8 - 



Tarnished plant bug . Once again, TPB dimples and cat-facing repre- 

 sented the largest single amount of on-tree insect injury in commercial 

 orchards in Massachusetts. This year's average injury is up compared to 

 that of the previous 7 years (Table l). Cumulative TPB captured on white 

 visual traps were very high early in the growing season, ranging from 

 2.5/trap to 6.2/trap at late tight cluster ('4/26) in extension-monitored, 

 commercial blocl<s. At the Horticultural Research Center (Belchertown) cumu- 

 lative captures in the unsprayed block were 3.1/trap at tight cluster 

 (^/23) . Captures above 2.4/trap at tight cluster exceed the economic 

 threshold level (ETL), and indicate the need for an insecticide pre-bloom. 

 Very few captures were recorded after early pink so tnat optimal timing o' 

 TPB sprays was at tight cluster in 1985- Delays in af plication may account 

 for the higher than average TPB injury seen this year. 



Plum Curcul io . Relative to tree development, PC A/ere "early" in I985, 

 with the first adult detected on Orchard Hill on May I (late pink to early 

 bloom on Mcintosh). PC appeared in commercial orcha ds during bloom e'en 

 though fruit were too small to allow egglaying. Egglaying occurred ove a 

 relatively short period of time, beginning at petal fall. Additional PC 

 activity was seen in late June-early July with block edges and known hot 

 spots sustaining some injury at that time. Overall, however, PC injury was 

 lower than average. 



A jple Maggot Fly . In I985, AMF trap caputures in comnercial blocks 

 were comparable to those in the previous years, with peak fly activity 

 coming, as usual, in August in Dr. Prokopy's unsprayed block in Conway, MA. 

 In extension-monitored, commercial blocks, trap captures continued to har- 

 vest, with peak captures in September rather than in August. This could be 

 ascribed to lessened pesticide pressure, allowing greater fly survival, but 

 captures in the unsprayed block also increased noticeably in September. 



Apple Leafminers . Most growers v/ere able to control LM quite well in 

 1985, using pyrethroids or carbamate insecticides. However, two aspects of 

 the future of control programs for LM were discussed at the annual October 

 meeting of Northeastern US and Canadian tree fruit researchers. One area of 

 apparent consensus was that pyrethroids, even if just used pre-bloom, are 

 resulting in earlier and more severe mite outbreaks, which many growers are 

 having difficulty controlling due to miticide resistance. The other was the 

 finding by Canadian entomologist Dr. Dave Pree that LM, long known to be 

 resistant to organophosphate and pyrethroid insecticides, have also deve- 

 loped a measure of resistance to the carbamate insecticide methomyl 

 (Lannate^, Nudrin"), even when this pesticide had been applied only once pei 

 season for three years. However, we have no indication that such resistance 

 has developed in Massachusetts as yet. 



Red visual traps for LM monitoring and spray decision-making continued 

 to show great promise in tests performed by Extension and by New England 

 Fruit Consultants. In all of the five Extension blocks, traps indicated 

 whether or not sprays were required for LM (three "yes", two "no"). Traps 

 positioned close to the ground and adjacent to tree trunks caught greater 

 numbers of overwintering generation moths than traps at head height, con- 

 firming earlier work of Tom Green. Beginning the week of May 13» head 



