13 



captures occurred in September in commercial blocks and in Dr. Prokopy's 

 orchard. 



Table 1. Percent insect-injured fruit in on-tree surveys of 53 commercial 

 blocks, 1986, compared to orchard harvest injury averages from 1978-1985. 



Insect pest 



Percent injury^ 



1986 



1978-1985 



Tarnished plant bug 

 European apple sawfly 

 Plum curculio 

 San Jose scale 

 Leafrollers 

 Green fruitworms 

 Apple maggot fly 

 Other 



0.83 

 0.01 

 0.75 

 0.11 

 0.02 

 0.03 

 0.05 

 0.02 



1.74 

 0.40 

 0.51 

 0.74 

 0.03 

 0.08 

 0.06 

 0.01 



^Data provided by New England Fruit Consultants. Sample consisted of 50 fruit 

 per tree on 6 to 16 trees per block, depending on block size. 



Apple leafminers - Sticky, red, visual traps again were very useful in 

 predicting potential LM problems prior to bloom. Traps in 3 of 6 blocks 

 indicated the need to treat, later borne out by counts of sap-feeding mines. In 

 2 other blocks, overwintering generation moth captures remained just below the 

 provisional action threshold (12 moths per trap), and first and second 

 generation mines likewise never exceeded the economic injury level. In one of 

 these blocks (which also sustained high levels of white apple leafhopper injury 

 and received no Alar®) we noted a higher level of pre-harvest drop than was 

 seen in other monitored sites. 



White apple leafhopper - White apple leafhopper was again a problem at 

 many sites in 1986, especially where l^'- generation activity was not noted and 

 controlled, or where only organophosphate insecticides were used against the 

 OP-resistant leafhoppers. A few blocks experienced serious, late-season WAL 

 buildup. Also, see later section on potato leafhopper. 



Mites - In most orchards mite numbers were very low this year, possibly 

 due to frequent, heavy rains throughout the summer. A. fallacis predator 

 numbers were very high in all locations compared to recent years, and seemed to 

 be thriving despite the shortage of red mite adults. 



Disease Situation 



The 1986 season was characterized by extreme disease pressure largely 

 caused by prolonged wet weather and low temperatures. The major efforts of the 

 program were to monitor Venturia inaequalis ascospore maturity from April 



