Insects are arthropods -- animals whose physical characteristics include exoskeletons and multiple legs. Class Insecta all have six legs, three body sections, one pair of antennae, compound eyes and exoskeletons composed primarily of chitin. They account for approximately 1 million of the 1.8 million known animal species on Earth. Quite a few interesting ones are indigenous to Tennessee.
Counting insect species in an area can be tough: they're small, often on the move and may have dramatically different-looking life stages. Tennessee has at least 200 resident insect species. Some were introduced from other regions, others -- like almost all butterflies -- are migratory and can't be considered indigenous to any single place. Bugs don't respect state boundaries, and indigenous Tennessee insects are native not only to Tennessee, but to entire geographic regions, such as the Appalachian Mountains, North America east of the Rockies, or the temperate U.S. south. Trying to list every single indigenous Tennessee insect would be a very long and complicated endeavor, but the state has a few particularly odd natives who are especially worthy of note.
Beetles account for some of Tennessee's oddest fauna. Meloe americanus is commonly called the oil beetle or American blister beetle. She looks sort of like a giant, matte-black space ant. She scored her common names by leaking poisonous, oily bug blood from all her joints when she's disturbed, which causes swelling, burn-like wounds in unwary humans who touch her. Her young look like tiny maggots with clawed feet. They attach to bees, who accidentally deposit them in their own nursery cells, where they devour the larvae's food and sometimes the larvae themselves.
The Acharia stimulea moth is nothing to write home about. With his light brown background and slightly darker brown stripes, he looks pretty much like any other boring brown moth -- but anyone who meets one of his children is unlikely to ever forget the experience. The saddleback caterpillar is memorable not only for his long front and back horns and bright green "saddle," but for his several hundred urticating spines -- hollow spikes filled with hemolytic poison. Spines can break off and stick to clothing and surfaces and may even become airborne. A surprise encounter with a young A. stimulea will hurt more than just your feelings -- watch for the warning coloration and steer clear.
Tennessee has vast pine forests and vast numbers of pine pests. Pine eaters include at least two species of native beetle, two weevils, a moth and the redheaded pine sawfly. Though she's called a fly and her young look like caterpillars, Neodiprion lecontei is actually a hymenopteran -- a close relative of bees, ants and wasps. Adults look like redheaded black wasps. Larvae are smooth with red heads and green to black dark spots on a white background. They can completely infest conifers until a tree looks like all its needles have been replaced by caterpillars. These native insects don't cause significant damage in healthy forests, but can wipe out numerous trees when forests are already weakened by other factors.
- BugGuide.net: Species Neodiprion lecontei - Red-Headed Pine Sawfly
- Auburn University College of Agriculture: The Redheaded Pine Sawfly - A Guide to Recognition and Habits in Alabama
- University of Florida Department of Entomology and Nematology: Common Name - Saddleback Caterpillar
- InsectIdentification.org: Saddleback Cateripillar - (Acharia stimulea)
- Tennessee Department of Agriculture: Common Insect Pests of Tennessee Forests
- InsectIdentification.org: American Oil Beetle - (Meloe americanus)
Angela Libal began writing professionally in 2005. She has published several books, specializing in zoology and animal husbandry. Libal holds a degree in behavioral science: animal science from Moorpark College, a Bachelor of Arts from Sarah Lawrence College and is a graduate student in cryptozoology.