486 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



winged males appear and mate with the true females, which thci 

 lay the eggs. 



Control. The aphides may be readily killed by spraying wit) 

 kerosene emulsion, whale-oil soap, 1 pound to 6 gallons of water 

 or tobacco extracts, but the spraying must be done before th 

 foliage becomes badly curled. Ordinarily they may be hel< 

 in check by picking off the curled leaves by hand. 



The Imported Currant-worm * 



' The most destructive insect that attacks the currant," say 

 Professor Lugger, " is the above-named saw-fly, which feed 



FIG. 350. The imported currant-worm (Pteronus ribesii Scop.): a, male anc 

 female saw-flies; b, larvae; c, pupa; d, cocoon; e, eggs all enlarged 

 (After Lugger.) 



indiscriminately on all kinds of currants and gooseberries. The 

 imported species is supposed to have been accidentally introduced 



* Pteronus ribesii Scop. Family Tenthredinidce. See Lugger, Bulletin 

 43, Minn. Agr. Exp. Sta., p. 179; C. L. Marlatt, Bulletin 3, Tech. Series, 

 Div. Ent., p. 61. 



