46 INSECTS INJURIOUS TO VEGETATION. 



My knowledge of the habits of the others is not sufficiently per- 

 fect to render it worth while to insert descriptions of them here. 

 The concealed situation of the grubs of these beetles, in the 

 trunks and limbs of trees, renders it very difficult to discover and 

 dislodge them. When trees are found to be very much infested 

 by them, and are going to decay in consequence of the ravages of 

 these borers, it will be better to cut them down, and burn them 

 immediately, rather than to suffer them to stand until the borers 

 have completed their transformations and made their escape. 



Closely related to the Buprestians are the Elaters, or spring- 

 beetles (Elateridje), which are well known by the faculty they 

 have of throwing themselves upwards with a jerk, when laid on 

 their backs. On the under-side of the breast, between the bases 

 of* the first pair of legs, there is a short blunt spine, the point of 

 which is usually concealed in a corresponding cavity behind it. 

 When the insect, by any accident, falls upon its back, its legs are 

 so short, and its back is so convex, that it is unable to turn itself 

 over. It then folds its legs close to its body, bends .back the 

 head and thorax, and thus unsheaths its breast-spine ; then by 

 suddenly straightening its body, the point of the spine is made to 

 strike with force upon the edge of the sheath, which gives it the 

 power of a spring, and reacts on the body of the insect, so as to 

 throw it perpendicularly into the air. When it again falls, if it 

 does not come down upon its feet, it repeats its exertions until its 

 object is effected. In these beetles the body is of a hard con- 

 sistence, and is usually rather narrow and tapering behind. The 

 head is sunk to the eyes in the forepart of the thorax ; the an- 

 tennae are of moderate length, and more or less notched on the 

 inside like a saw. The thorax is as broad at base as the wing- 

 covers, it is usually rounded before, and the hinder angles are 

 sharp and prominent. The scutel is of moderate size. The legs 

 are rather short and slender, and the feet are five-jointed. 



The larvse or grubs of the Elaters live upon wood and roots, 

 and are often very injurious to vegetation. Some are confined to 

 old or decaying trees, others devour the roots of herbaceous 

 plants. In England they are called wire-worms, from their slen- 

 derness and uncommon hardness. They are not to be confounded 

 with the American wire- worm, a species of lulus, which is not a 



