Starvation Induction and Assessment of Sugar-Influence on the Foraging Behavior in Male Drosophila Flies

To begin, collect adult male Drosophila flies within 12 hours from emerging. Place them on standard fly media for 48 hours at 25 degrees Celsius. Starve the flies of food, but retain their access to water.

To calculate the food starvation of two day old flies, place 15 to 20 flies in a vial with soaked tissue paper at the bottom. Transfer the starved flies individually into small tubes. Place the tubes near the illuminated arena, surrounded by a white polyvinyl chloride pipe.

Use the camera software to focus on the arena. Place about two microliters of sugar solution in the arena center. Now, slowly invert the micro centrifuge tube with a single fly over the sugar drop.

Film the 2D position of the arena with an overhead camera. Finally, analyze the trajectory of each fly to determine its search behavior. Sugar intake in starved flies led to a local search with a meandering path and loops.

The unfed flies, however, did not initiate a search, but instead, escaped the arena. The parameters of search, that is path length, stay time, meander, and number of returns were significantly lower in the unfed flies.