Third-level, Low Tree Density 



12-AU9 



1997 1998 



-1999 



Third-level, Medium Tree Density 



12-Aug 



■ - 1997 1998 



-1999 



Third-level, High Tree Density 



2-Sep 



-1997 



■1998 



-1999 



First-level, Low Tree Den sity 



12-Aug 



-1997 1998 



-1999 



First-level, Medium Tree Density 



lU 4 



1997 



— 1998 



-1999 



First-level, High Tree Den sity 



12-Auo 



L 



1997 1998 



-1999 



'] 



Figure 7. In 1997, 1998, and 1999, abundance to European red mites (ERM) on center trees of third-level 1PM 

 blocks (in which T. pyri were released on center trees in ntid-May 1997) and center trees of first-level 1PM blocks 

 (in which no releases of T. pyri were made). 



Fruit Notes. Volume 63. 2000 



13 



