A computer-controlled video system for real-time recording of insect flight in three dimensions

A computer-controlled video system for real-time recording of insect flight in three dimensions is described. The Fight paths of moths were recorded i n a Fight tunnel using two CCD cameras placed adjacent to each other at ang les of 45 and 135 degrees to the flight tunnel axis and separated by a dist ance of 120 cm. They ware connected to two 2(8)-level gray-scale frame grab bers via two external synchronizers. The two-dimensional coordinates of the flying insect were obtained from the two cameras at 40-ms intervals and tr ansferred to host computer for processing and monitor for real-time display . Due to speed limitation in the image acquisition hardware, construction o f the three-dimensional file was carried off-line. The flying insect wets r endered as a dark spot in a bright background using a homogeneous light sou rce. As the insect enters into the field of view of the two cameras, the li ght distribution changes, and the frame grabber detects only those variatio n in the light distribution which results from a flying insect. The target insect can be as small as 3 pixels and can be tracked in a stereoscopic fie ld of view 60 cm long and 50 cm high. A method was developed that allowed f or scalar scoring of various pheromone sources to assess their attractivene ss using vector flight parameters. This method was applied successfully for optimization of pheromone blend of the grapevine moth, Lobesia botrana.