Studies on Filariasis. II. Brugia pahangi: the Escape of Infective Larvae from the Mosquito

Abstract

1. Aedes togoi infected with B. pahangi were allo'ved to engorge on mice, to probe (but not to feed) on live and on dead mice, and to engorge on blood and on honey from cotton-wool pledgets. The number of worms in the mosquitoes after feeding or probing was compared with the number in unfed controls.2. These experiments suggest that increased l?aemocoelic pressure as a result of the insect's gut filling with blood does not trigger the escape of nematodes from the mouthparts.3. Host factors such as moisture, warmth, and chemical stimuli in the blood do not appear to be of any real significance.4. The bending back of the labium, as the fascicle is driven into the skin, seems to be highly important. Some factor (or factors) associated with the movement of the mouthparts appears to be directly and chiefly responsible for the egress of infective filariae from the mouthparts of the mosquito blood-feeding on its host.