ORIENTATION OFCALOSOMA SYCOPHANTAL. (COLEOPTERA: CARABIDAE) IN FORESTS: INSIGHTS FROM VISUAL RESPONSES TO OBJECTS

Abstract

AbstractVisual responses of adults ofCalosoma sycophantaL., which are predators of the gypsy moth,Lymantria disparL. (Lepidoptera: Lymantriidae), were investigated in laboratory arenas. Beetles moved toward dark cylinders significantly faster than to light ones when the background was white, but no differently when the background was black. Thus,C.sycophantaappears to respond most readily to dark objects, and this response is only slightly modified by contrast with the background. Beetles move toward large-diameter black cylinders more readily than toward small-diameter ones, but object height and shape do not appear to be important characteristics. The visual responses ofC.sycophantawould tend to orient adults toward the base of trees in a forest. Because beetles prey on gypsy moth larvae in trees, this orientation serves to position them where they can most readily find hosts, or perhaps to guide them to objects under which to hide.