The insects are 2-3 mm long and are found throughout the tropics and temperate the world. The sandfly larvas require organic matter, heat and humidity for development and so are commonly found in household rubbish, the bark of old trees, burrows of old trees and in the cracks in house walls. Sandflies usually feed at night. Only about 30/500 species of Phlebotomine sandflies are known to transmit leishmania parasites. These include P. argentipes in Indian, P. martini and P. orientalis in Africa and the Mediterranean basin, and P. chinensis and P. alexandri in China. In the New World Lutzomyia longipalpis is the only known vector of L. d. chagasi.