ORCHARD INSECTS OF THE PACIFIC NORTHWEST 



23 



LIFE HISTORY 



This aphid passes the winter in the egg stage, in the same manner as 

 the rosy apple aphid, although the eggs are more likely to occur on 

 water sprouts. The eggs hatch at about the same time as do those of 

 the rosy apple aphid, and there may be from 9 to 17 generations in a 

 year. Young and adults are green, with black legs, and often with 

 yellowish heads. Some of the adults are winged, and these migrate to 

 other apple trees, thus spreading the infestation during the season. 

 Green eggs are deposited in the fall, and later become glossy black. 



CONTROL 



The control measures recommended for the rosy apple aphid are also 

 effective for this species. Since it remains on the trees throughout the 

 season and migrates from tree to tree, additional sprays may be nec- 

 essary, particularly on young trees or on nursery stock. Nicotine 



Figure 25.— Proper stage at which 

 to spray for aphids. 



Figure 



—Green apple aphids on 

 apple foliage. 



sulphate (40 percent nicotine), to winch is added 2 or 3 pounds of soap 

 in solution or 1 pound of casein spreader to every 100 gallons of spray, 

 is very effective if applied thoroughly in order to reach the aphids in 

 the curled leaves. In hot weather, when the temperature is above 80° 

 F., the quantity of nicotine sulphate may be reduced to one half pint 

 to 100 gallons, as nicotine is more effective in hot weather than in cool 

 weather. If bearing apple trees are to be sprayed, this application 

 may be combined very effectively with a summer oil emulsion and used 

 in place of one of the regular applications of lead arsenate for the 

 codling moth. 



WOOLLY APPLE APHID 



The woolly apple aphid {Eriosoma lanigerum Hausm.) attacks the 

 roots as well as the upper parts of the trees. Aboveground it is found 

 chiefly on the trunks, limbs, and twigs, in wounds caused by pruning 

 or cultivating implements, and wherever the bark is tender (fig. 27). 

 Twigs become somewhat swelled and knotted as a result of its attacks. 

 The aphids are occasionally found on the fruit stems and in the calyx 

 ends of apples. Injury to the roots is not very important in the arid, 

 sandy areas of the Northwest, and in those areas it is more or less 



