5. 



Adult populations in early spring were lowest on treatments 

 which received oil (A, B, C and E) . Zwick and Westigard (1978) in 

 Oregon reported a delay and a reduction in egg laying by overwinter- 

 ing pear psylla adults attributable to the use o£ petroleum oils. 

 We observed a similar delay in egg laying on oiled pear trees at 

 Storrs in 1978. We did not note a delay or reduction in egg lay- 

 ing in 1979 but we suspect that our oil treatments were applied too 

 late to have gained that benefit. 



Hoyt , Westigard, and Burts (1978) have reported fenvalerate 

 (Pydrin) to be highly toxic to predators of spider mites in pear 

 orchards in the Pacific Northwest. In view of the current lack of 

 effective insecticides for pear psylla control, fenvalerate (Pydrin) 

 appears to be of considerable value, especially when used as pre- 

 bloom treatments. Early season treatments might allow predators 

 to recover in time to help manage summer spider mite populations. 



Connecticut is now in the process of applying for a special 

 state registration to allow the use of fenvalerate (Pydrin) in 1981 

 for the control of pear psylla on pears. 



A summer treatment of amitraz (BAAM) applied to all plots was 

 not highly effective in controlling pear psylla in our tests, and 

 was associated with considerable leaf scorch. It could not be 

 determined whether BAAM was directly responsible for this injury. 

 A period of several days of high temperatures and humidity following 

 the treatment may have contributed to the appearance of damage. 

 Further tests are needed to evaluate more fully the role of BAAM 

 for pear psylla control on pears in Connecticut. 



References 



Hoyt, S.C, P.H. Westigard, and E.C. Burts. 1978. Effects of two syn- 

 thetic pyrethroids on the codling moth, pear psylla, and various 

 mite species in northwest apple and pear orchards. J. Econ . 

 Entomol . 71: 431-434. 



Zwick, R.W. and P.H. Westigard. 1978. Pre-bloom petroleum oil 

 applications for delaying pear psylla (Homoptera: Psyllidae) 

 oviDOsition. Can. Entomol. 110: 225-336. 



