CAPE COD CRANBERRY INSECTS 67 



in early May and the adults usually emerge soon after mid-May and lav eggs 

 so that the larvae appear on the bogs again early in June. About live gen- 

 erations occur, the last worms usually entering their winter cocoons in mid- 

 October. The worms develop so irregularly that the broods get mixed by 

 late sunuiier, all stages occurring at once. 



The E(i(j. 



The female always perches on the edge of a cranberry leaf to lay and puts 

 her eggs in pockets she makes between the upper and lower surfaces and 

 opening at the margin (fig. 67). The pockets usually are placed singly, but 

 sometimes two or more are near together. One or, rarely, two eggs are placed 

 m a pocket and often protrude a little. They are elliptical, watery greenish 

 brown, and a little over a twenty-fifth of an inch long. 



The Larva. 



At first the worms are light yellowish green with the head dark brown. 

 They grow darker with age. When mature (fig. 68) they are slightly over 

 three-eiglitiis of an inch long, smooth, green, and without noticeable markings 

 except a narrow internal stripe of whitish jiigment running the length of the 

 back on each side of the heart and conspicuous through the skin. Their iieads 

 are pale greenish brown with a black dot on each side. They have six pairs 

 of prolegs. 



The Adult. 



The flies (fig. 66) are a fiftli of an inch long and half an inch across their 

 expanded wings and mostly black, but the females have a broad band across 

 the middle of the upper side of the abdomen and all its under side l)ut the 

 tip brownish yellow. 



Treatment. 



Flooding for 1-5 hours about June 10 or for 18 days in late September and 

 early October is effective; so also is spraying with 6 pounds of dry lead 

 arsenate to 100 gallons of water early in June. 



'28. No. 1647 



