88 



FARM FRIENDS AND FARM FOES 



from the food plants and become full-grown in a very 

 short time, possibly a week or ten days. All of these 

 insects that thus hatch from the winter eggs are what are 

 known as viviparous females, because they are able to give 



PupA 



LARVA 

 SPRING GRAIN-APHIS 



[Redrawn from Webster] 



WiNGLESS 



FEMALE 



WINGED 



FEMALE 



birth to living young. Each insect produces a large 

 number of these young plant lice of the second generation, 

 and these in turn very quickly mature and give birth to a 

 third generation. This method of reproduction continues 

 throughout the spring, summer, and early autumn. On 

 account of the rapid growth and of the large number of 

 young produced by each of the viviparous females, the 

 insect is able to multiply with astounding rapidity. . 

 When the food plant is green and succulent, nearly all 



