A new pattern of parasitism in water mites (Hydrachnidia)? An insight into their relationships with pupae of caddisflies (Trichoptera).

To date, relatively few data have been available regarding the parasitism of water mite larvae on caddisflies; most available information relates to the adult stadia, fewer to caddisfly larvae, with just single references to pupae. The present paper examines the occurrence (phoresy and parasitism) of Piona stjordalensis larvae (119 individuals) on the larvae and pupae of Mystacides longicornis. It is possible that water mite larvae exhibit a new type of parasitism on caddisflies, with two consecutive parasitic larval stadia: one on the pupa, the other on the imago.