Anthropophagy and aggregation behaviour of the sandfly Phlebotomus argentipes in Sri Lanka

The visceral leishmaniasis (VL) vector Phlebotomus argentipes Annandale & Brunetti is widely distributed throughout the Indian sub-continent and S.E. Asia. The absence of VL in areas such as Sri Lanka has been attributed to the zoophilic nature of P.argentipes, since they were not recorded biting man. Field studies on P.argentipes were undertaken in the central highlands of Sri Lanka, near Kandy, in May 1988. Male sandflies outnumbered females on cows by 19:1, and were regularly spaced at all densities. This behaviour is considered analagous to swarming in other Nematocera. However, all-night human-biting catches show the biting rate to be similar (mean = 8.4, range 2-25 bites per night over ten consecutive nights) to that in N.E. India where VL is endemic. This anthropophagy was maintained during laboratory colonization.