Thk Currant-Stem Girdi^er. 45 



observant currant growers in the winter. Thus one phase of the 

 work of this insect — its girdling habit — fortunately makes it a 

 comparatively easy matter to ascertain whether it is present in a 

 currant plantation or not, either during the growing season or in 

 the winter. 



The Insect's Appearance. 



Although the insect makes its presence known in the con- 

 spicuous manner shown in the frontispiece, it is so shy that no one 

 has ever caught the girdler at its destructive work on the bushes 

 in the field. Thus currant growers will rarely, if ever, meet with 

 the adult insect — the saw-fly — which does the girdling. How- 

 ever, many will be interested to know how the ingenious girdler 

 looks. Both sexes are therefore shown, natural size, at the right 

 of the much enlarged figures of the same at a, plate III. The 

 insect is one of the saw-flies and is thus closely allied to the 

 parents of the well-known " green- worms," which every currant 

 grower has to fight almost annually. They are called saw-flies 

 from the fact that they have a saw-like ovipositor ; it is quite a 

 formidable affair in the case of the currant stem-girdler, as figure 

 b, plate III shows. The uses to which this insect puts this saw- 

 like instrument are discussed further on. 



As the figures show, the male insect is somewhat smaller than 

 the female, and it also differs somewhat in its coloring ; both are 

 pretty little saw-flies with shining black bodies and light brown- 

 ish-yellow legs. In the male, nearly all of the abdomen is of a 

 brownish-yellow color, while in the female the first half of the 

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

 mouth-parts, in both sexes, are of a light lemon-yellow color, and 

 similarly colored markings occur on the thorax around the bases 

 of the wings. ^ The adults fly in May, and perhaps some currant 

 growers may be fortunate enough to see some of the shy little crea- 

 tures. The other stages of the insect — its ^%%, the grub, and the 

 pupa — are to be found only in the currant shoot below where it was 

 girdled. To see them one must split open the injured shoots at 

 certain times during the summer. These earlier stages of the 



*For detailed specific descriptions of both sexes see Insect Life, VI, 300. 



