Third-level, Low Tree Dens ity 



.1-- 



12-Aug 



[Z: 



1997 1998 



-1999 



Third-level. High Tree Den sity 



1997 1998 



-1999 



Firsf-level, Low Tree Den sity 



12-Aug 



1997 1998 



-1999 



First-level, Medium Tree Density 





12-Aug 



2-Sep 



1997 1998 



Figure 9. In 1997, 1998, and 1999, abundance to European red mites (ERM)on center trees of outer rows of third- 

 level IPM blocks (in which T. pyri were released on center trees in mid-May 1997) and center trees of outer rows 

 of first-level IPM blocks (in which no releases of T. pyri were made). 



Fruit Notes, Volume 65, 2000 



15 



