Comparative Level of Establishment 

 of Released Typhlodromus pyri 

 Predatory Mites in First-level and 

 Second-level IPM Apple Orchard Blocks 



Ronald Prokopy, Starker Wright, and Jennifer Mason 

 Department of Entomology, University of Massachusetts 



Jan Nyrop, Karen Wentworth, and Carol Herring 



Cornell University, NY Agricultural Experiment Station, Geneva 



As described in the Spring 1994 issue of 

 Fruit Notes, Amblyseius fallacis is the most 

 commonly occurring predatory mite in Massa- 

 chusetts apple orchards. Unlike orchards in 

 many other states, few Massachusetts apple 

 orchards harbor detectable levels of 

 Typhlodromus pyri predatory mites. Previous 

 studies in Massachusetts have shown that A. 

 fallacis rarely builds to levels capable of 

 providing effective control of European red 

 mites until mid-July at the eairliest, and often 

 not until August. In contrast, studies in New 

 York have shown that T. pyri, where 

 established, can provide effective biocontrol of 

 European red mites beginning as early as May. 



In 1995, we released T. pyri into two first- 

 level IPM and two second-level IPM block of 

 apple trees in each of six commercial apple 

 orchards in Massachusetts. Here, we report on 

 the abundance of T. pyri in samples taken in 

 September of 1995 and 1996 in each of these 

 blocks as well as in adjacent first- and second- 

 level IPM blocks where no T. pyri were 

 released. 



Materials & Methods 



All six orchards were located in west-central 

 or east-central Massachusetts. Each block was 

 comprised of about 60 trees of the cultivars 



Mcintosh, Empire, or Cortland (on M.7 or M.26 

 rootstock). First-level IPM blocks received 

 pesticide sprays applied by growers timed 

 according to pest and weather-monitoring 

 activities that the growers themselves carried 

 out. Second-level IPM blocks were treated 

 identically to first-level blocks through early 

 June. Thereaft;er, no pesticide of any type was 

 applied to second-level blocks. Instead, a 

 combination of behavioral, cultural, and 

 biological control techniques was used. 



In 1995, blossom clusters harboring T. pyri 

 were picked fi-om an orchard at the New York 

 State Agricultural Experiment Station at 

 Geneva, transported in a cooler by automobile 

 to Massachusetts on the same day when picked, 

 and placed the following day in targeted blocks. 

 This involved using twist-ties to attach 50 

 blossom clusters to the central tree of each 

 target block. 



In September of 1995 and 1996, 25 leaves 

 were picked at random from the central tree 

 (that is, the release tree) in each block receiving 

 T. pyri and 25 leaves fi-om each of four trees 

 nearest the central tree. A similar protocol was 

 followed for sampling central and adjacent 

 trees in first- and second-level blocks not 

 receiving released T. pyri. Sample leaves were 

 cooled and shipped to Geneva, New York for 

 identification and counting of predatory mites. 



Fruit Notes, volume 62 (Number 2), Spring, 1997 



