The sweet potato weevil, Cylas formicarius（Fabricius）（Coleoptera: Brentidae）, was detected in October 2022 in Hamamatsu City, Shizuoka Prefecture, Japan, with eradication completed in November 2024 through emergency pest control under the Japanese Plant Protection Act. To determine its origin, we analyzed genetic variation in the mitochondrial cytochrome c oxidase subunit I（mtCOI）gene of 2,024 individuals from 20 countries, including Japan. In total, 158 mtCOI haplotypes were identified worldwide, with 94 detected in 1,729 individuals from 47 geographical populations in Japan. A maximum likelihood phylogenetic tree revealed 11 clades（Clades A–K）, with Japanese haplotypes distributed among three clades: Clades A（Nansei Islands and Taiwan）, C（Ogasawara Islands, China, Hong Kong, Fiji, and Australia）, and J（Minamitorishima Island and the Philippines）. All 24 individuals collected from 10 sites in Hamamatsu City shared the same haplotype within Clade C. These results suggest that the invasive population of C. formicarius, which occurred in Hamamatsu City, originated from a single source, possibly the Ogasawara Islands or another country.

Alternative control measures such as spiracle blockers can reduce the frequency of pest population exposure to pesticides and delay resistance development; however, population decline may in itself cause resistance allele fixation through genetic drift. We conducted a release experiment with two-spotted spider mites, Tetranychus urticae Koch, in strawberry fields in Shizuoka and Nara prefectures to examine the influence of spiracle blockers （sorbitan fatty acid esters） on the frequency of the etoxazole resistance allele （CHS1; I1017F）. F2 adult females from resistant and susceptible strains crossed at a 1 : 9 ratio were introduced, followed by two consecutive control rounds using either a spiracle blocker or etoxazole at their registered concentrations. Resistance allele frequencies were measured via quantitative PCR. The resistance allele frequency increased in Shizuoka only after using etoxazole but increased to approximately 80% in Nara after the first round regardless of the control measure used. The population density dropped to one mite per compound leaf after the first round, suggesting a genetic bottleneck. The estimated initial allele frequency in the F2 population was 6%, and etoxazole was effective only once, highlighting the need for risk avoidance （e.g., switching to other control measures） when resistance alleles are still rare.

In recent years, widespread damage caused by biotype B of the stone leek leafminer, Liriomyza chinensis（Kato）（Diptera: Agromyzidae）, has become an issue in Welsh onion fields throughout Ibaraki Prefecture. This study aims to evaluate the efficacy of granular insecticides in controlling L. chinensis in Welsh onion fields harvested in early autumn. Specifically, we applied either cyantraniliprole-thiamethoxam granules（6 kg/10 a）or dinotefuran granules（9 kg/10 a）to the base of the plants in late August, and compared their effectiveness to a non-granule control. Although all treatments showed an increase in the number of flies from mid to late September, the percentage of damaged leaves in the groups treated with granules was lower than that in the non-granule control. Furthermore, the effectiveness of dinotefuran was equal to or greater than that of cyantraniliprole-thiamethoxam. These results suggest that dinotefuran is a lower-cost alternative with saved times of usage of insecticide components, in late August on Welsh onions harvested in autumn.

Stem borers are important insect pests that cause serious damage to trees by their larvae boring into the interior of trees. Although chemical control using aerosol spray insecticides is recommended for stem-boring insect pests, the chemicals often do not reach the larvae hidden in complicated pores, thereby reducing their extermination effectiveness. Because the pores are semi-closed spaces, volatile insecticides are expected to reach the larvae hidden deep within the complex pores. Therefore, we conducted a model test to demonstrate the effectiveness of extermination of the stem boring moth larvae, Endoclita excrescens（Butler）（Lepidoptera: Hepialidae）, hiding deeply in the holes where the insecticide spray cannot be directly reached using AITC containing agents, which have insecticidal effects and high volatility, and the non volatile insecticide containing clothianidin and fenpropathrin. The results showed that the AITC preparation had a significantly higher extermination effect on moth larvae than the non-volatile insecticidal preparation or the control（no insecticide preparation）. This suggested that volatile insecticides could effectively exterminate borer insect pests in areas that cannot be reached by chemical solutions.

A camera-trapping system developed for photographing perching Sympetrum dragonflies using passive photosensors is expected to support the biodiversity monitoring and evaluation of rice paddy fields. However, considerable time and labor was required in order to visually check the massive number of captured photographs to determine whether the dragonflies were correctly captured in them. In this study, automatic image classification using a deep-learning artificial-intelligence （AI）model was applied to the photographs captured by camera traps set in rice paddy fields in eastern Fukushima prefecture. The results show that the AI model can accurately detect and classify photographs containing a Sympetrum dragonfly, and that the estimated detection frequency based on the AI image classification is associated with the relative density of Sympetrum dragonflies directly observed in the fields. This suggests that automation by combining camera trapping and AI image classification is promising for monitoring Sympetrum dragonflies in the study area.