Click beetle
From Wikipedia, the free encyclopedia
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 Eyed elater, Alaus oculatus
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Many, see text. |
Click beetles (family Elateridae), sometimes called elaters, Skipjack, Snapping, or Spring Beetle, are a cosmopolitan family characterized by the unusual click mechanism they possess; there are a few closely-related families in which a few members have the same mechanism, but all elaterids can click. A spine on the prosternum can be snapped into a corresponding notch on the mesosternum, producing a violent "click" which 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 7000 known species.
Click beetles can be large and colorful(some are brilliant metallic green), but most are small to medium-sized (<2 cm) and dull. The adults are typically nocturnal and phytophagous. In hot weather, they are prone to enter people's houses at night if entries or windows are left opened. The larvae of a few species, called wireworms, can be serious pests of corn and other grains, especially after a field has been left fallow.
Wireworms are slender, elongate, cylindrical or somewhat flattened, and relatively hard-shelled for larvae. The three pairs of legs on the thoracic segments are short and the last abdominal segment is, as is frequently the case in beetle grubs, directed downwards to serve as a terminal proleg. The posterior end of the body is acutely pointed in the larvae of the species of Agriotes that are the best known of the wireworms, but in another common form (the grub of Athous haemorrhoidalis) the tail is bifid and beset with sharp processes. They may pass a long life (two or three years) in the soil, feeding on the roots of plants, and they often cause much damage to farm crops of all kinds, but especially to cereals. The subterranean habits of wireworms make it hard to exterminate them when they have once begun to attack a crop, and the most hopeful practice is, by rotation and by proper treatment of the land, to clear it of the insects before sowing. Passing easily through the soil on account of their shape, wireworms travel from plant to plant, and thus injure the roots of a large number in a short time. Other subterranean creatures such as the leather-jacket grub of crane flies which have no legs, and geophilid centipedes, which may have over two hundred, are often confounded with the six-legged wireworms.
[edit] Partial List of Genera
Actenicerus
Adrastus
Aeolus
Agriotes
Agrypnus
Alaus
Ampedus
Anchastus
Anostirus
Aplotarsus
Athous
Berninelsonius
Betarmon
Brachygonus
Brachylacon
Calambus
Cardiophorus
Chalcolepidus
Cidnopus
Conoderus
Crepidophorus
Ctenicera
Dacnitus
Dalopius
Danosoma
Denticollis
Diacanthous
Dicronychus
Dima
Drasterius
Eanus
Ectamenogonus
Ectinus
Elater
Eopenthes
Fleutiauxellus
Hemicrepidius
Horistonotus
Hypnoidus
Hypoganus
Hypolithus
Idolus
Ischnodes
Itodacne
Lacon
Limoniscus
Limonius
Liotrichus
Megapenthes
Melanotus
Melanoxanthus
Metanomus
Negastrius
Neopristilophus
Nothodes
Oedostethus
Orithales
Paracardiophorus
Paraphotistus
Peripontius
Pheletes
Pityobius
Podeonius
Porthmidius
Procraerus
Prodrasterius
Prosternon
Pseudanostirus
Pyrophorus
Quasimus
Reitterelater
Selatosomus
Sericus
Simodactylus
Stenagostus
Synaptus
Zorochros
This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain.
