426 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



control of this species. Mr. Lowe states that a few females may 

 be found on the foliage throughout the summer. In late October 

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

 lay the eggs. 



Control. The aphids may be readily killed by spraying with 

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

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



FIG. 359. The imported currant-worm (Pteronus ribesii Scop.): a, male and 

 female saw-flies; 6, larvae; c, pupa; d, cocoon; e, eggs all enlarged. (After 

 Lugger.) 



foliage becomes badly curled. Ordinarily they may be held 

 in check by picking off the curled leaves by hand. 



The Imported Currant-worm * 



" The most destructive insect that attacks the currant," says 

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



* Pteronus ribeeii Scpp. Family Tenthredinidce. See Lugger, Bulletin 

 43 Minn. Exp. Agr. Sta., 179; C. L Marlatt, Bulletin 3, T ch. Series, 

 Div Ent., p. 61. 



