STERNOXIA  .—ThiS is an important tribe of beetles, including families with four malpighian tubes and only five or six abdominal sterna, while in the

thorax there is a backwardly directed process of the prosternum that fits into a mesosternal cavity . The larvae are elongate and worm-like, with short legs but often with hard strong cuticle . The Elateridae or click beetles (fig . 18) have the prosternal process C just mentioned, capable of movement in and out of the mesosternal cavity, the beetles being thus enabled to leap into the air, hence their popular name of " click-beetles " or " skip-jacks.' 'The prothorax is convex in front, and is usually drawn out behind into a prominent process on either side, while the elytra are elongate and tapering . b c a Many of the tropical American Elateridae emit light from the spots on the prothorax and an area beneath the base of the abdomen; these are " fireflies " (see above) . The larvae of Elateridae are elongate, worm-like grubs, with narrow bodies, very firm cuticle, short legs, and a distinct anal proleg . They are admirably adapted for moving through the soil, where some of them live on decaying organic matter, while others are predaceous . Several of the elaterid larvae, however, gnaw roots and are highly destructive to farm crops . These are the well-known' " wire-worms " (q.v.) . The Buprestidae are distinguished from the Elateridae by the immobility of the prosternal process in the mesosternal cavity and by the absence of the lateral processes at the hind corners of the prothorax . Many tropical Buprestidae are of large size (fig . 19), and exhibit magnificent metallic colours; their elytra are used as ornaments in human dress .

The larvae are remarkable for their small

head, very broad thorax, with reduced legs, and narrow elongate abdomen . They feed by burrowing in the roots and stems of plants .