SF Fig. 3.6. Representatives of order Coleoptera, the beetles
Image courtesy of Nicholas Caffarilla, Wikimedia Commons
SF Fig. 3.6. Representatives of order Coleoptera, the beetles
Image courtesy of Nicholas Caffarilla, Wikimedia Commons
British evolutionary biologist and geneticist J.B.S. Haldane quipped that if a god or divine being had created all living organisms on Earth, then that creator must have an “inordinate fondness for beetles.” Beetles (phylum Arthropoda, class Insecta, order Coleoptera) account for a greater number of species than any other single group of living animal. Approximately one out of every four animal species on Earth is a beetle (SF Fig. 3.6).
There is a species of beetle that lives in the intertidal environment, but there are no truly marine beetles. However, it is important to appreciate the diversity of this special group. Hundreds of new species of beetles are still being discovered every year.
Insects are by far the most successful group of organisms on planet Earth, and the only group of invertebrates to have evolved the ability to fly. The class Insecta contains over one million described species, more than double the number of species described from all other phyla combined. Scientists hypothesize that their ability to fly and their close relationships with many flowering plants allowed the huge radiation of insect species. Insects are one of the few taxonomic groups that demonstrate true social behavior, most notably among the bees, ants, and wasps. Insects have an enormous impact on humans. Pollinators like honeybees are necessary for agriculture, and insects like the silk moth and coccineal beetles themselves produce valuable products like silk and dye. Other insects have detrimental impacts. Some carry disease or parasitize humans and others are destructive pests that wreck crops, clothing, books, and buildings. Insects also provide information about environmental health. Aquatic insects are common important indicators of stream health in freshwater systems.