Studies on the ecology and biology of a cocoa pollinator,Forcipomyia squamipennisI. & M. (Diptera, Ceratopogonidae), in Ghana

Abstract

AbstractFrom field observations and laboratory rearings, the biology ofForcipomyia squamipennisI. & M. in cocoa plantations in Ghana was established as follows. Adult midges are found between buttresses of large shade trees, in crevices of decayed old logs, in hollow tree stumps and cocoa husk heaps. Swarming takes place at any time during the day in or around the resting place, while dispersal occurs in the early morning and in the late afternoon, the normal flight range being 5–6 m. The largest populations occur in the rainy season. Eggs are laid on moist decomposing wood, cocoa husks and other plant debris in batches of 40–90; the larvae hatch in 2–3 days and pupate after four moults, when about 12 days old; the pupal stage lasts 2–3 days. Adult females require liquid plant food for survival and oviposition, although the maturation of ova is independent of adult food intake or mating; unfertilised eggs do not develop. The maximum adult life span for both sexes is eight days in captivity.F. squamipennisundergoes at least 12 generations a year. Due to its abundance and continuous breeding in cocoa plantations,F. squamipennisis probably the most important Ceratopogonid cocoa pollinator in Ghana. Both sexes are efficient pollinators, but four times more males than females visit cocoa flowers.