Beetles belong to the order of species called coleoptera. The vast amount of species in this order"about 400,000--is greater than that of any other order, and makes up about twenty-five percent of all known life forms. In the insect world, forty percent are a species of beetle, and new species are discovered often. Scientists estimate that there are about one million species of beetle, including
. those that have yet to be discovered.Beetles may be found all over the world, excepting the polar areas. Their feeding habits vary from wood, fungi and other invertebrates. Some break down forest litter like animal and plant debris, and other species are considered farming pests. Still other species control other agricultural pests, such as ladybugs.Beetles generally have a hard exo-skeleton, which serve as armor to protect their other anatomical structures. While the physiology of the majority of beetle species is shared, they do differ in the presence of specific organs and number of appendages. Adult beetles usually have two pairs of wings. Beetles also share common anatomical features with many other insects.In mating, beetles have very specialized codes of behavior that involve pheromones and aggression among males, among other intricate communication techniques. Among males and females there is often an exaggerated sexual dimorphism, meaning that females and males of the same species have extremely different physical appearances. Beetles also go through metamorphosis after birth, during which considerable and sudden changes in body structure occur.Common species seen in North America include the ladybug, carpet beetle, powder post beetle, merchant grain beetle, the boll weevil and Japanese beetle.Bugguide.net contains helpful information, including several thumbnails of various beetle species, to use when identifying beetles at http://bugguide.net/node/view/60.An introductory guide for studying and identifying beetles by anatomical features and appearance may be found at http://entnemdept.ufl.edu/choate/beetles.pdf.More reference links: http://bugguide.net/node/view/60 http://entnemdept.ufl.edu/choate/beetles.pdf
