EXPERIMENT" STATION BULLETINS. 



317 



Fig. 37. — Imported Currant-worm, from Riley, Ninth Rep. State Entomologist of Mo. 



cocoon is oval in form and thin, being papery in texture. There are two broods 

 a year but they are not well defined. The adults come out at various periods, 

 necessitating a repetition of the measures required to kill the larvas. 



REMEDIES. 



The time honored practice of dusting with hellebore will ordinarily prove 

 sufficient if the hellebore be fresh. After the fruit has been picked, arsenites 

 may be used to advantage. See directions for using paris-green. 



The Native Currant Saw-fly. {Gymnonyclius appendiculatus.) 



Another species of currant-worm which is a native of America is sometimes 

 met, especially in the north. It occurs somewhat later than the imported species 

 and the larvsee are green. The same remedies as those used against the im- 

 ported species will apply. 



AFFECTING THE FOLIAGE. 



Fall Web-worm (see Insects affecting the apple). 



INSECTS AFFECTING THE GRAPE. 



AFFECTING THE BOOTS. 



The Grape-vine Phylloxera. (Phylloxera vastatrix.) 



The grape phylloxera is a native of America, where it has worked from time 

 Immemorial on the wild grape. This louse, in common with many other insects, 

 does little injury in its native home. In Europe it is the worst enemy of the 

 grape and here in America it is a serious enemy only to grapes of European 

 origin. 



The presence of phylloxera is made known by small galls on the under side 

 of the leaves, and by somewhat similar galls on the roots. These galls if cut 

 open early in their growth, are found to contain small plant lice, the galls on 

 the roots eventually rotting out with a good portion of the rootlets, finally de- 

 stroying the v.'hole root system and leading to the death of the vine. 



The Insect occurs in four forms; the leaf-inhabiting form, the root-inhabiting 

 form, the winged form and the sexual form. Winged lice appear when the 

 colonies become crowded, and thus provide for the spread of the species and 

 the founding of new colonies. It very often happens that the leaf-inhabiting 

 form is quite numerous while the root-inhabiting form is not in evidence, further- 

 more the reverse is often true. 



