Tabic 1. Mean numbers of I . I>yn and lluropean red mites (ERM) per leaf m late Aiif;iisi and pesticides 

 used in third-level IPM blocks in ei^;lii commercial apple orchards in Massachusetts m ]'-)^)H where T. 

 pyri were released in May of 1997. 



Mean n(j. per leaf 



^- py' 



Orchard 



1997 1998 



ERM 

 1998 



Miticide used 



No. EBDC" 



fungicide 

 applications 



1997 



1998 



1997 



1998 



No. 



insecticide* ' ' 



applications 



1997 



1998 



A' 



B 



C 



D 



E 



F 



G 



H 



1.02 

 0.92 

 0.08 

 0.67 

 1.09 

 0.03 

 1.41 

 0.38 



1.93 

 1.74 

 1.03 

 0.41 

 0.33 

 0.16 

 0.13 

 0.09 



0.03 

 3.92 

 0.09 

 0.05 

 0.00 

 0.31 

 0.01 

 0.03 



Oil 



Oil 



Oil 



Savey 



Savey 



Agri-Mek 



Savey 

 Pyramite 



Oil 

 Savey 



Oil 

 Agri-Mek 

 Agri-Mek 

 Pyramite 

 Agri-Mek 

 Agri-Mek 





 3 

 

 

 

 

 

 



Averaged across all three sizes of trees sampled. 



Application through mid-June, none thereafter. 



Includes only insecticides known to be moderately or very harmful to T. pyri: synthetic 



pyrethroids, oxamyl, methomyl and chlorpyrifos. 



* » * 



We are encouraged by these findings and plan Acknowledgments 

 to continue our study of the extent of establish- 

 ment and spread of T. pyri in these same third- 

 level IPM blocks in 1999. At the same time, we 

 find it sobering that the rate of spread of T. pyri 

 into non-release trees is apparently quite modest 

 and that certain pesticides that were believed to be 

 no more than moderately harmful to T. pyri (e.g. 

 Agri-Mek) may in fact be very harmful. 



We are grateful to the eight growers partici- 

 pating in this experiment and who made special 

 effort to apply pesticide selectively to third-level 

 IPM blocks: Bill Broderick, Dave Chandler, Dana 

 Clark, Dave Shearer, Joe Sincuk, Tim Smith, and 

 Mo Tougas. This work was supported by State/ 

 Federal IPM funds. 



kK k9^ k9^ Kf^ %t^ 



^c ^c ^c ^c ^c 



Fruit Notes, Volume 6A (Number 1), Winter, 1999 



15 



