THE SQUASH BUG 



241 



the fruit itself. This injury to the fruit causes decay. In some 

 localities this insect is a serious pest to cucumbers, squashes, 

 and melons. It destroys the blossoms, mines the stems, and bores 

 into the ripening fruit. 



Control. Since the injury is worse in late summer, it is ad- 

 visable to plant early and also to grow early maturing varieties 

 of the vegetables which this worm seeks. All litter on the field, 

 including old vines, should be destroyed after harvest. Since these 

 pests prefer to lay eggs on the squash, this plant may be used as 



FIG. 249. The 12-spotted Diabrotica, different stages, details of structure and injury. 

 Hair lines indicate actual size. (U. S. Bu. Ent.) 



a trap crop, if melons or cucumbers are to be protected. For 

 example, one might plant rows of summer squash through cucum- 

 ber or melon fields at an early date, planting every two weeks, so 

 that some would be in flower during July. The flowers could be 

 collected and destroyed with the contained larvae at frequent 

 intervals. This method of control has been carefully tested and 

 found to give almost complete protection to muskmelons. Arseni- 

 cal sprays are of little value. When possible, change the location 

 of plants each year. Collect and destroy badly infested fruit 

 whenever it is observed. 



The Squash Bug (Anasa tristis DeG.). The adult bug is a 

 16 



