The tick Haemaphysalis cornigera is an important vector of Rickettsia japonica and other pathogens. Although the main hosts of H. cornigera include domestic animals and wild mammals, human infestations have also been reported. In Japan, H. cornigera has been sporadically recorded throughout the country, and its distribution is presumably linked to the movement of livestock, dogs, and humans. In autumn 2023, an adult H. cornigera was found for the first time in Ibaraki Prefecture during a survey of tick distribution. During the survey, 1,131 ticks of five species were collected, of which H. flava was the dominant species. One adult male H. cornigera was collected from the Ken-oh area of Ibaraki Prefecture, where only larvae of H. cornigera were recorded previously. The presence of this species over multiple years suggests that H. cornigera has established a local population. The extension of the distribution of H. cornigera in the Kanto area may be related to the expansion of wild mammals such as wild boar and deer. Continued monitoring of the distribution and risk assessment of H. cornigera as a vector of Rickettsia and other pathogens is essential.

High Pathogenicity Avian Influenza (HPAI) has spread among wild birds and spilled into poultry farms. HPAI viruses can be transmitted by various routes such as rodents or wild birds, and blowflies are also considered potential vectors for HPAI. Necrophagous flies can acquire various pathogens by ingesting contaminated carcasses or feces. We aimed to demonstrate that flies often feed on wild bird carcasses or feces by detecting avian DNA in blowflies collected around an HPAI-enzootic area. As a result, avian DNA was detected in 67 flies of 1,151 collected flies, representing nine bird species. This suggests that blowflies ingest various kinds of bird-derived material. In addition, avian DNA was detected in multiple species of blowflies. We conclude that blowflies could ingest viruses from infected bird carcasses or feces and consequently spread them elsewhere.

Mosquitoes were collected weekly using paired dry-ice traps in urban Tokyo from 2003 to 2022. A total of 27577 adults belonging to eight species in four genera were recorded, with Aedes albopictus and the Culex pipiens group being dominant. The annual number of Ae. albopictus increased from 2013 to 2018 and declined after vegetation around the trap site was cleared in winter 2018. To identify drivers of this long-term change, we modeled the summer abundance of Ae. albopictus (females and males separately) using a generalized linear model with a negative binomial distribution. Vegetation cover was the strongest predictor, showing a significant positive association with mosquito abundance. After accounting for vegetation, both daily average temperature and effective accumulated temperature were also significantly and positively associated with mosquito counts, whereas daily precipitation had no significant effect. These results suggest that vegetation growth at the study site from 2013 to 2018 provided a suitable resting habitat for Ae. albopictus, facilitating increased trap captures. Vegetation development, together with temperature-related factors, was therefore essential to the temporary rise in Ae. albopictus abundance observed during this period.