Chapter 62 - Crypsis

Abstract

This chapter discusses crypsis or camouflage, which insects uses for survival from predators that hunt them by sight. An insect that is perfectly camouflaged is perhaps one of the most striking exhibitions of the power of evolution by natural selection to mold and adapt organisms to fit their environment and to maximize survival and reproductive success. The apparent perfection of crypsis is emphasized in many insects by a similarity of, and matching of, the color pattern of the wings, body, and appendages to the background on which they normally rest. The color pattern of these different body parts and structures involves different genetic and developmental pathways, and yet evolution has led to a corresponding perfection of matching, albeit using entirely different mechanisms of pattern formation. Color matching in crypsis is almost always only one component of the strategy for survival; both habitat choice and, frequently, the adoption of very specific patterns of behavior and activity are required for effective crypsis. The analysis of crypsis and the evolution of a color pattern from the perspective of changes in camouflage involved industrial melanism in the salt and pepper moth, Biston betularia. The fundamental components of this classic example of the evolution of an adaptive trait also apply to numerous other species of moth and other insects that have evolved melanism as a response to environments influenced by air pollution.