-16- 



In addition, 7 commercial check orchards were monitored for 

 presence o£ aphids and mites and their predators 2-3 times during 

 the season. An on-tree survey of insect and disease injury was 

 performed in these check orchards as well as an analysis of spray 

 usage. 



Grower Financial Support and Cooperation with IPM Specialist Advise - 

 ment - Participating IPM growers paid $16-20/A (depending on total 

 acreage scouted) for insect scouting and advisement in 1981. The 

 charge for disease scouting and advisement was $100 per orchard. 

 Total grower contribution to the IPM program was $8,500 (up from 

 $4,500 inl980) . This was used to pay scout salaries. 



The degree of grower cooperation with IPM specialist recommen- 

 dations was quite high in 1981, averaging 89% cooperation (range 

 651 - 100%) compared to 78% cooperation in 1980. This indicates 

 increasing willingness of IPM growers to (a) rely on predators when 

 possible, (b) to better synchronize sprays with vulnerable stages 

 in pest cycles, (c) to use reduced rates of pesticides, and (d) to 

 withhold sprays entirely should pest numbers be below economic 

 threshold levels. 



Sampling Methods - We have discussed our monitoring techniques in 

 previous issues of Fruit Notes : 44(1), 44(6) and 45(6). With few 

 changes, we employed these same methods in 1981 with the principal 

 changes being: more extensive use of San Jose Scale (SJS) pheromone 

 traps than in 1980, field testing of a visual trap for monitoring 

 Spotted Tentiform Leafminer (STLM) , and mite brushing of leaf samples 

 taken proximal to "hot spots" rather than at random locations in 

 blocks . 



Results 



New or Unusual Outbreaks - The Gypsy Moth (GM) was a problem at 

 numerous sites in 1981. Early instar larvae "ballooning in" were 

 controlled well by pink sprays of endosulfan (Thiodan) or azinphos- 

 methyl (Guthion) . In cases where insecticides were not applied at 

 pink, petal fall sprays provided excellent control, but in some cases 

 not before foliage and fruit were fed on extensively. Later instars 

 were also troublesome, as the large larvae migrated from defoliated 

 hardwood stands into adjacent orchards in search of food. In some 

 cases, repeated border sprays were required to prevent extensive 

 damage from these GM larvae. 



Pesticide resistant Spotted Tentiform Leafminer (STLM) advanced 

 into central and eastern parts of the state. First generation STLM 

 counts averaging only 0.1 mine per leaf (10 mines per 100 observed 

 leaves) resulted in second generation counts averaging 0.8 mines per 

 leaf, and third generation counts averaging 2.8 per leaf. 



No IPM blocks experienced pre-harvest drop that could be char- 

 acterized as severe and clearly related to STLM injury. In most 



