Evidence of sexual attraction by pheromone in the cedar web-spinning sawfly

Abstract

AbstractThe cedar web-spinning sawfly, Cephalcia tannourinensis Chevin (Hymenoptera: Pamphiliidae), is a pest that has been causing serious damage to cedar (Cedrus libani) forests in Lebanon since 1990. The existence of a sex pheromone was shown in field experiments in a cedar forest in Lebanon and in laboratory tests in olfactometers with and without airflow. More males were caught in traps baited either with virgin females or with a hexane extract of the whole female body than in traps baited either with males alone or with mixed males and females. Male and female C. tannourinensis were active during the day. Mating and pheromone production were observed to occur during midday hours (1000–1400) in the field and under laboratory conditions. Olfactometer tests with extracts prepared from different body parts of the female indicated that the pheromone is produced in the abdominal region, and tests with different dilutions of female extract showed that the male response is dose-dependent.