THE GEANTJLATED CUTWORM. 13 



prevent injury and besides the expense of placing these barriers 

 around the plants, their presence may retard the growth of the plants. 

 In the experiments larvae sometimes ascended the barriers, either 

 when the stems were wrapped with the material or when the barrier 

 was at some little distance from the stem. If food plants, unpro- 

 tected by barriers, are present there is less damage to the protected 

 plants than is the case when only protected plants can be reached. 

 This is shown in Plate IV, A, B, D. The plants protected by the 

 cans, containers such as canned goods are sold in, with the tops and 

 bottoms removed, show no injury, while the unprotected plants have 

 been seriously fed upon. 



POISONED BAITS. 



Satisfactory results have been obtained in destroying the larvae 

 in cages and in the field with poisoned bran mash. A mixture made 

 up in the following proportions has given good results : 



Bran pouncls__ 10 



Molasses quart 1 



Paris green pound 1 



Water quarts 7 



Juice and finely chopped rind and pulp of 2 oranges. 



In cages where young cabbage plants were growing larvae were 

 observed to feed upon this poisoned mash after it had been scattered 

 thinly over the soil. No damage to the plants was noted and larvae 

 were dead on the following day. Of 202 larvae collected from the 

 soil 88 per cent were dead within three days after the mixture had 

 been scattered over a field of Brussels sprouts that were being in- 

 jured. A portion of the remainder apparently were not killed be- 

 cause they had completed their growth and stopped feeding before 

 the poisoned mash was put out. 



A mixture of 20 pounds of bran, 2 pounds of powdered arsenate 

 of lead, \ gallon of molasses, and about 14 quarts of water has also 

 given good results in killing larvae in the field. 



When the larvae are found to occur in abundance in a field at plow- 

 ing time and this field is to be immediately planted, it would seem 

 advisable to apply poisoned baits before the field is planted rather 

 than to wait until the crop shows injury. 



TREATING PLANTS WITH ARSENICALS. 



When the larvae are feeding upon the leaves of plants it is pos- 

 sible to reduce their numbers by applying arsenicals to the foliage. 

 This method is especially applicable in the case of plants that have 

 reached a considerable size, and under certain conditions the ar- 

 senical may at the same time prevent injury by other leaf-eating 

 insects. Plate V shows two boxes of cabbage plants. The plants in 



