odor-baited red sphere traps), and (4) no release of T. 

 pyri and organophosphate insecticide applied during 

 July and August to control apple maggot. For the first 

 and second treatments, T. pyri were released at bloom 

 at the rate of about 100-200 individuals per tree on 

 two trees in the fourth row of each plot, one tree to the 

 right and one to the left of the center tree of the plot. 

 Releases were made by wrapping a burlap band that 

 contained T. pyri around the trunk of a release tree. In 

 autumn of 1999, such bands had been placed around 

 trunks of apple trees at Geneva, NY to collect T. pyri 

 seeking overwintering sites. 



In 2000, we sampled 25 leaves per tree on each of 

 two trees in rows 1, 4 and 7 in each plot. We did this 

 twice during July and twice during August. One of the 

 sampled trees was immediately to the right and the other 

 immediately to the left of the center tree of the row 

 (for rov\ 4, these were the same trees in which T. pyri 

 were released). For 2001, 2002 and 2003, we no longer 

 segregated samples according to plot and sampled five 

 leaves on each often trees (50 in all) on each of rows 

 1, 4 and 7 in each block. We did this twice in 2001 

 (once in July and once in August), once in 2002 (in 

 July) and twice in 2003 (once in July and once in 

 August). 



In 2000, in four of the blocks we planted 20 

 seedling trees of American hazel in hedgerows opposite 

 and about 5 meters away from plots in which T. pyri 

 were released. Our intent was to sample leaves from 

 these seedlings for abundance of predatory mites as 

 soon as the seedlings achie\ ed reasonable growth 

 (reached 1 meter height). Hence, in 2002 and 2003, 

 we sampled five leaves from each often American hazel 

 seedlings (50 leaves in all) once during August in each 

 of the four blocks. 



All sampled leaves were sent by overnight mail to 

 Geneva. New York for the identification and counting 

 of pest and predatory mites. 



From 2000-2003, none of the sampled plots 

 received pyrethroid or carbamate insecticide (except 

 carban. 1 as thinner), none received EBDC fungicide 

 after mid-June, and none received miticide (except 

 prebloom oil). The only exception was orchard F, which 

 received a spot-treatment of Acramite in August of 2003 

 against European red mite. 



Results 



With respect to our first question, data for 2000 

 presented in Figure 1 show that addition of cattail 

 pollen had no detectable effect on the buildup of T. 

 pyri in trees in which these predators were released. 

 Peak populations of T. pyri in 2000 were just as great 

 in trees not receiving cattail pollen as in those that did 

 receive pollen, and were roughly twice as great (on 

 sampled center trees in row 4) in plots where T. pyri 

 were released as in plots where no T. pyri were released. 

 Conversely, peak populations of European red mites 

 on sampled trees averaged about twice as great in plots 

 where no T. pyri were released and which received 

 insecticide during July and August as in plots where T. 

 pyri were released and received no insecticide after 

 mid-June. Peak populations of A. fallacis averaged 

 roughK the same in all plots. For each of the four plot 

 types. A- fallacis was less abundant than T. pyri. 



In regard to our second question, there was no 

 statistical evidence that spread of T. pyri differed among 

 the rows of trees, although data for 2001 shown in Fig. 

 2 hint that T. pyri released in 2000 on trees in row 4 

 may ha\ e spread faster to trees in row 7 than to trees 



2 



S 1.5 



TP 



Figure 1. For 2000, peak abundance of 7! /J'>T/(TP),/4./a//acK (AF) and European red mites (ERM) in two trees 

 in row 4 of each of four plots in each of 12 orchard blocks: trees in which TP were released and cattail pollen was 

 added (TPP), trees in which TP were released but no pollen was added (TPNP), trees in which no TP were 

 released, no pollen was added and apple maggot was controlled by baited red sphere traps (NTP) and same as 

 preceding except apple maggot was controlled by grower-applied insecticide (GC). 



Fruit Notes, Volume 68, Spring, Summer, & Fall, 2003 



