Mating Behavior of Physolimnesia Australis (Acari, Limnesiidae), a Non-parasitic, Rotifer-eating Water Mite from Australia

Abstract

The diversity of sperm transfer behavior shown by water mites (Acari, Hydrachnidia) is among the highest in the Arthropoda. However, sperm transfer has been described in fewer than 10% of water mite genera, all of them being Holarctic or cosmopolitan taxa. Here I describe mating behavior in Physolimnesia australis (Halik 1940), the sole representative of an Australian genus. P. australis is unusual in having larvae that do not parasitize insects, and in including rotifers in its diet. The highly dimorphic P. australis male responds to female presence by taking up an "embrace" posture in which he orients his opisthosoma and legs Ill toward approaching females. The female is caught in the embrace and her legs IV are secured by the modified tips of the male's legs IV. The male deposits a glutinous mass on the female's back, which she grooms towards her genital opening after being released. This mode of transfer differs from members of the confarnilial genus Limnesia Koch 1836 in which males and females do not pair.