Table 2. Effect of various pear psylla control programs on honeydew 

 and sooty mold on pears. Spring Hill Orchard, Storrs, CT . 1979. 



Honeydew and sooty mold ratings 



a b 



Treatment programs Limb and leaf Clean fruit (I) 



A. Superior oil 3.0 75 



B. Superior oil pre-bloom; 1.0 94 



fenvalerate 2.4EC (Pydrin) 

 starting at white bud stage 



C. Superior oil pre-bloom; 2.4 88 



phosalone 3EC (Zolone) 

 starting at white bud stage 



D. Fenvalerate 2.4EC (Pydrin) 1.0 94 



E. Superior oil pre-bloom; 1.8 92 



fenvalerate 2.4EC (Pydrin) 

 starting at petal fall 



F. Check (untreated) 5.6 6 



a 



The following damage index was used: = clean; 1 to 2 = light; 

 3 to 4 = moderate; 5 to 6 = heavy. 



b 

 Based on 100 fruits per treatment. 



Figure 1 on the following page shows the seasonal history of 

 pear psylla populations for insecticide treatment programs A-E and 

 the check (F) . 



Programs utilizing 1-2 sprays of fenvalerate (Pydrin) (B, D, and 

 E) were the most effective in managing pear psylla and minimizing 

 damage. In these treatments, nymph and adult numbers averaged about 

 one or less per spur or limb tap from early May through late June. 

 In all other treatments, at least one of the developmental stages of 

 psylla exceeded this level. Phosalone (Zolone) (C) was moderately 

 effective but required 5 sprays and resulted in somewhat greater 

 damage than the fenvalerate (Pydrin) treatments. Oil used alone (A) 

 did not give acceptable control. 



Nymph populations in treatments A and F declined more slowly 

 and resurged sooner than in other treatments. Egg numbers also 

 resurged more rapidly on trees in treatments A, C and F. These 

 differences in population decline and resurgence rates may also have 

 contributed to differences in damage ratings among the treatments. 



