The mating and swarming behavior of A. culicifacies was investigated during Dec. 1975 at a cattle shed near Sattoki, Lahore District, Punjab, Pakistan. On an average, swarming commenced 20.9 min before sunset (light intensity 1414.4 lx) and ended 21.0 min after sunset (5.4 lx) with pairing restricted to the period from 6.1 min before (467.2 lx) to 15.8 min after sunset (26.9 lx). Swarms were principally composed of males, with females entering only for mating. An average copulation lasted 27.2 s and was completed in flight. Most females (71.8%) collected while mating had taken a partial blood meal either the previous evening or on the same evening as mating. All females in the swarms were nulliparous and 82.6% had ovaries developed to at least Christophers'' stage IIa.