THE IMPORTED CABBAGE WEB WORM. 43 



Another method was tested by Mr. Simons. He captured many 

 of the moths with the aid of a barrel having all but four of the 

 staves sawed out, leaving 4 inches from the bottom to form a 

 tub in which to hold water. From the top of this a light was sus- 

 pended which attracted the moths. In this way he caught a great 

 many insects in two seasons. The light barrels, as he terms them, 

 were placed on seed beds of cabbage. 



A thin scum of kerosene was used in this experiment, but it i's sug- 

 gested that this be eliminated in order not to destroy the predaceous 

 insects, such as ground beetles and parasites, which are practically 

 certain to be attracted. This suggestion is made in view of the 

 fact that the destruction of one beneficial ground beetle or parasite 

 is equivalent to the destruction of, perhaps, from 20 to 100 injurious 

 insects. The predaceous and larger parasitic insects can be easily 

 picked from the water, and though they may be apparently dead, it 

 will soon be seen that they recover and crawl away. The moths are 

 not apt to recover. 



There can be little doubt that Bordeaux mixture sprayed on the 

 plants when they are first set out, or when they first appear above 

 ground, and continued at intervals of a week or two, should act as a 

 deterrent of attack. It is advisable, therefore, in using an arsenical, 

 to employ Bordeaux mixture as a deterrent. Where cabbage and 

 similar plants, liable to infestation by this insect, are set out from 

 sash or cold frames, dipping the plants in a solution of arsenate of 

 lead, prepared at the rate of about 4 pounds of the arsenical to 50 

 gallons of water, should be useful. 



Among other remedies which may be suggested for employment, at 

 least on a small scale^ are the following: 



Planting an excess of seed with the aim of afterwards destroying 

 the plants which are injured by the webworm beyond redemption. 



Fall plowing, a standard remedy for many insects. 



Clean culture, or the maintenance of the cabbage or other fields 

 throughout the season free from weeds, especially cruciferous weeds, 

 and prompt destruction of dead or dying plants during the season 

 and the removal of all cabbage heads, stalks, and other refuse. All 

 cruciferous crops should be treated in a similar manner. 



The refuse material, including hopelessly injured cabbage heads 

 and other crucifers, should be gathered in piles and promptly burned. 

 The addition of straw or similar dry material will aid in ignition. 



