Beetles are in the order Coleoptera and represent the greatest diversity of any group of animals. There are more than 340,000 described species worldwide, including nearly 30,000 species in North America alone making it the largest order of insects. Beetles are distinguished from other insect groups by a pair of forewings that are usually hard and rigid, are never used for flight, and serve as a protective covering for the delicate flight wings and the upper surface of the abdomen.
As you might expect with so many species beetles come in all shapes and sizes and are found in nearly all habitats. Beetles are important as they provide a whole variety of ecosystem services. They are predators of crop pests, dung beetles and carrion beetles help keep ecosystems clean and many beetles are important pollinators especially in the tropics.
Most beetle species undergo complete metamorphosis, which usually has four main stages: Egg, larvae, pupa and adult. The larvae are commonly called grubs and some species enclose the pupa in a cocoon constructed by the larva.
Threats and Conservation Status
Because of the incredible diversity, we do not know much about the status of many of our beetle species. There are 17 species listed as threatened or endangered under the US Endangered Species Act but many more are likely in decline. Of the beetles with IUCN-documented population trends, over 60% are declining.
As with other species of insects, beetles are declining due to habitat loss and fragmentation, pesticides, climate change and potentially light pollution and disease. You can help beetles by providing a variety of native plants in the landscape and not using pesticides. You can also help by not buying and releasing lady beetles (sometimes called ladybugs). This practice harms native lady beetles at collection sites, may harm local populations at release sites and is not effective at helping control local pest species.