LIFK-HISTOKY OF A BEETLE. 171 



4, Crops are destroyed only by the cater- 

 pillar. Neither the pupa nor the perfect insect 

 can injure plants, and, as has already been 

 stated, moths and butterflies are important 

 a gents in the fertilization of many flowers. 



LIFE- HISTORY OF A BEETLE. 



1. Many destructive insects belong to 

 another order of insects, the beetles. These go 

 throagh a similar series of changes : egg, larvn, 

 (called 'grub' in this order), chrysalis or 

 pupa up to the perfect insect. The larvae of 

 beetles are often provided with three pairs of 

 jointed legs, but have no sucker-feet. Some- 

 times they are entirely without legs and are 

 then usually white and fleshy. They have 

 very strong biting jaws and the segments of the 

 body are not so well marked as in caterpillars. 



2. The pupae are inactive, often enclosed 

 in a cocoon, and in them the form of the forth- 

 coming beetle is easily recognised. 



3. The perfect insect is usually hard, 

 with two pairs of wings, of which the first pair 

 are hard and long, forming a sheath for the 

 second pair which are thin and membranous. 

 Their jaws are usually strong and well adapted 

 to biting. 



