SHEATH-WINGED INSECTS 



685 



the " mucro," which lies in a sheath. When the beetle falls over, it arches its body into the 

 form of a bow, resting only upon the head and the extreme tip of the abdomen, removes the 

 spine from its sheath, and then drives it sharply back again. The result is that the central 

 part of the body strikes the ground with such force that the insect springs into the air to a 

 height of 2 or 3 inches. Then, turning half over as it falls, it alights on its feet. 



The FlRE-FLY of the tropics belongs to the same group. The luminosity of this insect 

 proceeds from two different parts of the body, a brilliant yellowish-green light shining out 

 through two transparent window-like spots on the thorax, while an orange glow is visible on 

 the lower surface of the abdomen. The exact cause of the light is unknown, as is also the 

 manner of its control by the 

 insect. 



The same may be said 

 of the common GLOW-WORM, 

 in which the light proceeds 

 from the lower surface of 

 the hind part of the body. 

 The male of this insect is 

 winged; the female is grub- 

 like in appearance and wing- 

 less. The grub itself, which 

 may be found in autumn, is 

 also luminous, and feeds upon 

 snails. 



Another group includes 

 a very large number of beetles 

 of very varying character and 

 appearance. Among these are 

 the OIL-BEETLES, so called 

 from their habit of exuding 

 small drops of an oily liquid 

 from the joints of their limbs 

 when handled. The eggs are 

 laid in batches of several 

 thousand in holes in the 

 ground, and the little long- 

 legged grubs, on emerging, 



'I.;!,,',. '.' ''I.''. 



[Shtffitld 

 Photo bj B. H. Btntlv~\ 



COCKCHAFER ON DAISY 



very destructive insect vhich feed* on the lu~ of tree*. The I* devours the ro, ti of 

 plants, and it often so flent.ful as to cause -very *nou mtclutj 



and hide themselves among 

 the petals to await the coming 

 of a bee. When one of the 

 latter appears, two or three of 



the grubs cling to its hairy _ , , 



body and are carried back to the nest, in which they live as paras.tes. One of 

 may be seen commonly upon grassy banks in early spring. 



Allied to these insects is the BLISTER-BEETLE, or SPANISH FLY, so well known 

 in medicine. It is a very handsome species, of a bright golden-green colour, 

 found in Great Britain on the foliage of ash-trees. In many parts of 



extremely abundant. \\7~mrrt c *rf> rharacterised as 



The beetles belonging to the large and important group of JEKVILS are ch ^^ 

 a rule, by the fact that the head is prolonged into a more or J 0* a 



or "rostrum," at the end of which the jaws are situated. The numb 

 known is above 20,000. 



