Improved solid adult diet for the olive fruit fly, Dacus oleae

Abstract

Egg production of the olive fruit fly, Dacus oleae (Gmelin) (Diptera: Tephritidae), was higher when insects fed on a liquid diet than on the same diet made solid by enriching it with various amounts of cellite or cellulose. Comparison of a liquid with a solid diet, both composed of water: sucrose: yeast hydrolyzate: chicken egg yolk at ratios 5:4: 1:0.7 and 0:4: 1:0.7 respectively, given to olive fruit flies kept in pairs, showed that egg production was higher on the liquid diet. With grouped insects, however (30 pairs per cage), egg production. expressed per initial female, was higher with the solid diet. The difference was due to the lower mortality that occurred on the solid diet. Dry egg yolk could substitute fresh egg yolk. Among solid diets differing in the concentration of egg yolk, yeast hydrolyzate, and the presence of vitamins and cholesterol, the diet that gave the highest egg production contained 80 parts sucrose, 30 parts yeast hydrolyzate, and 6.6 parts dry egg yolk.