D3283: Marking corn silk flies (Diptera: Ulidiidae) for mark release recapture studies and adult behavioral manipulation

Picture-winged flies, known as corn silk flies (CSF), are a major threat to sweet corn in Florida. The two species of highest economic importance are Euxesta stigmatias and Euxesta eluta. Traditional control methods have failed under high pest pressure, prompting the need for alternative strategies. This research aims to develop a management approach with reduced reliance on insecticides by understanding and manipulating CSF behavior. Mark-release-recapture methods are often used to study insect movement and behavior but require effective marking, and no CSF-specific marking method exists. This study evaluated three marking methods: DayGlo fluorescent pigment on pupae, DayGlo pigment on adults, and food coloring in the adult diet. Results showed that DayGlo marking of adults at 4 grams of dye per liter of adults was a convenient method resulting in high marking proportions without affecting behavior. In a pilot field study, marked adults were released and recaptured in an experimental sweet corn field to initiate the study of their movement. In another field experiment, commercially available baits including NuLure Insect Bait, GF-120 Naturalyte Fruit Fly Bait, and DMB (dimethoxybenzene) were evaluated for their attractiveness to CSF. This project aimed to identify compounds that may manipulate CSF movement away from sweet corn fields to reduce pest pressure and subsequent damage. Corn silk fly adult distribution changed in response to the bait applications.