48 PROTECTION OF PLANTS, 1917-18 



than the imported currant sawfiy {Pteronus ribesii). Some damage was done by 

 the currant span worm {Cymatophora rihearia) especially on the flowering 

 currant {Rihes cereum). 



Insects Affecting the Grape. 



The worst pest of the grape, the leaf hopper or grape thrips (Typhlocyba 

 comes), undoubtedly reduces the yield appreciably. The little hoppers are unable 

 to jump like their older fellows and succumb if hit by the nicotine sulfate or 

 "Black Leaf 40" spray, 1 to 100 of water. A good pressure is necessary and the 

 under side of the leaf should be hit by the spray. The old hoppers winter ov^er in 

 near-by sod and weeds, hence clean farming helps much to control them. 



Insects Affecting Shade and Forest Trees. 



Less common at Ste. Annes than at other points were the unsightly nests 

 of the fall web-worm {Hyphantria cimea). The ash {Fraxinus sp.) was attacked 

 severely. The hairy caterpillars are yellowish or grayish, with a broad blackish 

 stripe along the back. 



The poplar saw-fly {Trichiocampa viminalis) did some damage to the 

 Carolina poplar, where the yellow, black-dotted caterpillars worked among the 

 foliage. Then they spin a silken cocoon in the ground, and in late August is 

 seen the small four-winged sawfly with black head and thorax, and straw-yellow 

 abdomen. 



The birch chrysomelid beetle (Caligrapha scalaris) was bred from soft 

 black grubs feeding on willow. 



