Effect of visible light sticks for collecting of adult caddisflies (Trichoptera): A preliminary field study

Local residents along the Uji River, Kyoto, Japan, may be exposed to seasonal invasions of adult caddisflies. Ultraviolet (UV)-blocking materials are believed to be an effective pest management tool because adult caddisflies are often attracted to light sources that emit large amounts of UV light. To clarify the effect of the visible spectrum, we collected adult caddisflies using blue, green, and yellow light sticks that did not emit UV light. Traps were operated from 18:30 (sunset: 18:22) on September 2, 2016 to 06:00 (sunrise, 05:31) on September 3, 2016. We collected 382 adults representing eight species of caddisflies. Green light sticks attracted the most numerous individuals (189 adults, seven species), followed by blue (134 adults, seven species), then yellow (59 adults, five species). Paduniella tanidai Nishimoto was the dominant species (331 adults). These results suggest that adult caddisflies are attracted not only to the UV spectrum but also the visible spectrum.