Click beetle

Elateridae or click beetles (or "typical click beetles" to distinguish them from the related families Cerophytidae and Eucnemidae, which are also capable of clicking) are a family of beetles. Other names include elaters, snapping beetles, spring beetles or skipjacks. This family was defined by William Elford Leach (1790–1836) in 1815. They are a cosmopolitan beetle family characterized by the unusual click mechanism they possess. There are a few other families of Elateroidea in which a few members have the same mechanism, but most elaterid subfamilies can click. A spine on the prosternum can be snapped into a corresponding notch on the mesosternum, producing a violent "click" that can bounce the beetle into the air. Clicking is mainly used to avoid predation, although it is also useful when the beetle is on its back and needs to right itself. There are about 9300 known species worldwide, and 965 valid species in North America. Leach took the family name from the genus Elater, coined by Linnaeus in 1758. In Greek, ἐλατήρ means one who drives, pushes, or beats out. It is also the origin of the word "elastic", from the notion of beating out a ductile substance. Some click beetles are large and colorful, but most are under two centimeters long and brown or black, without markings. The adults are typically nocturnal and phytophagous, but only some are of economic importance. On hot nights they may enter houses, but are not pests there. Click beetle larvae, called wireworms, are usually saprophagous, living on dead organisms, but some species are serious agricultural pests, and others are active predators of other insect larvae. Some elaterid species are bioluminescent in both larval and adult form, such as those of the genus Pyrophorus. Larvae are elongate, cylindrical or somewhat flattened, with hard bodies, somewhat resembling mealworms. The three pairs of legs on the thoracic segments are short and the last abdominal segment is, as is frequently the case in beetle larvae, directed downward and may serve as a terminal proleg in some species.