Monitoring Pseudaulacaspis pentagona (Targioni Tozetti) (Hemiptera: Diaspididae) and parasitoids in tea fields using sex pheromone traps

Abstract

For 3 years we investigated the insects captured by laying synthetic sex pheromone traps set to lure the white peach scale, Pseudaulacaspis pentagona (Targioni Tozetti), in the tea fields of Shizuoka Prefecture, Japan. Adult males of P. pentagona, and natural parasitoids and predators of these scale insects, such as Arrhenophagus albitibiae Girault; Pteroptrix orientalis (Silvestri); Thomsonisca amathus Walker; and Cecidomyiidae, including Dentifibula sp., were captured in traps. The ratio of the captured insects in the pheromone traps to blank traps ranged from 4.4–6.0 for P. pentagona, 323–685 for T. amathus, 0.8–1.5 for A. albitibiae, 0.9–1.5 for P. orientalis, and 0.8–1.2 for Cecidomyiidae. Statistical analysis revealed that the sex pheromone traps for P. pentagona significantly attracted only scale insects and the parasitoid, T. amathus. The pheromone appeared to act as a kairomone against the parasitoid. Moreover, there was a significant positive correlation between the number of captured T. amathus and P. pentagona individuals per generation. The capture peak date in each generation of both species coincided in approximately half of the generations, indicating the synchronous occurrence of both species.