More trials of this sampling method are 

 needed, especially to test regions outside the 

 Shenandoah Valley. This study showed that 

 presence of migrating nymphs indicates trees 

 that are highly likely to have root-feeding 

 aphids. Further trials will enable a more quan- 

 titative prediction using the number of nymphs 

 trapped and determination of a treatment 

 threshold number of trees infested per acre. 

 Cooperators are currently being sought in the U. 

 S. and Canada to help refine this sampling 

 method. 



Acknowledgements 



I thank Dr. S. S. Miller, USDA, ARS, Appa- 

 lachian Fruit Research Station, for his coopera- 

 tion in the use of his orchard; J. J. Schmitt and 



C. Cornell for their hard work in collecting data; 

 and J. J. Schmitt, G. J. Puterka, S. S. Miller, B. 



D. Horton (Appalachian Fruit Research Sta- 

 tion), and H. W. Hogmire (West Virginia Univer- 



sity) for comments on an earUer draft of this 

 paper. 



References 



Brown, M.W., J.J. Jaeger, A.E. Pye, and J.J. 

 Schmitt. 1992. Control of edaphic populations 

 of woolly apple aphid using entomopathogenic 

 nematodes and a systemic aphicide. J. Entomol. 

 Sci. 27:224-232. 



Brown, M.W. and J.J. Schmitt. 1990. Growth 

 reduction in nonbearing apple trees by woolly 

 apple aphids (Homoptera: Aphididae) on roots. 

 J. Econ. Entomol. 83:1526-1530. 



Brown, M.W., J.J. Schmitt, S. Ranger, and H.W. 

 Hogmire. In. Prep. Yield reduction in apple by 

 edaphic woolly apple aphid populations. J. 

 Econ. Entomol. (in preparation). 



Hoyt, S.C. and H.F. Madsen. 1960. Dispersal 

 behavior of the first ins tar nymphs of the woolly 

 apple aphid. Hilgardia 30:267-299. 



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Fruit Notes, Fall, 1993 



