3G2 



NATURAL HISTORY. 



CHALCOPHORA MARIANA. 



sterna. Their antennae are received in repose in narrow furrows existing for their protection in tho 

 bides of the prosternum, and their feet are contractile. About a hundred species are known, chiefly 



from South America. The EUCNEMID.E are distinguished by 

 their nearly cylindrical form, and the close approximation of 

 the cavities in which the antennae are inserted, which has the 

 effect of greatly contracting the forehead. The antennae are 

 often beautifully branched. Nearly 500 species are known, 

 p* chiefly from tropical countries. The ELATERID.E are more 

 abundant in temperate latitudes than either of these two 

 families, the species of Great Britain being familiarly known 

 as " Click-beetles," from their singular habit of springing up in 

 the air with a clicking noise when held in the hand on their 

 backs, and thus, by reversing themselves, recovering the walking 

 position. This action is produced by a vigorous tension of tho 

 muscles connecting the prothorax with the hind body, which 

 raises the back above the surface on which the body lies, followed by a sudden relaxation, which brings 

 it down again with force sufficient to make the insect bound into the air. The long, narrow, and 

 flattish body, and the short and slender legs of these Beetles, render it otherwise very difficult, or 

 even impossible, for them to turn over when by any accident they are cast on their backs. In accordance 

 with this peculiar habit the sterna are not permanently interlocked, as in the Buprestidse, but the 

 long spine of the prosternum and the corresponding groove of the middle breast play a necessary 

 part in the saltatory movement, in bringing the parts together after the strain and elongation 

 of the thoracic muscles, the groove helping to guide the projecting 

 point into the true axial position immediately the insect brings its 

 prothorax down again and bounds upwards. 



The Elateridse are well known also in their larva stage as the 

 Redoubtable Wireworms of our farmers and gardeners. These derive 

 itheir name from their long, slender, cylindrical, somewhat rigid 

 forms, so different from the club-shaped grubs of the Buprestidse. 

 feeders, abounding often in rotten stumps ; but many species are root-gnawers, and in this capacity 

 attack all sorts of cultivated vegetable produce the grass of lawns, cereals, and the plants of our 

 gardens. Some of the species have been observed to live three years in the larva state, and to do in 

 this time great damage to crops of corn. 



A remarkable faculty of one group of these insects is their luminosity : the Fire-fly of the West 

 Indies and South America belonging to this family, and not to the true Glowworms. The light is 

 emitted from two rounded spots on the prothorax, which are covered with a thinner 

 and paler horny coating than the rest of the integument. Underneath each of these 

 lamp-covers, within the thorax, is a vesicle of phosphorescent substance, which is 

 luminous or not according to the will of the insect. The fire-flies belong to the genus 

 Pyrophorus, and about ninety species are known from North and South America, 

 differing in the degree of luminosity, some being destitute of lamps visible on the 

 exterior. They are all night-flyers, and much less abundant than the true Glow- 

 worms of the same countries. The light is in some species emitted from the membranoiis 

 parts at the articulation of the segments of the thorax, as well as from the rounded 

 spots on the surface. Luminous Elateridte, distinct as a genus from Pyrophorus, are 

 found also in the New Hebrides Islands in the South Pacific. The larva of an Elater 

 of the genus Melanactes, found in the United States, is also phosphorescent. We 



JUMPING ORGAN ' . ' A1 1 * 1 1 



OF ELATEK. "gure one of the Pyroplion. and also a JNorth American species, Alaus ocnlatus, which 



has two eye-like spots on the prothorax, but is not luminous. 



Allied to the Elateridae are the two families CEBRIOMD.E and RHIPICERID.E, the latter of which 

 has in the males beautifully branched, sometimes fan-like or flabellated, antennae. The middle 

 sternum has no groove for the reception of a projection of the fore sternum. A few species only are 

 known of either family, and none occur in the British Islands. 



ELATER PKEPAIUNG TO SPUING. 



They are generally wood- 



