Host-parasite relationships of wuchereria bancrofti and mosquito hosts, culex pipiens L and aedes caspius pallas

ABSTRACT

The reciprocal deleterious effects of both the mosquito host and its parasite were reported. Anatomical and histological examinations of mosquitos revealed minor differences in the general structure of the foregut of either species. However, the cibarial pump of Ae. caspius lacked a cibarial armature and damage inflicted to some of the microfilariae [mf] ingested by this mosquito was not mechanical. In contrast, the cibarial armature of Cx. pipiens consisted of 24 delicate teeth, which did not seem to affect ingested mf. The peritrophic membrane [pm] did not constitute a significant barrier to mf, migrating through the midgut wall of either mosquito. Traversing mf perforated the pm and displaced the basement membrane. Within the thorax of Cx. pipiens, the parasite completed its development synchronously. In contrast, mf ingested by Ae. caspius did not develop beyond the sausage stage and many of these larvae were vacuolated. In both mosquitos, parasitized thoracic muscle fibers were tunneled and only in Ae. caspius, their nuclei were pyknotic. No worm encapsulation or melanization was observed in either mosquito