406 Report of the Entomologists of the 



the insecticide, and thus escape being killed. Where headed 

 cabbage, which throws out no new leaves, is left standing on the 

 field they eat into the solid heads. During the day they usually 

 feed from the under or lower surface of a leaf, but probably they 

 do the most of their feeding at night. The habit of feeding from 

 the under side of a leaf gives them a chance to hide and at the 

 same time be protected from the sun. When feeding upon such 

 plants as carnations they hide during the day in a position to 

 resemble a leaf or branch of the plant. They are sure to find 

 the most tender portion of a plant such as the buds and growing 

 tips. They like nothing better than to feed upon the flower of 

 a cauliflower after it has been tied. Their appetites are gener- 

 ally good. A medium-sized looper will devour a lettuce plant 

 having 4 or 5 leaves in one night. They can travel quite rapidly 

 and easily pass from one plant to another. 



CONCLUSIONS. 



Cabbage worm. — The fact that the eggs are deposited on the 

 under or outer side of the leaf, and, that the worms do their 

 first feeding on that part of the leaf, in fact in most cases feeding 

 upon the under or lower surface of the leaves until nearly half 

 grown, makes it essential that any poisonous insecticide should 

 be on that part of the leaf to give complete results. The habit 

 of feeding from the lower side of the leaves makes the use of 

 all insecticides which kill by contact more or less impractical, at 

 least until after the worms have done a large amount of dam- 

 age. This habit is also often the cause of delay in treatment 

 as they are not noticed until many of the worms are through feed- 

 ing and ready to pupate. 



The fact that the broods overlap so that eggs and full grown 

 worms occur on the plants at the same time, assuming all other 

 conditions to be favorable, makes it impossible to destroy them 

 all with one treatment with any of the measures that have been 



