New Yokk Agricultural Experiment Station. 407 



in use. In fact the combination of all conditions, makes it im- 

 possible to destroy them all with two or three treatments by any 

 of the measures previously used. 



The numerous spring food plants to be found in this section 

 make the use of trap-crops, or even the systematic spraying of 

 early cabbage, impractical and more expensive than results war- 

 rant. 



Many growers of cabbage never attempt to use remedies until 

 after they see the ravages of the worms or the worms themselves. 

 In such cases part of the worms are nearly through feeding, 

 hence the treatment is far from complete in its results. 



The numerous food plants, the varying habits of the worms 

 and butterflies in adapting themselves to conditions, their feeding 

 out of sight until quite large, combined with carelessness in the 

 methods of combating them, all aid in making, in nine cases out 

 of ten, the final results from the methods used almost nil. 



Cabbage loaper. — Undoubtedly the wariness of the looper with 

 regard to feeding on foliage that has any foreign substance on its 

 surface, combined with its activity, makes it one of the hardest 

 to combat of the leaf -eating caterpillars. In all my work I have 

 failed to find a dead looper on plants treated with remedies of any 

 form used as dry powders. Possibly a few are killed by the use 

 of dry Paris green and flour on cabbage, but they are very few. 

 Light traps have been used in forcing houses but without success. 

 The use of mosquito netting on the ventilators of forcing houses 

 has been recommended but growers think this would not only be 

 too expensive but also inconvenient and impracticable. Further- 

 more, in transplanting the first crop of lettuce from beds out of 

 doors to forcing house, the eggs of the moths and of the worms 

 themselves are carried in on the plants. If a half dozen perfect 

 female moths get into a forcing house containing 2,000 square 

 feet of bench room, they are able to deposit eggs on most of the 

 plants. Hand picking is generally practiced for this pest on 

 lettuce, but usually the rascal has a plant destroyed before he is 

 picked. 



