Chinese TortrixCydia trasias(Lepidoptera: Olethreutidae): Suppression on Street-Planting Trees by Mass Trapping with Sex Pheromone Traps

Abstract

Mass trapping to control the Chinese tortrix Cydia trasias (Meyrick) by removal of males using sex pheromone traps was evaluated in three plots of Chinese scholar-trees Sophora japonica L. in Beijing, China, in 2000. The traps, baited with 0.25 mg C. trasias synthetic sex pheromone (60% E8, E10-dodecadienyl acetate (E8, E10–12:Ac) and 40% E8, E10-dodecadien-1-ol (E8, E10–12:OH), were deployed in the trapping plots at a density of one trap per two trees. The trees in all plots were planted ≈4.5 m apart along pedestrian paths. In the trapping plot on Zhichun Road, the mating rates of caged virgin females were reduced by 70.65% and 66.48% when compared with the control plots during the overwintering- and second-generation moth flight-period, respectively. Population densities of hibernating larvae on tree trunks during the third generation were significantly lower than those of the overwintered generation (the third generation of the previous year). Tunneled petioles caused by first- and second-generation larvae were reduced by 47–79% and 62–81%, respectively. Bored seed pods caused by third-generation larvae were reduced by 87–96%. Higher initial populations in the trapping plot on North Shuangyushu Road may have led to the higher observed petiole and seed pod injuries than in the other two plots during the second and third generations. Thus, male removal using sex pheromone traps is a promising means of effectively controlling C. trasias on street-planted Chinese scholar-trees.