Aerobic organisms generate reactive oxygen species (ROS) through respiration, whereas plants produce ROS also during photosynthesis. Although ROS are crucial redox signaling agents, excess production due to external factors (e.g., solar ultraviolet [UV] radiation and radiant heat) can cause cell damage. Therefore, to withstand oxidative environments and maintain homeostasis within the body, organisms are equipped with enzymatic antioxidant mechanisms that control ROS concentrations. Nevertheless, strong external oxidative stress can overwhelm the capacity of enzymatic antioxidant protection systems. Plants synthesize carotenoids, which are well-known scavengers of ROS, and deploy them to the thylakoid membranes of chloroplasts, where they function as a non-enzymatic antioxidant protection system. Animals, lacking the ability to synthesize carotenoids de novo, rely on protective compounds produced by plants. Recent studies have revealed significant negative effects of solar UV-B radiation and radiant heat on plant-dwelling mites, highlighting the direct impact of antioxidant protection on their dynamics and interactions. However, the specific roles and effects of each protection mechanism are unclear. This review discusses the protective mechanisms used by spider mites and phytoseiid mites against oxidative stress induced by heat and UV-B irradiation, focusing on antioxidant enzymes and carotenoids.

A survey of tick species collected from wild boars (Sus scrofa) and sika deer (Cervus nippon), captured for vermin control and by flagging, was conducted in Ashikaga City, Tochigi Prefecture, Japan, in 2021 to reveal the reasons of tick-bite cases predominantly caused by Amblyomma testudinarium in the region. The results showed that the collection of A. testudinarium per wild boar was 10 times higher than that from sika deer, with the highest in April and May, based on the number of nymphs and adults, but the number of A. testudinarium collected by flagging was overly small. For Haemaphysalis longicornis, only a few ticks were collected per wild boar in early spring, whereas in the case of sika deer, the infesting numbers increased in May, reaching a maximum in July (based on adult females), along with stable collection by flagging from spring to autumn. The above-mentioned results reveal that A. testudinarium as the dominant species causing tick-bite cases closely associated with wild boars entering residential properties in the village vicinity mountainous areas in Ashikaga City. For H. longicornis, sika deer acting as a reservoir to bring and stable collection by flagging would be the reasons for small numbers but persistent tick bite cases in this area. In addition, several types of ticks were revealed to infest wild boars and sika deer even in winter, including species mainly reported in southwestern Japan.

A new water mite species from Japan, Feltria (Feltriella) itoae sp. nov., is described. One male of this species was collected from a river weir in Hokkaido. Although F. (F.) itoae is similar to the male of Feltria (Feltriella) menzeli Walter, 1922, the new species can be distinguished from F. (F.) menzeli by the longer and broader dorsal plates on both sides of the anteromedial plate, and the posterior plate reaching the end of the dorsum.