Exsheathment and Migration of Microfilariae of

Abstract: Observations were made on the exsheathment and migration of microfilariae of Brugia malayi in mosquitoes. In Aedes togoi and Aedes albopictus, the microfilariae ingested into the midgut commonly exsheathed and migrated to the thorax. The larvae which moved to the thorax in the former mosquito developed to the 3rd stage, but in the latter the larvae did not grow even to the 2nd stage. The microfilariae in Armigeres subalbatus also cast off the sheath in the stomach at a moderate rate, whereas, those which moved to the thorax were small in number, and did not develop any further. On the other hand, in Culex pipiens pollens, most of the microfilariae did not exsheathe and died without migrating to the thorax. Therefore, it can be said that the exsheathment of microfilariae of B. malayi in the midgut of mosquitoes has a close relation with their migration to the thorax. Malayan filariasis is found in the South-and-East Asian countries, such as Ceylon