Non-stinging insects seldom get much respect, but some get even less than most. Over-sensitized perhaps by repressed memories of potty training, the average person tends to recoil in disgust from the topic of dung beetles. After all, what creature would dabble in excrement? The dung beetle might well answer, "Well, it's a living".
Fashioning the dung of animals into a ball, they roll it away from the source and eventually bury it as food for their young. In most places, dung is a limited vital resource, and the best strategy for preventing other dung beetles from high-jacking their prize is to move away from the attractive source in the most efficient way possible--a straight line. But how does an insect with limited view of its surroundings assure that it is moving in a straight line? In a first, researchers now have shown that the beetles use patterns of polarized light from the moon.
Enjoy our beautiful desert moon, but know that those busy little denizens of the night view it quite differently—as an all important compass.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.
Dacke, M., D. Nilsson, C. H. Scholtz, M. Byrne, and E. J. Warrant. 2003. Insect orientation to polarized moonlight. Nature, 424:33.