ATTACKING THE LEAVES. 331 



roots of young cabbage-plants ; it is about one-third of an inch 

 long, white, with a dusky line on the anterior half of its body. 

 The head is pale brown, and on the posterior extremity is a 

 brown spot equal to the head in size. When the larva reaches 

 maturity, it forms a little earthen cocoon near its feeding- 

 place, and in this transforms to a pupa (Fig. 344) of a whit- 

 ish color, from which, in a few days, the beetle appears. 



The remedies recommended for the spotted Paria, No. 196, 

 are equally applicable in this case. 



No. 198. The Canadian Osmia. 

 Osmia Canadensis Cresson. 



This is a small four-winged insect which occasionally proves 

 destructive to strawberry-plants. In Fig. 345 it is shown much 

 magnified; its natural size is 

 indicated by the short line at FlG> 345 ' 



the side of the figure. The 

 head, thorax, and abdomen in 

 both sexes are green, and more t| 

 or less densely covered with 

 short hairs, those on the tho- 

 rax being longest. The wings 

 are nearly transparent, with 

 blackish veins. The female 

 is larger than the male. 



These insects nibble away the leaves, chewing the fragments 

 into a sort of pulp, and carrying it away to be used in the 

 construction of their nests. The injury done to strawberry- 

 plants by them is sometimes very marked. 



No. 199. The Strawberry Leaf-stem Gall. 



This is an elongated gall, an inch or more in length, found 

 on the stalk of the leaf of the strawberry near its base, pro- 

 duced by an undetermined species of gall-fly. Its surface is 

 irregular and its color red, while the internal structure is 

 spongy. If these galls are opened about the middle of July, 



