The study reported examined mechanisms of pollen transfer within the genus Lagenaria, including insect vectors in the natural and cropped field environment. The major flower visitors to Lagenaria were observed for 10 months, from June 2001 to April 2002 at five sites, namely the Botanic Garden of the National Museums of Kenya, three farmers' crop fields in Dungicha village in Kilifi District, Katitika and Wayowani villages in Kitui District and the home garden of one of the authors, in Westlands, Nairobi, Kenya. Twenty-two species of insects represented in four orders belonging to 10 families were found to be the major visitors of L. siceraria flowers. From the foraging patterns of the flower visitors, visiting frequencies and development of fruits, four groups of flower visitors comprising hawkmoths (Hippotion celerio, Agrius convolvuli), moths A–D (Noctuidae spp.), skipper butterfly (Gorgyra johnstoni) and honeybee (Apis mellifera) were considered active flower visitors. Hawkmoths were suspected to be the major pollinators of this plant in the locations surveyed.