and is easy to reproduce. Three hundred thousand larvae of PSB were collected in the forest annually for the purpose of massive rearing of S. guani in the lab. The studies of the biology, reproductive methods, release techniques and control effect of the larvae of PSB by S. guani were investigated. Mass rearing of S. guani in the lab resulted in 13 million female adults of S. guani for 0.3 million larvae of PSB annually from 2004–2006. S. guani was released to control the larvae of PSB in the same and other affected areas by PWN. The dead pine trees were significantly reduced in the test area. Both collecting the larvae of PSB and releasing the adults of S. guani were a good and ecological way to control PSB and PWN in a large area because of its low risk to humans and to the environment.