Penetration and Development of Allassogonoporus vespertilionis and Acanthatrium oregonense (Trematoda: Lecithodendriidae) Cercariae in Caddis Fly Larvae

Knight and Pratt (1955) described the life histories of Allassogonoporus vespertilionis Macy and Acanthatrium oregonense Macy, two lecithodendriid trematodes of bats. They reported that sporocysts of both flukes produced virgulate xiphidio-cercariae that developed into metacercariae in caddis fly larve. The metacercariae of A. vespertilionis encysted in the insect host whereas those of A. oregonense existed as unencysted, motile larvae. Adults of both species developed in hamsters which were fed metacercariae from naturally infected Limnophilus sp. larvae. While re-examining the life histories of these trematodes I have observed certain aspects of their development which were not reported by Knight and Pratt. These observations are presented in this report. They include the penetration of caddis fly larvae by the cercariae of both species and the encystment of Acanthatrium oregonense metacercariae during pupation of the insect host. An emendation of the original description of the motile metacercariae of A. oregonense is also given here.