Table 5. Seasonal average populations of pest mites and mite predators in second-level 

 and first-level IPM blocks.* 



Mite presence (% of leaves) 



* Means in each couplet in each column followed by a different letter are significantly 

 different at odds of 19:1. ERM = European red mite TSM = Two-spotted mite; Af = 

 Amblyseius fallacis; YM = yellow mite. 



did not experience significant mite populations until late 

 summer. Mite populations in second-level blocks were 

 similar to those in first-level blocks (Table 5). A program 

 of double dormant oil applications in the spring was highly 

 effective in suppressing early mite populations, even in 

 cases where overwintering mite egg numbers were high. In 

 contrast to pest mites, phytoseiid mite predators were found 

 at 5 times the levels of 1993 (Table 5). The slow growth of 

 pest mites allowed for good late season biocontrol, as pest 

 mite levels did not peak until predators were present. 

 Amblyseius fallacis was at statistically similar levels in 

 first-level and second-level blocks, suggesting that the 

 presence of mite predators was not specific to blocks that 

 received no insecticide after early June. Yellow mites were 

 present in slightly higher numbers in second-level than in 

 first-level blocks, but the difference was not statistically 

 significant (Table 5). 



Second-level blocks received slightly less dormant oil 

 and summer oil treatments than first-level blocks, and 

 received no miticides other than oil (Table 1 ). 



Leafliopper populations of all types were abundant in 

 1994. WALH numbers were slightly higher in second-level 

 than in first-level blocks. One second-level block required 

 one summer insecticide application against WALH. PLH 

 proved more of a problem in 1994 than in 1993, and was 

 found in higher levels in second-level than in first-leve! 

 blocks. Rose leafhopper was significantly higher in second- 

 level than in first-level blocks. In one second-level block 

 requiring a summer insecticide treatment against RLH, we 



suggested an application of Omite™^ as an alternative to 

 harsher chemicals. The results were acceptable, although 

 not exceptional. While RLH has not been a problem in all 

 second-level blocks, in those blocks surrounded by multi- 

 fiora rosebushes we have found it to be a consistent concern 

 (Table 6). 



Second- and third-generation leafminer populations 

 were higher in 1994 than in 1993 and were similar in first- 

 and second-level blocks (Table 6). Continuing research on 

 ABLM parasitism rates in first-level and second-level 

 blocks again has shown a higher rate of parasitism of 

 second-generation ABLM larvae in second-level blocks (36 

 vs. 20%). We remain hopeful that parasitism can be proven 

 a successful means of ABLM control in a low-spray pro- 

 gram. 



Green apple aphid populations were higher in 1994 

 than in 1993, as were levels of monitored aphid predators 

 (Table 6). We continue to be content with predator control 

 of GAA. Woolly apple aphid populations on watersprouts 

 were at lower levels than in 1993, and were present in 

 similar numbers in both types of blocks (Table 6). 



Foliar Pests and Beneficial Natural Enemies: 

 Transitional Second-level IPM 



Seasonal averages of mite populations were low in both 

 first- and second-level 1PM blocks (Table 5). One second- 

 level block with a high overwintering ERM egg count and 

 only one dormant oil application had very high niitc num- 



Fruit Notes, Winter, 1995 



