Drosophila melanogaster’s Developmental Dietary Behavior with Round-up Based Sucrose

Herbicides have been used increasingly in agriculture, but their toxicological effects are still not well understood. Drosophila melanogaster were used to investigate the development of dietary behavior in flies exposed to Round-up, a glyphosate based herbicide. My previous studies analyzed dietary preferences involving Round-up Ready GMO corn and Round-up based sucrose. Previously unexposed flies selected organic sucrose more than sucrose containing a Round-up formulation with pelargonic acid. In this study, female flies reared on treatments with one of two Round-up formulations (containing glyphosate and either pelargonic acid or POEA) or organic medium for one week, were then starved for 15-16 hours, and given 5ul of organic sucrose to consume during the next hour. Simultaneously, an empty vial with 5ul of sucrose was used to measure the evaporation rate. The amount of sucrose consumed per fly is calculated as (sucrose consumed - evaporation rate)/(number of flies). Consumption will be compared across treatments using JMP Statistical Software to determine whether previous exposure to glyphosate-based herbicides affects sucrose consumption. Preliminary results suggest that exposure to increasing Round-up concentrations causes increasing sucrose consumption. Flies consumed more sucrose with higher concentrations of Roundup, which was unexpected since flies often chose to eat less when exposed with the organic and round-up based sucrose simultaneously in a previous study. Flies probably because they are avoiding the medium with Round-up during pre-treatment, which makes them hungrier, resulting in more sucrose consumed during the experimental period