A New Species of Apatania (Trichoptera, Limnephilidae) from Lake Biwa, with Notes on its Morphological Variation within the Lake

Descriptions of male, female and larva of Apatania biwaensis n. sp. from Lake Biwa are provided. This species is closely related to A. aberrans (MARTYNOV), the commonest Apatania species in streams in Honshu, but is distinctly distinguishable from it in male and female genitalia and larva. Data on morphological variation in male genitalia suggested that two morphologically distinguishable populations were recognized within the lake. A life history pattern of A. biwaensis is briefly shown based on the field and the laboratory observation. The species has an univoltine life cycle and aestivates as prepupa from spring to autumn.