Analysis of Genetic Variation and Phylogeny of the Predatory Bug, Pilophorus typicus, in Japan using Mitochondrial Gene Sequences

Pilophorus typicus (Distant) (Heteroptera: Miridae) is a predatory bug occurring in East, Southeast, and South Asia. Because the active stages of P. typicus prey on various agricultural pest insects and mites, this species is a candidate insect as an indigenous natural enemy for use in biological control programs. However, the mass releasing of introduced natural enemies into agricultural fields may incur the risk of affecting the genetic integrity of species through hybridization with a local population. To clarify the genetic characteristics of the Japanese populations of P. typicus two portions of the mitochondrial DNA, the cytochrome oxidase subunit I (COI) (534 bp) and the cytochrome B (cytB) (217 bp) genes, were sequenced for 64 individuals collected from 55 localities in a wide range of Japan. Totals of 18 and 10 haplotypes were identified for the COI and cytB sequences, respectively (25 haplotypes over regions). Phylogenetic analysis using the maximum likelihood method revealed the existence of two genetically distinct groups in P. typicus in Japan. These groups were distributed in different geographic ranges: one occurred mainly from the Pacific coastal areas of the Kii Peninsula, the Shikoku Island, and the Ryukyu Islands; whereas the other occurred from the northern Kyushu district to the Kanto and Hokuriku districts of mainland Japan. However, both haplotypes were found in a single locality of the southern coast of the Shikoku Island. COI phylogeny incorporating other Pilophorus species revealed that these groups were only recently differentiated. Therefore, use of a certain population of P. typicus across its distribution range should be done with caution because genetic hybridization may occur

Insecticidal effect of high concentrations of spreader and adjuvant on cotton aphid Aphis gossypii Glover (Homoptera: Aphididae)

The cotton aphid (Aphis gossypii Glover) (Homoptera: Aphididae) is an important insect pest worldwide because it infests a wide variety of crops and develops insecticide resistance. Spiracle-blocking insecticides are often effective against aphids that have developed insecticide resistance. In this study, the insecticidal effects of a spreader, Mairino® and an adjuvant, Approach® BI, on A. gossypii were investigated to search for new spiracle-blocking insecticides. We used the standard, and concentrations of the products and found highly significantly corrected mortality rates at 10× dilution of the spreader and 10×, and 100× dilutions of the adjuvant. Specifically, the adjuvant had a highly significant effect on the mortality rate of A. gossypii, and since it did not show phytotoxicity, it might be practical for use as an insecticide. However, to utilize spreaders and adjuvants as insecticides, it is necessary to study their phytotoxicity in more detail

Optimal rearing medium for the population growth of the predatory mite, Amblyseius swirskii (Athias-Henriot) (Acari: Phytoseiidae)

【Background】 The successful rearing of predators or parasitoids is one of the most important elements in biological control programs. The dried fruit mite, Carpoglyphus lactis (L.), can be used as an alternative prey for the phytoseiid predatory mite, Amblyseius swirs0kii (Athias-Henriot). 【Main body】This study aimed to evaluate the suitability of 3 different diets for C. lactis when rearing A. swirskii: brown sugar, baker’s yeast, and the mixture of brown sugar and baker’s yeast along with 3 initial predator:prey ratios (1:7, 1:12, and 1:20). After 30 days, both the baker’s yeast and the mixture of brown sugar + baker’s yeast diets resulted in the highest predator densities (40.5 times increase at an initial predator:prey ratio of 1:20, with the baker’s yeast diet), whereas the mixture diet produced the highest density of prey. The brown sugar resulted in the lowest number of predator and prey mites. This may be due to lower feeding and predation rates of the prey and the predator mites on the brown sugar medium since its relative moisture content and adhesiveness inhibits mite movement. The final predator:prey ratio was also highest on the baker’s yeast diet.【Conclusions】This study demonstrated that the population growth of A. swirskii was the highest when C. lactis was reared on baker’s yeast

ITER TFコイル第二製造ライン初号機の完成

日本におけるITER-TFコイルの２つの製造ラインのうち、第二製造ラインにおいても、初号機が完成した。本結果を報告すると共に、日本におけるITER-TFコイルの製作の進捗についても、簡明に報告する。27th International Conference on Magnet Technology（MT27