Phototactic Responses of Drosophila melanogaster to UVA, UVB, White Light, and Dark Environments

Abstract

 Ultraviolet A (UVA) radiation comprises a large portion of the solar radiation found on Earth. UVA exposure has been shown to induce both harmful and beneficial biological effects on insects. The objective of this study was to observe if Drosophila melanogaster, a relative of the North American common household pest, are attracted to or repelled by UV light when alternative light conditions are present. We performed 3 experiments that gave the flies a choice between [1] UVA or UVB light areas,  [2] UVA light or a dark space, [3] a white light only area or a UVA in combination with white light space. In all three cases, we found significantly more flies in the UVA exposed areas (≥ 80%). This suggests that fruit flies exhibit positive phototaxis toward UVA light. Our data provide insight to the behavioral preferences of fruit flies, and show potential for a UVA component to be involved in a successful pest trapping device.  Future research can be conducted to determine how to combine a UVA light source with current trap designs to increase its effectiveness.