THE ANIMAL FOOD OF BIRDS. 



45 



Ui ISE LEAF-HOPPEK. 

 Magnified. 



creatures with elongate-oval bodies and hind legs fitted for 

 jumping. An idea of their appearance may be obtained from 

 the accompanying picture, which represents the well-known 

 rose leaf-hopper. The adult of this species is about one-tenth 

 of an inch long, with a yellowish-white 

 body and white semi-transparent wing- 

 covers. It injures the rose-leaves by suck- 

 ing out the cell contents, giving the upper 

 surface a white-spotted appearance. One 

 or more members of this family live upon 

 a large proportion of the flowering plants, 

 both wild and cultivated, and often do 

 serious damage. 



None of the true bugs are so constantly 

 and generally injurious as the plant-lice, or 

 aphides, which form the family AphididoR. 

 The common "green fly 1 ' of house plants 

 is an example of this group, and nearly every cultivated crop 

 is subject to the attack of one or more species. The normal 

 life-history of these little creatures may be briefly outlined in 

 this way: In the spring there hatches from an egg deposited 

 the autumn previous a little plant-louse that sucks the sap of 

 its food-plant for a number of days — sometimes for a fort- 

 night — before it becomes fully grown. During this period of 

 growth it moults, or sheds its skin, a number of times, to 

 provide for its rapidly increasing size. This plant-louse, 

 which developed from the egg, is often called the "stem- 

 mother :" she is always wingless. Soon after reaching ma- 

 turity she commences to give birth to living young, con- 

 tinuing the process for several days. These young resemble 

 the stem-mother in general appearance, being, of course, 

 much smaller. Each soon begins sucking sap on her own 

 account, and in the course of ten days or a fortnight be- 

 comes mature and commences to bring other living aphides 

 into the world ; the latter soon mature and give birth to a 



