L.XAJ3t3lJ?J(JAiiUJN AND UKSCKiFTiUJN UH LUMMUJN liNbiLCTb 



147 



on roots, twigs and leaves. No migration. Of no economic importance 

 in Ontario (Fig. 98). 



Mealy Plum Louse {Hyalopterus arundinis Fab.). — Has long narrow 

 light green body with three longitudinal stripes; covered with a mealy 

 powder; honey-tubes short and thick; winged females migrate in June 

 to grasses and cat-tail and return in autumn. 



Variable Currant Aphis {Aphis varians Patch). — Infests currants, 

 gooseberries and flowering currants, causing curling of the leaves. 

 The winged summer forms migrate to some unknown host, and return 



Fig. 98. — Black peach aphis (winged female). {After Quainlance.) 



in the fall. The eggs are deposited on the twigs. The stem-mother 

 is purplish-green with white honey-tubes. The winged form has a 

 black head and body, with a dark green abdomen marked with black, 

 while the wingless form is dark green, tan or dark brown. 



Green Gooseberry Aphis {Aphis sanborni Patch) .^ — Green; honey- 

 tubes white. 



Grape Phylloxera {Phylloxera vitifolice Fitch = vastatrix Planchoa). 

 —Four forms are recognized: (i) wingless leaf-gall form; (2) wingless 

 root form; (3) winged form; (4) sexual form. 



I. Adult leaf -gall form is a wingless female, plump, orange-yellow. 

 Fills gall with many yellow eggs which hatch in 3 days into females. 

 Several generations during summer. The feeding puncture stimulates 

 the growth of the leaf tissue so that a hollow gall is produced, opening 

 on the upper surface. 



