426 BUSH-FBUITS 



The Currant Stem-girdler 



Janus integer (Norton). — Order Hymenoptera. Family UroceridaB. 



Slingerland, Bull. Cornell Univ. Exp. Sta., 126 : 41. Cephus integer. Nor 

 ton, Proc. Bost. Soe. Nat. Hist., 8 : 224. Janus Jlaviventris, Fitch. 

 N. y. Rept., 7 : 12. Lintner, N. Y. Rept., 4 : 47.-8 : 166. Fhyllcecus 

 flaviventris (Fitch). Marlatt, Ins. Life, 6 : 296.-7 : 387. 



This, too, is a native saw-fly, but the larvse, instead of feeding 

 on the leaves, like the others, burrow in the pith of the currant 

 stems. The egg is laid within the pith of the young shoots a few 

 inches from the tips. After depositing the egg the female fly 

 moves upward and proceeds to girdle the stem at a point from half 

 an inch to an inch above where the egg was placed. The cane 

 may be entirely severed by this girdling, or may still cling by a 

 small portion, but quickly wilts, and generally soon falls away. 

 The larva, which is nearly half an inch long at maturity, burrows 

 downward, eating out the pith as it goes, and leaving its channel 

 filled with dark brownish refuse. Toward autumn it eats a pas- 

 sage way to the outer bark, wraps itself in a thin silken cocoon 

 and passes the winter in the lower end of its burrow. In the 

 spring it changes to a pupa, and thence emerges as a perfect in- 

 sect in May. It is then a shining black fly, with the hind part of 

 the body and front of the abdomen yellow, measuring about half 

 an inch in length by three-fourths of an inch in breadth, with the 

 wings extended. 



Remedies. — Cutting out and burning all injured tips is an effi- 

 cient and practical remedy. The larvae rarely get more than six 

 inches below where the egg is laid, and this being only an inch 

 or so below the girdle, cutting away eight inches of the stem at 

 any time during the summer or winter, will destroy the insect. 

 If done soon after the girdle is made two or three inches will 

 suf&ce. The larvae may readily be found by splitting open the 

 cane. Many eggs fail to develop, and the young larvae often 

 perish before attaining their growth. This checks their increase, 

 but does not affect the injury for the current year. The larvae 

 are subject to attack from hymenopterous parasites. In one 

 case Professor Slingerland (loc. cit.) saw five tiny parasites 

 (Bracon apicatus, Prov.) emerge from a single cocoon. 



