Diversity of natural enemies, especially parasitoids, captured by insect sticky traps in tea fields

We surveyed natural enemy composition (especially Hymenoptera parasitoids), fauna, and seasonal prevalence of their occurrences using insect sticky traps (SE trap: a commonly used pheromone trap) set on tea trees in six commercial tea fields (IPM and conventional control in each area) in three areas of Shizuoka prefecture, Japan. We recognized 13 to 16 families of Hymenoptera parasitoids, Dipteran natural enemies (Cecidomyiidae, Tachinidae, and Syrphinae), and three species of Coccinellidae in Makinora fields. In Kakegawa fields, we identified at least 15 families of Hymenoptera parasitoids, Dipteran natural enemies, and six species of Coccinellidae. In Kikugawa fields, we identified at least 11 families of Hymenoptera parasitoids, Dipteran natural enemies, and three species of Coccinellidae. The total numbers of families of Hymenoptera parasitoids recognized by this survey was 18, with 8 species of Coccinellidae identified. Classification groups of the parasitoids that had the largest number of captures were Arrhenophagus albitibiae, Pteroptrix orientalis, Encarsia smithi, Aphidiidae, and Ichneumomonidae. Comparison of IPM and conventional control fields showed that the number of captured A. albitibiae and P. orientalis in an IPM field was larger than that in a conventional control field. However, for most of the parasitoids, no difference was observed between the treatments; therefore, the effect of applied pesticides on the parasitoids was not clear. The number of Thomsonisca indica, Elasmus sp., and Ichneumomonidae captured by SE traps on tea trees was larger than those captured by yellow sticky traps inside the tea tree canopy. SE traps were more useful for the capture of the above parasitoids. Seasonal prevalence patterns of the major parasitoids were similar to those captured by yellow sticky traps. The peaks of the capture of Syrphinae adults, which is the natural enemy of Toxoptera aurantii, were observed between April-May, June-July, and September-October, which corresponds to the growing seasons of tea shoots, with the peak in autumn as the highest.