Effects of varying the dietary nitrogen to carbohydrate ratio upon the biological performance of adult Dacus oleae (Diptera Tephritidae)

Abstract

By varying the dietary proportions of nitrogen to carbohydrate in a chemically defined diet, it was found that the olive fruit adult fly cannot utilize amino nitrogen as an energy source, while the most critical ingredient for prolonged survival was the carbohydrate part of the diet. Increase of the nitrogen contents above 1.6 %, up to 6.4 %, shortened adult life span by 50 %. The best reproduction rate was scored under a N/C ratio of 1.6/40, while higher nitrogen contents reduced egg deposition. Fertility was adversely affected by low sucrose concentrations as well as by total absence of amino nitrogen, while higher nitrogen concentrations proved also detrimental to egg hatchability.