date had any substantial impact on ERM abundance. 

 Mines from ABLM likewise were more abundant on 

 fruit cluster leaves than on non-cluster leaves. In this 

 case, the fewest ABLM mines on both cluster and non- 

 cluster leaves were found on trees pruned on July 1. 

 Perhaps pruning on this date eliminated leaves that 

 otherwise would have been utilzed by second genera- 

 tion ABLM ovipositing at that time. The lowest WAA 

 populations were found on trees pruned on August 1 

 and August 15. Summer pruning on any date did not 

 appear to lead to buildup of either ERM or ABLM 

 compared with populations on non-pruned trees, al- 

 tough WAA on trees pruned July 15 and September 1 

 were slightly greater than populations on non-pruned 



trees. 



In Experiment 2 (Table 2), there were no apparent 

 differences in the numbers of ERM, WAA, or ABLM 

 mines among treatments. However, there did tend to 

 be more ERM and more ABLM mines on cluster leaves 

 than on non-cluster leaves. 



These data are preliminary and should be com- 

 bined with results on fruit production to make sound 

 decisions about summer pruning. While further re- 

 search is needed to determine the influence of summer 

 pruning on pest and predator populations throughout 

 the summer, the results presented here do not suggest 

 that summer pruning has a major impact on foliar pest 

 populations. 



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Fruit Notes, Spring, 1989 



