76 



MANUAL OF VEGETABLE-GARDEN INSECTS 



The Bean Aphis 



Aphis rumicis Linnaeus 



This black plant-louse is widely distributed throughout the 

 greater part of the subtropical and temperate regions of the 



world. Its summer food 



plants 

 \'arietv 



include 

 of 



ereat 



Fig. 51. — Winged viviparous female 

 bean aphis (enlarged). 



vegetable 

 crops : beans, especially 

 the broad bean, lima bean, 

 beet, pea, celery, aspar- 

 agus, orach, onion, leek, 

 rhubarb and horse-radish. 

 In England it has been 

 reported as attacking 

 turnip and parsnip. It 



is almost certain to be found in great abundance on nasturtium 



late in the season. Its common wild food plants are dock, 



burdock, lamb's quarters, shep- 

 herd's purse and pigweed. 

 The winter is passed in the 



egg stage on Evonymus,syringa, 



snowball and Deutzia. The 



egg is about g-V inch in length 



and shining black in color. The 



eggs hatch in early spring and 



the first generation develops on 



the tender foliage of these shrubs. 



When mature, the stem-mothers, 



as the aphids of the first gen- 

 eration are called, give birth 



to living young, a few of which 



acquire wings. In the third j^io. 52.- vvmgi.ss vuip irons 



generation a larger proportion 



female bean aphis (X 20). 



