Good Beetle: Fiery Searcher Caterpillar Hunter

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One of the most striking beetles that you'll ever find in Ohio is the fittingly named Fiery Searcher Caterpillar Hunter (Calosoma scrutator).  But be careful.  This meat-eating beetle is accurately described as beauty with a bite. 


Their beauty is displayed with deeply grooved metallic green elytra edged in lustrous reddish-orange.  The elytra are hardened front wings that protect the abdomen and membranous hind wings.  All beetles share this general body plan as described in name Coleoptera:  coleo = sheath; ptera = wing.


Fiery Searcher Caterpillar Hunter


The eye-candy continues with the dark blue prothoracic shield which is also edged in a radiant ring of copper-orange.  This flame-like motif is responsible for the "fiery" in the common name.  Flipping the beetle over (carefully!) reveals a carnival glass-like mix of green and reddish-copper markings that play off the colors of the long legs best described as purplish-dark blue fading into electric-violet. 


Fiery Searcher Caterpillar Hunter


The bite of this predacious beetle comes from their powerful, sickle-shaped mandibles.  Fiery searchers hunt down and feast on free-range caterpillar meat as well as any other soft-bodied insect they can clamp their mandibles on; thus the "caterpillar hunter" in their common name.


Fiery Searcher Caterpillar Hunter


Fiery searcher caterpillar hunters live for 2 to 3 years spending the winter beneath bark or in the soil.  They are one of the largest "ground beetles" (family Carabidae) found in Ohio measuring around 1 1/4" in length.  These meat-eaters are one of our more significant insect predators with the capability of having a substantial impact on the population densities of general defoliators.


The beetles are commonly found feeding on gypsy moth (Lymantria dispar) caterpillars as well as pupae.  Once adult moths emerge, the beetles typically go on a crawl-about in search of food which may cause them to show up in unexpected places.


Gypsy Moth


Their large size and obvious hunting equipment which includes long legs, big eyes (The better to see you with, my dear!), as well as obvious mandibles (The better to eat you with, my dear!) makes the fiery searcher a perfect model for teaching about insect predators.  Of course, you should use pictures, not live specimens because they bite.  They're wolves after all.


Fiery Searcher Caterpillar Hunter