Effectiveness of foliar protein bait sprays in controllingBactrocera invadens(Diptera: Tephritidae) on sweet oranges

Abstract

Introduction. Damage caused by tephritid fruit flies has been identified as a major limiting factor to citrus production in Nigeria. Presently, no control measure is applied by the majorityofthefarmers.Thisstudythereforeseekstoevaluatetheefficacyoflocally-madeprotein bait sprays and the differences in the susceptibility of sweet orange varieties in reducing fruit fly damage. Materials and methods. In 2006 and 2007, one, two and three spot applications of locally-made protein bait mixed with chlorpyrifos insecticide were administered to Agege, ParsonBrownandValenciaLatesweetoranges.Treatmentswerearrangedinarandomizedcom- plete block design. Efficacy of the bait sprays in reducing fruit attack was assessed by randomly sampling 10 ripe or ripening fruits per stand as well as dropped fruits. Results and discussion. The bait sprays significantly (p < 0.05) reduced damage of sweet orange by lowering the infes- tation level of Bactrocerainvadens Drew Tsurata & White, and consequently reducing the num- ber of dropped fruits. Application of three spots of bait was most effective in reducing damage due to B. invadens on sweet orange varieties. The infestation level of B. invadens and the num- ber of dropped fruits of the variety Agege were significantly (p < 0.05) higher than those of the varieties Parson Brown and Valencia Late. Conclusion. Our study shows that three spot appli- cations were most efficacious in reducing fruit damage, and that the Valencia Late variety was the least damaged, followed by Parson Brown. Nigeria / Citrus sinensis / fruits / Tephritidae / insect control / damage / fruit drop / chemical control / application methods / application rates