THE INSECT WORLD. 



30.3 



bage-worm." and as they infest the plants at about the same time 

 in midsummer, one appHcation of Paris green or London purpie 

 will answer for both insects. 



Fig. 341. 



The cabbage Plusia, P. biassictz. — a, larva; b, pupa in its thin cocoon ; 

 c, male adult. 



Another series of usually bright-colored, active moths that fly 

 during the day, sometimes in the hottest sunshine, is the Helio- 

 thini, which are usually white or yellow in color, and not infre- 

 (juently have a glossy or metallic lustre. Taken altogether, the 

 species are not common, and are much more abundant both in 

 specimens and species in the West and Southwest. But we have 

 one form, abundant throughout the Eastern United States, which 

 is at once the largest, least conspicuous, and most destructive of 

 those belonging here, yielding little, in the injury it does, to any 

 other Noctuid. It is the Heliothis armiger, whose caterpillar is 

 locally known as the " boll-worm" in the South, where it bores 

 into cotton-bolls ; the " corn-worm" in the North, from its habit 

 of eating into ears of corn, and the ' ' tomato-worm' ' in some of 

 the Eastern States, from its habit of boring into tomatoes during 

 the early part of the season. The species is one of the most 

 difficult to deal with directly, from its habit of feeding concealed 

 in such a way that in most cases the application of arsenites is 

 a practical impossibility. It has been found by experience that 



