15. 



Specifically, TPB remained a highly damaging fruit pest in 

 Massacliusetts commercial orchards (Table 1) , as was the case 

 in 1978 and 1979. Tarnished plant bug injury in IPM and Check 

 blocks was identical inspite of higher pest pressure in IPM blocks 

 (7.4 TPB adults per trap in IPM vs. 6.0 adults per trap in Checks), 

 Continuing our attempts to develop a TPB grading index, we found 

 that bl% of TPB injured fruit would grade through as US Fancy, 

 while 351 would grade US No. 1 and 6% would be culled. This high 

 percentage of very minor TPB injury may relate to the rapid, early 

 buildup in TPB populations before pink, when feeding results pri- 

 marily in bud abscission rather than serious scars resulting in 

 downgrading of fruit value. 



San Jose scale continues to be a serious pest of apples in 

 Massachusetts, although injury in IPM blocks was only SC^ as 

 great as in the Checks. The high average injury due to scale in 

 partial cooperator blocks resulted from one grower's failure to 

 treat for scale with prebloom oil, despite advice to do so. The 

 result was scale injury on 55% of fruit sampled. 



Plum curculio injury was substantially higher in all blocks 

 in 1980 than in 1979 even though some growers applied as many 

 as 4 insecticide sprays to control this pest. Injury in IPM 

 blocks was 271 greater than in Checks, due primarily to 9.4% 

 PC injury in one block (the grower was unable to apply a recom- 

 mended spray over the May 24-26 weekend, when PC activity was 

 high, because beehives were still in the orchard). 



Trap captures of AMF adults were higher than in 1979, as was 

 the injury from this pest in both IPM and Check blocks. In 

 one IPM block, no AMF adults were captured until August 15, and 

 CM captures were also low. As a result no insecticide sprays 

 were applied between June 9 and August 15, and no AMF sprays 

 were needed thereafter. Our harvest injury survey found no injury 

 from either of these pests in this block, pointing out the poten- 

 tial savings to growers that may result from use of sticky sphere 

 and pheromone traps for AMF and CM, respectively. 



No spray applications were required in any IPM blocks for 

 CM, LR, or GFW, and combined injury from these pests was slightly 

 lower in IPM than Check blocks. Injury from WAA, WAL and SM was 

 substantially higher in IPM than Check blocks, due principally 

 to high (6.91) WAL injury in one IPM block. Inasmuch as speckling 

 from WAL excrement is superficial and would probably be removed 

 by normal post harvest handling, it is doubtful that this "injury" 

 is of economic importance. 



Mite populations 



Populations of harmful plant feeding mites were virtually id- 

 entical in IPM and Check blocks in 1980. European red mite and 

 two spotted mite numbers generally peaked in late July and early 

 August, in response to hot dry weather, and may have caused some 

 fruit drop at populations lower than would normally be expected 

 to cause drop. Perhaps mite feeding combined with the stress of 



