Waste Brewer’s Yeast as an Alternative Source of Protein for Use as a Bait in the Management of Tephritid Fruit Flies

Abstract

Yeast, and products of yeast, are composed of proteins, carbohydrates and minerals that fruit flies can utilize for development. They are being considered widely as alternative sources of protein for baits used for fruit fly suppression. In this chapter, we describe how we used techniques developed in Australia to developed fruit fly protein baits from waste brewer’s yeast (WBY) from breweries in Kenya, Tanzania and Uganda. In attraction and feeding response studies, protein originating from waste yeasts compared favourably with commercially available protein baits used for fruit fly suppression. In field evaluation trials, the total number of oriental fruit fly, Bactrocera dorsalis, captured in Kenyan (112.1 flies/trap/day [FTD]) and Ugandan (109.8 FTD) WBY was superior to the standard NuLure (56.8 FTD) although Torula yeast gave the highest catch of 132.4 FTD. In field suppression trials, mango fruit infestation by B. dorsalis in treatments receiving protein bait originating from Kenyan WBY in combination with other management methods incurred 6.7–20.0 % fruit damage compared to 65.6 % fruit damage in the untreated control. The results suggest that locally developed protein baits made from WBY offers a suitable alternative to expensive imported food baits for the management of fruit flies in Africa. On the basis of these results, a local commercial protein bait production plant using WBY is being established in Kenya inspired by a similar facility in Mauritius.