22 MANUAL OF VEGETABLE-GARDEN INSECTS 



slightly flattened eggs in eonipaet clusters of 125 to 150 or 

 more on the underside of the leaves. The eggs hatch in a 

 week or two and the young caterpillars feed for a time in 

 colonies, skeletonizing the leaves, but later scatter and feed 

 singly. They are at first nearly black but soon become pale 

 or greenish and then develop the characteristic markings of 

 the mature larva. There are two generations a year, the 

 first brood of caterpillars being found in June and July and the 

 second in the fall. The insect may hibernate either as partly 

 grown caterpillars or in the pupal stage. 



The zebra caterpillar rarely becomes sufficiently abundant to 

 require remedial measures on crops grown under commercial 

 conditions. The young caterpillars may be killed by spraying 

 with paris green or arsenate of lead. In the home garden 

 hand-picking is the most satisfactory remedy. 



A closely related species, Mamestra legitima Grote, sometimes 

 known as the striped garden caterpillar, has been reported as 

 a general feeder on vegetable crops in the District of Columbia 

 and in Georgia. The larva of this species differs from the zebra 

 caterpillar in .having the stigmatal yellow stripe broadly 

 bordered with black above. In habits and life history, the 

 two species are similar. 



. The Cabbage Aphis 



Aphis hrassiccp Linnaeus 



The cabbage aphis is supposed to be of European origin, 

 but now occurs over practically the whole world wherever its 

 food plants are cultivated. It attacks cabbage, cauliflower, 

 brussels • sprouts, kohlrabi, collard, kale, brocolli, rape, turnip 

 and radish. It also breeds to a considerable extent on a number 

 of wild plants belonging to the mustard family. In the United 

 States, especially in the northern and eastern states, it often 

 takes first rank as an enemy of cabbage, cauliflower and related 



