Acknowledgements 



This work was supported principally by a grant 

 to study biological control of apple orchard pests 

 from the Massachusetts Department of Food and 

 Agriculture. We thank the participating growers for 

 their cooperation: Bill Broderick, Bruce Carlson, 

 Dave Chandler, Dave Cheney, Tony Lincoln, Dave 

 Lynch, Harvey and Marvin Peck, Wayne and Jesse 

 Rice, Bill Rose, Tony Rossi, Steve Smedberg, and 

 Maurice Tougas. 



References 



Bostonian, N.J., Dondale, CD., Binns, M.R., and 

 Pitre, D. 1984. Effects of pesticide use on spiders in 

 Quebec apple orchards. Can. Entomol. 116:663-675. 



Dondale, CD, Parent, B., and Pitre, D. 1979. A 6- 

 year study of spiders in a Quebec apple orchard. 

 Can. Entomol. 111:377-380. 



McCaffrey, J.P. and R.L Horsburgh. 1980. The 

 spider fauna of apple trees in Central Virginia. 

 Environ. Entomol. 9:247-252. 



Nyfeler, M. and Berry, G. 1987. Spiders in natural 

 pest control: a review. J. Applied Entomol. 103:321- 

 339. 



fnm. IVaai. J. J. IBM Tkt Anrnwi ftiwt 



Massachusetts Apple IPM Program 

 Observations in 1990 



Kathleen P. Leahy and William M. Coli 



Department of Entomology, University of Massachusetts 



Daniel R. Cooley 



Department of Plant Pathology, University of Massachusetts 



Insect and Disease Situation 



Scab: The most notable form of injury at harvest 

 was apple scab. Growers who timed their sprays 

 well and had a good understanding of the use of 

 sterol-inhibiting (SI) fungicides had little problem 

 with scab; however, growers who "played games" 

 with the Sis had serious problems. Clearly, the pres- 

 sure was intense during part of the primary scab 

 season, resulting in high levels of injury where trees 

 were not protected. Interestingly, one grower used 



3 SI + protectant applications beginning at bloom 

 and his fruit had no injury at harvest. 



Apple Maggot Fly: Generally, insect problems 

 were insignificant this year, but apple maggot fly 

 was present in fairly large numbers through most of 

 August and September, resulting in the need for 2 to 



4 half-rate insecticide applications. Injury from 

 apple maggot fly was noted in some low-spray and 



no-spray blocks. 



Leafminer: An extraordinarily large emergence of 

 leafminer adults occurred in many orchards this 

 spring; however, it resulted in little or no egglaying 

 in the first generation. In the few cases where mines 

 were present in substantial numbers, they seemed to 

 be concentrated on the same age cluster leaf, and 

 were extremely localized within the orchard. Per- 

 haps the high winds during the time when adults 

 were flying prevented significant egglaying. Popu- 

 lations did build up again over the course of the 

 season, but did not reach damaging levels in the 

 second or third generation in most orchards. 



Tarnished Plant Bug, European Apple Sawfly, 

 Plum Curculio: These early-season fruit-injuring 

 insects were at very low levels, and injury at harvest 

 was not significant. Many growers were able elimi- 

 nate their pre-bloom insecticide application and also 



14 



Fruit Notes, Winter, 1991 



