Field Control of the Japanese Pine Sawyer, Monochamus alternatus (Coleoptera: Cerambycidae) Larvae by Steinernema carpocapsae (Nematoda: Rhabditida)

Abstract

Field trials were conducted in Shizuoka, Japan in 1987 for the control of Monochamus alternatus larvae infesting pine logs with Steinernema carpocapsae (str. Mexican). Differences in spray volume and application timing and rate were investigated. The upper surface of horizontally placed logs was applied with 20 million infective juveniles/m2 in a spray volume of 300, 600 or 1200 ml/m2. The 600 ml/m2 rate resulted in the highest larval mortality. Nematodes were applied on three different dates, Mar 17, 30 and Apr. 17 with the highest mortality of Japanese pine sawyer larvae being recorded for the April 17 application. This is attributed to the ambient air temperatures being above 12°C during the treatment. At the April 17 application, rates of 6 X 106 and 12 X 106 nematodes/m2 showed 69.2 and 72/2% mortality of larvae within the logs. Steinernema carpocapsae appeared to be an effective alternative to fenitrothion, for treatment of pine logs infested with the pine sawyer larvae. However, this nematode cannot prevent the spread of pine wilt disease and an integrated approach for pine sawyer suppression will still be needed