14 



ANIMAL BIOLOGY 



they are very likely to be cross-pollinated and thus are bene- 

 fited instead of injured. But in general the moths and 

 butterflies play but little part in the very important process 

 of cross-pollination of flowers, most of this work being done, 

 as we shall soon learn, by the bees. The following are a few 

 of the injurious forms of butterfly and moth larvae. 



14. Cabbage butterfly. — This is one of the few forms of butter- 

 fly larvse that are of sufficient economic importance to be worthy of 



mention. Any one who has 

 been near a cabbage patch 

 will remember to have seen 

 many rather small white but- 

 terflies (Fig. 10) hovering 

 about among the cabbages. 

 These are the cabbage but- 

 terflies depositing their eggs 

 on the imder side of the 

 leaves. The small green 

 caterpillars that develop 

 from the eggs very soon show 

 what they can do in the way 

 of eating. The ragged ap- 

 pearance of the young leaves 

 is a warning to the gardener 

 to "get busy" if he desires 

 a crop. The caterpillars do most harm when the cabbages are 

 young, since these plants may be so injured as to be unable to 

 form heads. The caterpillars are often kiUed by sprinkling with 

 a mixture of Paris green and arsenate of lead in water (47). 

 This mixture should not be used, however, after the heads begin to 

 form, on account of the possibility of the poison collecting between 

 the leaves of the head, with consequent danger to the consumer. 



15. Tussock moth. — The caterpillars of the tussock moth attack 

 oiu' shade trees. Where they are unchecked, they wiU practically 



Fig. 10. — Life history of cabbage butter- 

 fly. (Coleman.) 



