Observations on the mango fruit fly Ceratitis cosyra in the Coast Province, Kenya.
With the expansion of the mango industry in the Coast Province, Kenya, the importance of the tephritid Pardalaspis cosyra (Wlk.) (Ceratitis cosyra) has increased. High-quality commercial varieties are more heavily infested than poorer ones, and fruits picked from trees are less infested than ones picked from the ground. In a survey in 1974-75, P. cosyra was the main pest of mango; it was also associated with guava and sour orange. The biology (including oviposition behaviour) of the tephritid is described from observations in the laboratory and field. After hatching, the larvae fed on the pulp of the fruit around the oviposition cavity just below the skin, which became marked with a yellowish patch. A few days later they burrowed further into the pulp, and when fully grown they were found throughout the flesh. The number of larvae in infested fruit averaged 50. Fully fed larvae readily burrowed into moist soil, and pupation took place within 24 h of leaving the fruit. At 28.8-32.7 deg C, the pupal stage lasted 9-12 days. Adults of both sexes lived for up to 41 days, but oviposition took place only in the first 2 weeks. The first egg-mass was laid 5 days after emergence of the female. Of 377 fruits collected, 26 contained larvae of P. cosyra; and at the peak of harvest in January 25% of fallen fruits were infested. It is suggested that all fallen fruits should be destroyed and that poisoned baits can be used to attract and kill the flies before they lay their eggs.