13 



Table 1. Number of ABLM moths captured on red visual traps in two positions 

 at tight cluster and early pink, in seven commercial orchards. 



Trap position 



Mean ABLM captured per trap 

 Tight cluster Early pink 



Horizontal in canopy 

 Vertical in trunk 



l.l a* 

 3.8 a 



9.3 a 

 18.1 a 



*Means within a column not followed by the same letter are significantly 

 different at the 5% level. 



Our results in 1986 suggest that if cumulative captures in this new 

 position exceed 3-6 ABLM per trap by tight cluster or 18-22 by early pink, an 

 insecticide treatment for ABLM may be desirable. This is a very rough 

 approximation, based on results in only 7 blocks. We will continue testing in 

 1987 to refine these estimates. In the meantime, wc liave continued confidence 

 in the treatment threshold of 13 ABLM per trap by early pink for traps placed 

 in the tree canopy. 



We also tested a spray tank additive, Nu -Fi lm-17 ' '" (6 oz./lOO gal.), with 

 a single Thiodan^'^ (1 Ib./lOO gal.) treatment for ABLM at tight cluster. 

 Growers using Thiodan for ABLM usually have found 2-3 pre-bloom applications 

 to be necessary for good control. We hoped tliat Nu-Film-17, advertised as a 

 spreader-sticker which extends the residual activity of insecticides, would hel[o 

 to reduce the numbc of Thiodan applications needed. 



Our results did not bear this out, however (Table 2), Nu-Film-17 appeared 

 to have no influence on the efficacy of Thiodan. It is noteworthy that both 

 the single application of Thiodan and the Thiodan + Nu-Film-17 reduced ABLM 

 mine densities, but not below our threshold of 0.13 first generation mines per 

 leaf, supporting previous evidence that a single application of Thiodan pre- 

 bloom usually is not sufficient to control ABLM. 



Table 2. Effectiveness of Thiodan^'" + Nu-Film-17'''", Thiodan ilone, and no 

 treatment against ABLM. Applications were made at tight cluster in 

 four commercial orchards. 



Treatment 



1st Generation 

 mines per leaf 



Thiodan 



Thiodan + Nu-Film-17 



Untreated 



0.13 a* 

 0.14 a 

 0.26 b 



*Means within a colunn not followed by the same letter are significantly 

 different at the 5% level. 



