Q 

 H 



^10 



30 



20 



10 







MITES 



1986 1968 1990 1992 1994 1996 1996 2000 



WALH 



1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 



1982 1984 1986 1 



1990 1992 1994 1996 1998 2000 



WAA 



1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 



Figure 2. For each principal arthropod pest of fohage in the Conway orchard, the relationship between 

 annual pest incidence and time (from 1986-2000). 



blackberry plants (as well as grape and sumac) within 

 100 yards of the orchard perimeter were removed. This 

 alone proved insufficient to reduce incidence of 

 summer diseases to an acceptable level and was 

 followed by application of two fungicide sprays for 

 the fourth quartile. Finally, increasing yields associated 

 with orchard maturity necessitated less reliance on hand 

 removal of excess fruit as the sole approach to thinning 

 and use, during the third and fourth quartiles, of the 

 chemical thinner carbaryl as an amendment to phosmet 

 in the first insecticide spray. 



The only Conway orchard pest that increased 

 significantly across the two decades of orchard 

 operation was leafminers. The increase coincided with 

 a shift from 100% apple blotch leafminer to 98% 

 spotted tentiform leafminer as the dominant leafminer 

 species in the orchard. Such a shift in leafminer 

 composition occurred during this same time period in 

 several large New England apple orchards, for yet 

 uncertain reasons. The potential impact of this shift 

 on leafminer management remains to be determined. 



In another article in this issue of Fruit Notes, we 



present information on incidence across eight years 

 (1991-1998) of codling moth, lesser appleworm and 

 leafrollers in small blocks (about 1/2 acre) of apple 

 trees m six large commercial orchards, wherein each 

 block was surrounded by odor-baited spheres to control 

 apple maggot and no insecticide was applied after mid- 

 June. Results showed a slight but insignificant 

 tendency toward increase of codling moth and lesser 

 appleworm and a moderate and significant tendency 

 toward increase of leafrollers across the eight years. 

 The slight but insignificant trend toward increasing 

 incidence of lesser appleworm over time in the small 

 blocks of apple trees in commercial orchards matches 

 a similar trend found for lesser appleworm in the 

 Conway orchard. On the other hand, there were slight 

 long-term trends toward decreasing numbers of codling 

 moth and leafrollers in the Conway orchard that were 

 inconsistent with the long-term trends toward 

 increasing numbers of these pests in the small blocks 

 of apple trees in the commercial orchards. Reasons 

 for this inconsistency are unknown but could involve 

 natural ecological processes having a greater influence 



Fruit Notes, Volume 66, 2001 



