GRUBS IN STEM OR SHOOT 



247 



spring by puncturing the new wood. The part injured later develops 

 into a gall an inch or an inch and a half long, wliich shows a deep 

 scar on one side. Eggs are laid in the punctures, and grubs develop 

 in the pith of the cane. The adults come out in late sununer, and hide 

 in rubbish over winter. 



Since the beetles feed to some extent on the leaf and stem tissues, 

 they may be poisoned by spraying with arsenate of lead or Paris green. 

 Galls should be cut off and destroyed before the time of emergence of 

 adults in late summer. 



The Grapevine Girdler (Ampeloglypter ater Lee.) 



This insect in its adult stage is similarto the grape-cane gall-maker, 

 but its color is black. It injures terminal shoots by girdling them, 

 so that the end of the shoot later falls to the ground. The young or 

 grub develops within the shoot. The 

 adult emerges in the fall and hibernates 

 in the leaves or trash. 



Spraying with arsenate of lead or 

 Paris green in May or June will kill 

 the beetles. In early summer cut off 

 the ends of canes showing the charac- 

 teristic girdling, making the cut a few 

 inches below the girdle. 



The Blackberry Pithy-gall 

 (Diastrophus turgidus Bass.) 



Curious, hard enlargements of the 

 canes of blackberries are caused by 

 small, fleshy larvae which hatch from 

 eggs laid by a black gall-fly. Several 

 larvae inhabit each gall, remaining 

 within it as pupae over winter. The 

 species is not abundant enough to be a pest, but galls should be re- 

 moved whenever found. 



Fig. 327. — The Blackberry 

 Pithy-gall. Original. 



