CHAPTER XXIII 



INSECTS INJURIOUS TO RASPBERRY AND BLACKBERRY * 

 The Raspberry Root-borer t 



THE larvae of the Raspberry Root-borer make tunnels in the 

 roots and lower stems of raspberry and blackberry, sometimes 

 completely girdling the stem at the crown, so that the name of 

 blackberry crown-borer has also been 

 used. The full-grown larva is from 1 to 

 1J inches long, yellowish-white, with 

 brownish head, and the tips of the small 

 thoracic legs also brownish. The parent 

 insect is one of the clear-winged moths, 

 which fly by day and closely resemble 

 wasps, and is nearly related to the peach- 

 and squash-borers. The female is much 

 the larger and is shown natural size in 

 Fig. 328. The body is black with yellow 

 rings, and the legs are yellowish. The 

 wings are transparent except a bronze- 

 brown margin and a narrow band across 

 the fore-wings about one-third from the 

 tip. 



Life History. The moths appear in 



late August and September and the females deposit their eggs 

 upon the lower edge of the leaves. The egg is oval, about one- 



* See F. M. Webster, Bulletin 45, Ohio Agr. Exp. Sta.; J. B. Smith, 12th 

 Report N. J. Agr. Exp. Sta. 



j" Bembecia marginata Harr. Family Sesiidce. See J. B. Smith, Bulletin 

 N, N. J. Agr. Exp. Sta., p. 9; W. H. Lawrence, Bulletin 63, Wash. Agr. Exp. 

 Sta. 



4:9 



FIG. 327. The raspberry 

 root-borer (Bembecia 

 marginata Harr.) : a, 

 male moth; b, female 

 moth natural size. 

 (After Riley.) 



