Objects of different colors, shapes and sizes made of bamboo frames and clothes were paired and alternatively placed in a circle of 7.5m radius in an open area. Eight subjects, four of the same color or shape were placed the same distance between each other in the circle. Around 50 caged beetles were released in the center of the circle at the rate of around 1 beetle per 2 minutes. The flight path of individual beetles visually tracked and some of them were videotaped. For each beetle that flies, the following were noted: (1) time, (2) point where the beetle reached the edge of the 7.5-m circle, (3) whether the beetle was above or below the tops of the silhouettes when it reached the edge of the 7.5-m circle, (4) where the beetle landed; and (5) what flight track the beetle took between the release point and the point were it either landed or left the arena. Weather conditions such as temperature, humidity, solar radiation, wind speed, wind direction during all observation periods were recorded.
Azimuth of the sun and the point of release as well as wind affected initiation and paths of flight of the beetle. The flight paths of the beetle showed that the beetle was able to perceive objects when flying close to the object. Among those beetles that flew, almost half landed on the tested subjects. More beetles landed on black than they landed on yellow or green or white. When black colored cloths of different shapes were placed, more beetles were landed on the taller cylinder than they landed on cylinder of 1/2 high but twice as much as the radius of the cylinder or cones of the same height and bottom radius with the taller cylinder.
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA