The buzz on attraction of blue vane traps to native bees

Worldwide, concerns about declines in populations of native bees have generated interest in bee census studies. For continued assessment of native bee status there is urgent need for an effective sampling technique. At Oregon State University, during a monitoring study on an unrelated insect, we serendipitously discovered that a particular blue vane trap served as a 'supernormal stimulus' for native bees. In subsequent studies the traps captured over 70 native bee species in 23 genera in 4 families. The objective of this study was to determine the basis of the attraction of the traps to native bees. We compared bee captures in blue traps with captures in a diversity of colored and fluorescent traps. Transmission, reflection, absorption, and UV-induced fluorescence of vanes were measured using various light sources including AM1.5G solar simulator and spectrometers. Data analysis indicated that sunlight-induced fluorescence rather than blue maybe the key factor that serves as the 'supernormal stimulus'. Potential applications of the blue fluorescent vanes for manipulation of bee behavior will be presented.