Local production of protein bait for fruit fly monitoring and control.
Protein baits are widely used in fruit fly management, both in traps for monitoring and as spot sprays for control. A range of studies have used McPhail traps to assess the relative performance of commercial protein hydrolysate baits and various home-made autolysates of brewery waste yeast to develop home-made alternatives to imported hydrolysate bait. In Mauritius, locally made yeast autolysate, produced by a combination of heat autolysis and papain enzyme promoted proteolysis, was tested in field experiments using McPhail traps in mango orchards and in wild growing mango trees at 3 locations from December 1998 to January 1999. The most abundant fly species were Bactrocera zonata, Ceratitis rosa and B. cucurbitae. The locally-made bait was generally as effective when used in McPhail traps as commercially obtained protein hydrolysate bait. However, the locally-made bait did not effectively trap B. cucurbitae. Fruit fly catches were greater when protein autolysate was prepared with higher concentrations of papain (2.0 or 4.0 g/litre). In similar experiments in Kenya, conducted in mango orchards in February 2000, certain locally produced autolysate bait formulations out-performed commercial hydrolysate in attracting Ceratitis cosyra.