BEETLES. 



59 



popular name " Bombardier Beetles." In Anthia, OrapMpterus and 

 other genera the fluid is not explosive but acid, and causes pain and 

 discoloration. 



Paussidce possess the same crepitating faculty. They are curious 

 beetles which live in the nests of ants, and seem to secrete a sweet 

 substance which is very agreeable to their hosts. All the species 

 (about 300 are known) are easily recognised by the extraordinary 

 forms assumed by their antennae. 



The Gyrinidw, Whirligig Beetles, skim over the surface of ponds 

 and rivers by means of their paddle-shaped middle and hind legs. 

 The front pair form prehensile organs for seizing the insects upon 

 which they feed. The larvae live in the water. 



The Dytiscidce are adapted to a purely aquatic life, although able 

 to fly well. They carry a supply of air between the elytra and the 

 back, where the spiracles are situated. They also are predaceous. 



The Staphylinidce are very ready fliers, although their wings fold 

 into a very small space and the wing-covers are very short. They 

 include a multitude of small species, and the insects which so often 

 fly into the eyes on summer days and cause them to smart, commonly 

 belong to this group, especially species of Oxytelus. 



The Silphidce are chiefly carrion-feeders, and the species of 

 Necrophorus have the curious habit of burying small carcases which 

 they find upon the ground, by digging away the earth from beneath 

 them. Their eggs are afterwards deposited upon them and the larvae 

 feed in security. 



Coccinellidce, or Ladybirds, are amongst the most valuable of all 

 insects to agriculturists, most of them feeding both as larvae and 

 imagines upon the prolific Aphidce and Coccidce, which work havoc 

 among so many crops. When other methods of extirpating these 

 have failed in various colonies, the introduction of certain kinds of 

 Goccinellidcv has, in some cases, proved very successful. 



The Lamellicorns include many of the largest and most striking 

 insects. Many species are very destructive to trees and crops. The 

 Cockchafer, Melolontha vulgaris (see Wall-case 8, No. 129), is one 

 of these. It eats the leaves of oaks and other trees, but the larvae 

 cause still more serious damage, by destroying the roots of cultivated 

 crops. They generally pass three years in the ground before their 

 development is complete. 



Many Scambceidce are dung-feeders, like the long-familiar ball- 

 rollers of the Mediterranean, Africa and the East. The ball when 

 made is rolled with the hind legs until a sheltered spot is found 



