Published online by Cambridge University Press: 15 October 2004
Introduction. Damage of citrus fruits by the Mediterranean fruit fly Ceratitis capitata Weid. results in economic losses in Nigeria. The majority of the citrus producers are small-holders who are yet to adopt standard citrus production practices. A trial was therefore established in a savannah zone of Nigeria with a Southern Guinea agroecology to evaluate simple fruit fly control practices. Materials and methods. The efficacy of combining cultural practices such as removal of dropped fruits, changes of harvest period, and three applications of dimethoate/cypermethrine mixture in controlling fruit fly damage was tested on sweet orange Citrus sinensis (L.) Osbeck var. Valencia Late in 2000 and 2001. Results. Fruits attacked by C. capitata increased with fruit maturity and were positively correlated with the number of dropped fruits. Insecticide applications and removal of dropped fruits significantly reduced the number of fruits attacked by the fruit flies. Similarly, early harvesting at 50% fruit ripening significantly (P < 0.05) reduced the number of fruits attacked by the fruit flies when compared with the late harvesting at 90% ripening. The interactive effects of insecticide applications and the period of harvest significantly (P < 0.05) reduced attacks on fruits. Discussions. Judicious use of insecticides, periods of harvest and removal of fallen fruits reduce fruit fly damage. Late harvest and non-removal of fallen fruits constitute fruit fly reservoirs for the re-infestation of other clean fruits. Since the tested control methods were simple, they can be adopted by small-holders for the control of fruit flies.