Family Pyrochroidae - Fire-Colored Beetles

PYROCHROIDAE: from the Greek "pyros" (a fire) + "chroma" (a color) - origin of the common name and a reference to the bright red or orangish color in some species

nearctica.com lists 56 species in 8 genera in North America

adult 6-19 mm; larva to 25 mm

Adult: medium-sized, often black with some red ("fire color"). Elytra wider at rear. Elytra wider than pronotum. Head has a distinct neck. Antennae of males often pectinate to flabellate.

Larva: long (to 25 mm or 1") yellow body, reddish-brown at both ends; abdomen seemingly 9-segmented, the first 7 segments lobate and wider than long, the 8th segment longer than wide, the 9th segment bearing two urogomphi (claw-like "spines"); 2 long hairs project laterally from each abdominal segment; body surface covered with small bumps or "warts".

Often found around decaying wood.

Although larvae are sometimes cannibalistic at high population densities, they are not normally predaceous (Young, 1975). J.M. Campbell in the Checklist of Beetles of Canada and Alaska; Pyrochroidae states: "The feeding habits and biology of pyrochroids were summarized by Young (1975). Larvae live in dead wood and are apparently fungivorous rather than predaceous or xylophagous as reported by earlier authors." It seems that older sources may have listed the larvae as carnivorous/predaceous (i.e. Arnett 1968 when citing literature from 1914-1951). -- from comments by Charlene Wood here

Adults are active at night, and may be attracted to lights. Some species may be attracted to fermenting baits.

Male pyrochroid beetles seek out blister beetles, climb onto them and lick off the cantharidin the blister beetles exude. Not only have these beetles developed a resistance to the cantharidin, they use the blistering agent to impress a female of their own species who then mates with them, whereupon most of the cantharidin is transfered to the female in the form of a sperm packet. The eggs the female subsequently lays are coated with cantharidin to protect them from being eaten before they hatch.

… Jim McClarin, 26 March, 2006 - 4:00pm

larvae of Cucujidae have shorter terminal appendages and their 8th abdominal segment is not longer than wide

Young, Daniel K. 1975. A revision of the family Pyrochroidae (Coleoptera: Heteromera) for North America based on the larvae, pupae, and adults. American Entomological Institute. Vol. 11. 39 pp.

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images of adults and larva (William Godwin, Texas A&M U.)

live larvae image of the palearctic species Pyrochroa coccinea (Fred Kohler, Germany)

live larva and adult images of the palearctic genus Pyrochroa (Malcolm Storey, UK)