Development of economical protein bait sprays from brewery yeast waste for fruit fly control

• Ministry of Agriculture and Forestry, Tonga

Protein bait sprays based on autolysed yeast cells have proved successful for fruit fly control in Australia and Malaysia. In Australia, one yeast autolysate bait formulation is produced by Burns Philp in Qld and is used for fruit fly suppression or control in areas of low fruit fly populations. In Malaysia, a yeast autolysate (Promar) developed under the first ACIAR fruit fly project (8343* has been used successfully to control large fruit fly populations in carambola plantations. Under field experimental conditions in Fiji, a protein bait spray has shown considerable promise in controlling fruit flies in both commercial and wild stands of guava. For example protein bait sprays applied every 7 days during the rainy season have reduced levels of damage caused by fruit flies to guava from 42% to 6%. This small project will develop a method of treating and autolysing brewery yeast waste from the Royal Brewery in Tonga in order to formulate a protein bait spray for fruit fly control; develop a treatment that has a reasonable shelf-life; test the attractancy of chosen yeast autolysate formulations developed from brewery waste; and establish a model plant in Tonga for brewery yeast waste treatment as a basis for a commercial unit.