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NATURE STUDY REVIEW [9 :4— April. 1913 



Jim SON Weed. 



changes to yellow before hatching. The ^gg period averages 

 about seven days. When the little crawlers emerge they begin 

 life by eating holes in very tender leaves. While they are rave- 

 nous feeders, the inroads which the caterpillars make on the 

 tomato or potato plants is rarely serious, for while the so-called 

 "worm" eats both green and ripe tomatoes, it lives chiefly upon 

 the foliage, and this, as a rule, is sufficiently abundant to nourish 

 a few insects without sapping the vitality of the plant. When 

 present in numbers, however, they damage the tobacco, because 

 the leaves of the plant and not its fruit constitutes the crop. 



The caterpillars are nocturnal in their habits. They feed 

 for about a month, during which time they undergo several molts. 

 When fully grown they measure from three and a half to four 

 and a half inches in length. With the exception of an occasional 

 black or brown specimen, all have green skins, surprisingly like 

 the shade of the plant on which they feed. They have large 

 spiracles, or breathing holes, along the sides of their bodies, and 

 each flaunts its caudal horn — that of Carolina bemg reddish and 



