126 MANUAL OF VEGETABLE-GARDEN INSECTS 



the same season. The dark brown pupa is about f inch in 

 length; its head is armed with a sharp horn-Uke process by 

 means of which it cuts its way out of the cocoon. After leav- 

 ing the cocoon, the pupa works itself up to the surface of the 

 ground in order to permit the escape of the moth. In the 

 Gulf states the insect has normally two broods ; in the latitude 

 of Washington the second brood is only partial while farther 

 north, in New Jersey and on Long Island, the second brood is 

 much smaller, and still farther north there is only one genera- 

 tion annually. 



Control. 



The squash-vine borer cannot be controlled by applications 

 of insecticides, but it may be held in check by practicing such 

 of the following methods as are warranted by the severity of 

 the outbreak or by other local conditions. As the insect passes 

 the winter in the ground, it is not good policy to grow squashes 

 in the same field year after year. If for any reason it is neces- 

 sary to raise successive crops of squashes on the same ground, 

 the land should be harrowed in the fall to expose the cocoons 

 and then plowed deeply the following spring. In all cases the 

 vines should be collected and destroyed as soon as the crop is 

 harvested in order to prevent the late caterpillars from reaching 

 maturity. If all the growers in a locality would co-operate in 

 the early destruction of the vines, the number of moths appear- 

 ing the following spring would be greatly reduced. In some 

 cases much injury may be avoided by late planting in connection 

 with heavy fertilization to promote rapid and heavy growth. 

 In some localities the use of early squashes as a trap crop has 

 been attended with success. A few early squashes, such as 

 crooknecks, are planted early around the field and between the 

 rows of the late varieties. The moths will deposit their eggs 

 on the early squashes and the main crop, coming up later, will 

 escape the greater part of the infestation. As soon as the 



