Of all the groups of organisms in the animal kingdom, insects are among the most interesting. They are among the most numerous, most widely distributed, and most diverse of all animal groups. In fact, according to Evans (p. 2) insects are the most numerous of all terrestrial animals, and represent a biomass on Earth almost 30 times greater than that of human beings. Furthermore, with over 1,000,000 species, they are the "most abundant of all living things in terms of numbers of kinds" (p. 2). In other words, on an evolutionary scale, insects are among the most successful organisms this planet has ever seen.
When considering the extraordinary abundance of insects, their almost universal distribution, and their relatively small size, it is no surprise that they play an integral role in many food webs, and are an extremely important food source for many different animals (p. 307). Nevertheless, insects have been extremely successful in avoiding predation, and have adapted many different strategies that allow them to do so. Evans (p. 309) identifies two different categories of defenses employed by insects to defend themselves from predation. First are the primary or passive defenses. These strategies are passive in the sense that they are intended to help the insect avoid predation regardless of the presence of a specific threat. However, many insects also have a back-up plan, referred to as secondary or active defenses. These strategies are typically behavioral, and are intended to increase an insect's chances of escaping predation, once they are under attack. While there are countless strategies that the insects employ, the remainder of this paper will focus on those defensive adaptations that relate to coloration.
One of the most common primary defense strategies employed by insects is referred to as crypsis, or cryptic coloration. According to Edmunds (p. 3) "crypsis is the color resemblance of an animal to its background so that predators (or other animals) have difficulty in distinguishing it.
