Bugs. Spring tails. Eat wigs. 123 

 CHAPTER XXIII. 



ORDERS OF INSECTS. 



ORDER I. Bhynchota. This group consists of 

 those insects which either undergo no metamorphoses 

 or a very slight change in FIG. 70. 



the process of growth. 

 They have almost all 

 suctorial mouths (fig. 70), 

 consisting of a long tubu- 

 lar labium, whose base is 

 open or covered by the 

 labrum like a little lid. 

 The mandibles and 

 maxillae are altered into 

 piercers or bristles which 

 work within the tube. A 

 few, however, like the 

 bird-lice, have hook-like 

 mandibles and chewing 



mOUths. Many Of the Showing the median elongated labium, 

 incf^tc r\f tVn'c rvrrl^r arp tne f ur bristle-like mandibles and 



insects ot this order are maxillaet also , at ^ sideSj Ac an _ 

 parasites and wingless, tennae and * 

 such as lice and bugs ; others, the aphides, the small 

 green insects which are so abundant on roses, gera- 

 niums, &c., are plant parasites. 



These aphides are marvellously prolific, a single 

 pair being capable in one year of producing a progeny 

 of twenty thousand millions or even more. Some 

 aphides have glandular tubes on the abdomen which 

 secrete a sweet honey-like fluid. This fluid is used 



