Parasitism of water mites (Acari: Hydrachnidiae) on caddisflies (Insecta: Trichoptera) in Hokkaido, Niigata, and Yamanashi Prefectures in Japan

Abstract

In most cases, during the larval stage of their life cycle, prostigmatic aquatic mites parasitize the body surface of aquatic insects (Smith, 1988). Studies on water mites’ parasitism on aquatic insects in Japan primarily began as studies of biological control against malaria (e.g., Miyazaki, 1933). Therefore, most studies on water mite parasitism in Japan focus on dipteran hosts (Yamada, 1918; Miyazaki, 1933, 1935, 1936, 1945, 1947; Uchida and Miyazaki, 1935; Imamura, 1950c, 1951b, 1951d, 1952a; Hirabayashi and Fukunaga, 2007). Studies on parasitism on other insect taxa are rather limited: Hemiptera (Masuda, 1934, 1942; Imamura, 1952b; Nagasawa et al., 2008; Morimoto, 2012; Abé et al., 2015, 2017), Coleoptera (Masuda, 1934, 1935a, 1935b, 1942), Odonata (Miyazaki, 1936; Imamura, 1950a, 1951a, 1951c; Imamura and Mitchell, 1967; Kobayashi and Toda, 2005), Trichoptera (Nagasawa and Abé, 2015), and Plecoptera (Imamura, 1950b; Nagasawa and Abé, 2015). Recently, the authors had an opportunity to examine several water mite larvae attached to adult caddisflies collected in Hokkaido, Niigata, and Yamanashi Prefectures. Accordingly, this paper aims to obtain knowledge concerning the host–parasite correspondence and parasitic nature between water mites and caddisflies in these three districts.