ATTACKING THE LEAVES. 373 



of the young growing shoots, often depriving them entirely 

 of foliage. 



No. 233. The Cranberry Saw-fly. 

 Pristiphora identidem Norton. 



This insect, which is closely allied to the imported currant- 

 worm, No. 205, is destructive to cranberry-vines on Cape 

 Cod. The perfect insect is a saw-fly, the female having a 

 toothed ovipositor, with which she makes a slit in the leaves, 

 depositing an egg therein. Broods of the larvae appear early 

 in June, and again in August. When first hatched, they are 

 pale yellowish green, but become darker with age ; the head 

 is black in the young specimens, lighter in the full-grown 

 ones. When mature, they measure about three-tenths of 

 an inch long, are cylindrical and smooth, with two lighter, 

 whitish-green stripes running the whole length of the body. 

 Towards the end of June they spin their cocoons among 

 withered leaves or other rubbish, from which flies are pro- 

 duced about ten days afterwards. 



The perfect insect has the body black, the legs marked 

 with yellowish red and black, the wings transparent, with 

 black veins. 



No. 234. The Cranberry Gall-fly. 



Cecidomyia Sp. 



About the middle of June the small leaves at the tips of the 

 growing shoots may often be fdund fastened together. Within 

 these clusters is a small, pinkish or orange-colored larva, 

 having the form shown at 6 in Fig. 386, which is without 

 legs, and when first hatched is white. This larva spins a 

 cocoon (see a in the figure), which resembles white tissue- 

 paper ; this is formed among the small leaves at the end of 

 the shoot, and within it the insect changes to a pupa, as 

 shown at c. 



In about twelve days the perfect insect, a gall-gnat, appears 

 (see c?, Fig. 386 ; e represents the antenna of the female, much 

 enlarged). This gnat is found in almost every cranberry- 



