Brief Summary Eleodes
Eleodes is not only the largest genus in terms of physical size in the Tenebrionidae, the darkling beetles, but it is also the largest in terms of the number of species. There are over 230 described species of Eleodes, about 132 of which are found exclusively in the Western portion of the US in arid and semiarid environments (Bernett, 2008). The larva of this genus is often referred to as a ‘false wireworm’ because they look similar to the larva of the family Elateridae, the true ‘wireworms’ (Bernett, 2008). In semiarid environments they are of economic importance because they feed underground on many plants. Although the larva can help irrigate the soil (Arnett, 2002) they can also be harmful to some plants that are commercially grown, such as wheat (Bernett, 2008). Adult Eleodes are especially noted for the odd posture they take while avoiding potential dangers: they point their abdomens in the air at about a 45° angle as they run away, almost as though standing on their heads. Running in this fashion may not be quite as speedy, but it does enable the beetle to utilize another defense. This genus is noted for the noxious quinone spray that some species produce when disturbed (Triplehorn, 2005). The abdomen-pointing behavior enables the Eleodes beetle to spray the chemical at potential predators. However, some mice have evolved a strategy to avoid this defense. By grabbing the beetle and sticking it into the dirt abdomen first, the mouse is able to begin eating the palatable portion of the beetle while the quinone is discharged without discomfort (O’Toole, 1986). Skunks have also developed a method for preying upon Eleodes: after capturing a beetle they roll it on the ground releasing the quinone onto the substrate and thus making the beetle edible. (Slodobochikoff, 1978). In addition to mammalian predators, fifty-one species of birds have also been recorded to feed on a particular species, E. tricostata. It is interesting to note that although this species of Eleodes does preform the abdomen-pointing behavior, it does not actually produce chemical defenses (McAtee, 1932).
- Arnett, R.H., Thomas M.C., Skelley P.E., Frank J.H. 2002. American Beetles, Polyphaga: Scarabide1a Through Curculionidae. New York, NY: CRC Press LLC.
- Bernett, A. 2008. The genus Eleodes Eschscholtz (Coleoptera: Tenebrionidae) of eastern Colorado. Journal of the Kansas Entomology Society.81, 377-391.
- McAtee, W.L. 1932. Effectiveness in nature of the so-called protective adaptions in the animal kingdom, chiefly as illustrated by the food habits of Nearctic birds. Smithsonian Miscellaneous Collections. 85, 1-201.
- O’Toole C. ed. 1986. The Encyclopedia of Insects. New York, NY: Facts on File, Inc.
- Slobodchikoff C.N. 1978. Experimental studies of Tenebrionid beetle predation by skunks. Behaviour. 66, 313-322
- Triplehorn, C.A., Johnson N.F. 2005. Borror and Delong’s Introduction to the Study of Insects: 7th edition. Belmont, CA: Thomas Learning.
The pinacate beetle, also known as the stink beetle, is a genus of darkling beetle endemic to the Sonoran Desert and adjacent regions of the U.S. Southwest and Mexico, usually the species Eleodes obscurus. The name is also loosely applied to a number of closely related species of Eleodes, of Western Mexico and the Western United States (including but not limited to the Great Basin), which, aside from the wooly darkling beetle, are not easily distinguished from each other. The name pinacate is Mexican Spanish, derived from the Nahuatl (Aztec) name for the insect, pinacatl, which translates as "black beetle".
The pinacate beetle is noted for its defensive tactic of standing on its head and squirting a noxious spray. This has earned it the additional names of clown bug and stink bug, names also applied to other unrelated insects.
References in popular culture
The pinacate beetle can be seen in the Sergio Leone classic western movie For a Few Dollars More, starring Clint Eastwood, Lee Van Cleef, and Gian Maria Volontè. In the scene just before the climactic final shootout between Colonel Douglas Mortimer (Van Cleef) and Indio (Volantè), Indio, while seated at a wooden table, being held at gunpoint by one of his gang members, smashes a pinacate beetle that scampers across the table in front of him.
In another Clint Eastwood movie, The Outlaw Josey Wales, Eastwood's character (Josey Wales) has a habit of spitting tobacco juice on several objects throughout the movie, including a hound dog's head, a dead assassin's forehead, and a pinacate beetle.
Off-road motorcycle riders, when discussing a particular machine, may refer to "stinkbug" handling when the machine has a front-low, rear-high feel to it, alluding to the pinacate beetle's defensive posture.
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