-6- 



10. The use of the airplane make possible the convenient extension of the prun- 

 ing season well Into the pre-bloom time because the brush removal problem 

 to make room for ground-operated spray and dust equipment does not exist. 



— C. Lyman Calahan 



I I I I I I I I I I I I I I I I 



THE APHIDS ON APPLE - III 



Green Apple Aphid 



This Is the most abundant aphid on apple. It Infests terminals, water 

 sprouts and young trees throughout the season. Winged, migratory forms appear 

 In every generation and relnfestatlon and build-up to damaging numbers can be 

 very rapid. 



The apple aphid Infests pear, hawthorn, crabapple, quince, and other 

 members of the rose family. Migration between hosts occurs throughout the 

 season. 



The "Insurance" programs described for rosy apple aphid In December "Fruit 

 Notes" will kill the green apple aphlds on treated trees. They do not "Insure" 

 against relnfestatlon from outside sources. 



Baldwin, Red and Golden Delicious, Cortland, Gravensteln, and Greening 

 are most seriously Infested but Mcintosh often serves as an Important source 

 for migrating aphlds. 



Relatively cool weather with an abundance of moisture favors succulence 

 and thus the apple aphid. The relative abundance of syrphld fly, lace wing 

 fly, and lady beetle predators is another very important factor governing the 

 extent of apple aphid build-up. Unfortunately, many present day insecticides 

 kill these predators and parasites. 



Three types of Injury are caused by the green apple aphid, (1) leaves 

 of terminals are stunted and distorted, terminal gro\^h is shortened and even 

 crooked, (2) fruit and leaves become smutted frcsa a growth of sooty mold 

 in the honey dew secretion, (3) in severe infestations aphlds may feed on the 

 fruit causing gnarllng or dimpling. 



Regardless of the program followed earlier you need to watch for green 

 apple aphid build-up in early and mid-summer when control can be a part of your 

 regular summer schedule. 



More About the Aphid Itself 



During late September and October wingless, egg laying females and wingless 

 males were produced and after mating, overwintering eggs were deposited. 



The oval, shiny, black eggs cannot be dlstinqulshed from those of rosy and 

 grain aphlds. However, they are most abundant on water sprouts and the vigorous 

 terminals of both old and young trees. 



