28 



Table 2. Average I insect injury on fruit at harvest in Previous 

 Year IPM, First-Year IPM and Check commercial orchards in 

 Massachusetts, 1982. 



1982 Injury ("a) 



Previous-Year'^ First Year 

 IPM blocks IPM blocks 

 Pests (25 blocks) (11 blocks) 



Tarnished Plant Bug 1.12 



Plum Curculio 0.43 



San Jose Scale 0.84 



European Apple Sawfly 0.87 



Gypsy Moth 0.01 



Apple Maggot Fly 0.01 



Leaf Roller 0.02 



Codling Moth 0.0 



IVhite Apple Leafhopper 0.0 



Green ^ruitworm 0.01 



Sooty Mold fungus 1.00 



Total % injury 4.31 3.81 3.51 



Based on on-tree survey of 600-2,000 fruit per block at harvest (100 

 fruit per tree from each of 2 trees adjacent to each trapping station), 



■^Orchards which have been on an IPM program one or more years. 



Mite populations . 



Table 3 contains results of mite sampling performed in IPM and 

 check commercial orchards in 1982. Relatively high numbers of mites 

 per leaf in IPM orchards probably have more to do with sampling methods 

 than with any differences in control efficacy among blocks. 



In IPM blocks samples were taken on a weekly basis proximal to 

 "hot spots" and were initiated when signs of bronzing or active mites 

 were observed. Samples in Check orchards, on the other hand, were 

 collected at random intervals, often after growers had treated for 

 mites . 



There is an apparent association between higher prey mite numbers 

 and higher predatory mite numbers. However, from a pest management 

 perspective, 1982 was not a good year for biological mite control in 

 Massachusetts. In most IPM blocks the early part of the growing season 

 (through early July) saw few mite problems. Heavy rainshowers apparent- 

 ly washed adult mites off the leaves and cool wet weather was not con- 

 ducive to mite reproduction. Bronzing was mild at this time and trees 

 were growing vigorously. 



In July and August, however, hot dry conditions resulted in rapid 

 mite buildup in many blocks. ERM numbers above treatment level con- 

 tinued in some cases into September. Red mite eggs were observed in 



