Studies on filariasis VI : The encapsulation of Brugia malayi and B. pahangi larvae in the mosquito, Armigeres subalbatus

In the experimental infection of Brugia malayi to two strains of Armigeres subalbatus, 406 and Rendaiji strains, 58.2% and 63.3% of the total number of filarial larvae were encapsulated mostly in the abdominal haemocoel 24hr after infective blood meal respectively. The encapsulation was also observed in the mid-gut and thorax, but with fewer larvae and in less intensity. On the contrary, smaller numbers of B. pahangi larvae, 2.8% and 17.7% in 406 and Rendaiji strains respectively, were encapsulated in this species of mosquito which is known susceptible to the parasite. It was indicated that the encapsulation of B. malayi larvae in the haemocoel of Ar. subalbatus was linked in a restricting factor in the larval migration from the haemocoel into the thorax.