Melyridae are a family of beetle

Beetle

Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...

s of the superfamily Cleroidea

Cleroidea

Cleroidea is a small superfamily of beetles. Most of the members of the group are somewhat slender, often with fairly soft, flexible elytra, and typically hairy or scaly.It contains about 10,000 species in the families:* Acanthocnemidae Crowson 1964...

. The family Melyridae contains 520 species in 58 genera in North America. Most are elongate-oval, soft-bodied beetles 10 mm long or less. Many are brightly colored with brown or red and black. Some melyrids (Malachiinae) have peculiar orange structures along the sides of the abdomen, which may be everted and saclike or withdrawn into the body and inconspicuous. Some melyrids have the two basal antennomeres greatly enlarged. Most adults and larvae are predaceous, but many are common on flowers. The most common North American species belong to the genus Collops (Malachiinae); C. quadrimaculatus is reddish, with two bluish black spots on each elytron

Elytron

An elytron is a modified, hardened forewing of certain insect orders, notably beetles and a few of the true bugs ; in most true bugs, the forewings are instead called hemelytra, as only the basal half is thickened while the apex is membranous...

. Batrachotoxins are found in them.