Hessian Fly (Diptera: Cecidomyiidae) Attraction to Different Wavelengths and Intensities of Light-Emitting Diodes in the Laboratory.

Monitoring of Hessian fly, Mayetiola destructor (Say) (Diptera: Cecidomyiidae), populations is important for targeted management methods. Also, effectiveness of monitoring efforts is critical to surveillance efforts in regions of the world without this pest. Current Hessian fly monitoring traps rely purely on a single attractant, the female sex pheromone, which is ineffective for monitoring females in the population. Our objective was to examine another attractant targeting vision of both males and females. To do this, we evaluated emitted light of various wavelengths and intensities produced by light-emitting diodes (LEDs). Hessian flies were released in the center of a four-leaf clover-shaped arena, which contained an LED within each collection cup at the apex of each of the four cloverleaves. Initially, we examined a range of colors, including red, amber, green, and blue, with wavelengths of 624, 590, 527, and 472 nm, respectively. Both sexes of Hessian fly preferred green LEDs; therefore, we examined specific wavelengths within the green spectrum (502, 525, and 565 nm), and varied light intensities (4, 8, 12, and 16 W/m2). Specifically, females preferred wavelengths in the lower region of the green spectrum (502 and 525 nm), and both sexes preferred high intensity light (16 W/m2). This is the first report of Hessian fly attraction to select emitted wavelengths and intensities from LEDs under controlled conditions. Leveraging these results into new trap designs will add a second sensory modality to the existing trap; however, future studies are needed to assess attraction to LED traps under field conditions.