374 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



water, whale oil-soap, 1 pound to G gallons, or black leaf-tobacco 

 extract, 1 part to 64 of water, will destroy the aphides, but the 

 spraying must be thorough, as the waxy coating serves to pro- 

 tect them. According to Professor Franklin Sherman, any good 

 laundry soap used at the rate of 1 pound dissolved in 3 gallons of 

 water, will destroy the aphides. Where water under pressure is 

 available in a small garden, the aphides may be held in check by 



d 



FIG. 270. The spinach-aphis (Myzus persicce Sulz.): which often becomes 

 a cabbage pest: a, winged adult; b, young nymph; c, older nymph; d, 

 last stage of nymph all greatly enlarged. (After Chittenden, U. S. 

 Dept. Agr.) 



washing them from the plants with a strong stream from a garden 

 hose. Plants infested in the seed-bed may be freed from the 

 aphis by dipping in whale-oil soap solution, 1 part to 8 of water. 



Fortunately for the grower, the cabbage-aphis is usually held 

 in check by numerous parasitic enemies, principally little wasp- 

 like flies of the family Braconida?, and by several species of lady- 

 bird-beetles and syrphus-fly larvae, which will often destroy a 

 colony within a few days. 



