INSECTS INJURIOUS TO CURRANT AND GOOSEBERRY 421 



half of the abdomen is reddish-orange and the rest is black. The 

 adults are abroad in May, but are very shy and are seldom seen. 

 They are saw-flies in the truest sense of that term, for the female 

 makes most effective use of her saw-like ovipositor, as has been 

 very interestingly described and illustrated by Professor Slinger- 

 land. The ovipositor is thrust into the cane for its whole length, 

 and through it the egg is deposited in the pith. The egg is an 

 elongate-oval shape, yellowish-white, and about one-twenty-fifth 

 inch long (Fig. 353d). Immediately the female moves an inch 

 or two higher and girdles 

 the stalk by numerous 

 thrusts of her ovipositor, 

 which is thrust in and then 

 given a twist to one side 

 so that it comes out at 

 one side of where it was 

 forced in, and makes a hori- 

 zontal cut. The eggs are 

 laid in late May and early 

 June and hatch in about 

 eleven days. The young 

 larvae bore into the pith, but 

 the tunnel rarely extends 

 over six inches below the 



point girdled. The full- FIG. 354. Currant stem girdled by the 

 grown larva is hardly one- stem-girdler. (After Slingerland.) 



half inch long, of a- glistening straw-yellow color, with darker head. 

 The thoracic segments are wider than the others and bear rudimen- 

 tary feet, and from the tip of the stout, cylindrical abdomen projects 

 a horny, brown bifid spine. In the fall the borer cleans out its 

 burrow at the lower end and eats a hole through the woody wall 

 of the stem to ther outer bark, which sinks in at this point. The 

 grub then spins a thin silken cocoon about itself, in which it 

 hibernates over winter, transforming to a whitish pupa in April, 

 from which the adult emerges early in May. The girdling of 

 the stalks is the principal injury, and those which harbor the pest 

 may be recognized, even in winter, by the characteristic dead 

 stubs, cut off squarely at the upper end. 



