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Image Credit: Andrew R. from MI
Image Credit: April from NJ
Image Credit: Bill S. from Manchester, CT
Plain and small in stature, the seemingly simple American Oil Beetle has a few noteworthy tricks up its sleeve.
American Oil Beetles are a type of Blister beetle. When threatened or squeezed under pressure, they emit a chemical called cantharidin that creates blisters and irritates human skin. These wounds will heal, but they are painful. This chemical defense can ward off predators and give the beetle time to escape.
American Oil Beetles have a soft, yet stout abdomen with a shell covering that looks like a series of overlapping plates. The insect can appear as a dull black or, in some cases, a shiny black or dark blue. The surface texture is slightly bumpy, not slick and smooth. Antennae are visible on the head.
These particular beetles do not fly and are slow movers. Adults can be found gingerly walking around plants they eat, such as buttercups, and in grass. They are active all year, but more so in the spring, when they are more likely to be seen. The larvae are somewhat devious. One will sit on flowers, waiting for a bee to land. It will latch onto the bee for a free ride back to the hive. Once there, the beetle larva feeds on the same food as the bee larvae. It will pupate safely inside and emerge in the spring.
Scientific Name: Meloe americanus
Size (Adult; Length): 7mm to 17mm (0.27in to 0.66in)
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Antennae: Beetles have a pair of antennae on the head used as sensors.
Head: The head is home to the insect's eyes, antennae, and mandibles (jaws).
Thorax: Holds the three pairs of legs as well as vital internal organs.
Elytron: One of two wing cases on a Beetle that protects its wings (plural: elytra).
Wings: Appendages used for flying and kept under the elytra until needed.
Abdomen: Houses organs related to circulation, reproduction, and excretion.
Legs: Beetles have three pairs of legs located at the thorax, numbering six legs in all.