Table A. Characteristics of Redcort and Cortland fruit after 17 weeks of 

 CA storage followed by 14 weeks of air storage. 



*Within columns, means not followed by the same letter are significantly 

 different at the S% level. 



PICKING UP APPLE DROPS TO PREVENT BUILDUP OF 

 APPLE MAGGOT FLIES IN "ORGANIC" ORCHARDS 



Ronald J. Prokopy 

 Department of Entomology 

 University of Massachusetts 



The apple maggot has been a key pest in eastern and midwestern apple 

 orchards ever since it expanded its host range from hawthorn (its native 

 host) onto apple sometime mid 19th century. Before the advent of inorganic 

 pesticides such as calcium arsenate and lead arsenate in the early part of 

 the 20th century, the only effective method of controlling the apple maggot 

 was to pick up dropped fruit from beneath apple trees to prevent the larvae 

 from forming pupae. So long as drops were picked up on a frequent schedule, 

 this practice precluded pupal buildup beneath orchard trees and thereby pre- 

 vented wi thi n-orchard fly emergence the next summer. It could not affect 

 immigration of flies from sources outside an orchard, however. 



Nowadays, with so many effective pesticides available to control the 

 apple maggot, probably few, if any, commercial apple growers in eastern or 

 midwestern regions bother with picking up maggot- i nfested drops. The 

 situation is very different in California, however. In an earlier article 

 (Fruit Notes 49(2) : 16-18) , I gave a brief account of how the apple maggot 

 fly was first detected in California in August of 1983 and how it has 

 created a state of alarm among many apple growers there. Indeed, twice 

 within the past year, 1 have been called upon to file legal declarations on 

 various aspects of apple maggot management. One of the declarations was in 

 behalf of "California Organic Apple Growers" and supported a proposed 

 program of apple maggot control that did not involve use of pesticides. If 

 such a program were to prove effective, an organic apple grower would not 

 then be required by law to have his orchard sprayed with pesticide by the 

 State to control maggot. If not, then the grower would have to submit his 



