Abnormal development of a filarial worm, Brugia patei (Buckley, Nelson and Heisch), in a mosquito host, Anopheles labranchiae atroparvus van Thiel

Abstract

The morphology of abnormal development of the filarial worm Brugia patel in a mosquito host, Anopheles labranchiae atroparvus, is described. Development was very variable, from little growth beyond the microfilarial stage to the complete development of two infective stage larvae in one mosquito. The majority of larvae developed beyond the microfilarial stage but integrated differentiation did not occur. In the most bizarre larval development, the intestinal and the rectal cells prolapsed and then attempted to differentiate outside the body of the filarial larva. It is concluded that the abnormal development of the filarial larvae in this mosquito host is due to the host reaction elicited by the developing larvae, apparent as melanisation 48–78 hours after ingestion by the mosquito, often localised specifically over the excretory and anal vesicles.