We investigated the effect of a barrier with lapel-shaped folded structure on reducing dispersion of Scepticus griseus (Coleoptera: Curculionidae) adults, in order to establish a method for reducing their invasion to crop fields. In double-framed field plots, we installed an inner frame with or without a lapel-shaped folded structure facing outward at 40°to the vertical surface. The weevil adults were released between the inner frame and the outer frame then investigated after a certain period of time. Invasion into the inner frame with the lapel-shaped folded structure was significantly reduced compared to the inner frame without it, indicating that the barrier with a lapel-shaped folded structure is promising as a physical control method to reduce migration of this weevil.
We investigated the abundance and species composition of thrips and Orius spp. on the flowers of two insectary plants; Scaevola aemula R. Br. and Tagetes patula L. cultivated in planters in urban areas of Tokyo. Frankliniella occidentalis (Pergande), Frankliniella intonsa (Trybom), Thrips hawaiiensis (Morgan), and Thrips tabaci Lindeman were the dominant pest thrips on S. aemula. Neohydatothrips samayunkur (Kudo) were the dominant species on T. patula, with peak abundance in mid-November. Orius strigicollis (Poppius) and Orius minutus (L.) were found on both plants. Orius sp. nymphs were also captured from S. aemula. These results suggest that the two plant species are effective candidates of insectary plants to conserve Orius species and to enhance their function of controlling pests even in an urban area.
The parasitoid Encarsia smithi found in Japan comprises two phylogenetic groups. Type I was introduced from China in 1925 to control the orange spiny whitefly, Aleurocanthus spiniferus, in citrus orchards. The other phylogroup, type II, was accidentally introduced in ca. 2004, and has recently been found in tea fields infested with the tea spiny whitefly, A. camelliae. To clarify ecological characteristics of the two groups on the host A. camelliae, we developed the rearing experiment in a laboratory scale by using A. camelliae-infested tea seedlings. Although there was no statistically significant difference, we observed that type II tended to have higher number of offspring than type I, which was opposite to the result when using A. spiniferus-infested citrus seedlings in our previous study. Emergence pattern of each group, on the other hand, was similar to that in the previous study; females emerged earlier than males in type I, while females and males emerged almost at the same time in type II.
ナシ園に生息するニセラーゴカブリダニの土着天敵としての有効性を調べるために，ナシの害虫であるナミハダニとカンザワハダニを捕食したニセラーゴカブリダニからの両種ハダニの DNA 検出法の開発を試みた。その結果，蛍光修飾したプライマーと DNA 解析装置を用いて両種を高感度に検出することが可能であった。本手法を用い，茨城県のナシ園に生息するニセラーゴカブリダニから，本カブリダニが捕食したと考えられるナミハダニとカンザワハダニの PCR 増幅断片が確認された。