of 3.3, 6.0, and 30.0% of sampled fruit were injured 

 by PCs on phosmet-treated, Surround-treated, and un- 

 treated trees, respectively (Table 1). Results of labo- 

 ratory trials showed that in choice tests, where adults 

 could choose to feed on either an untreated or a Sur- 

 round-treated apple, all feeding occurred on untreated 

 apples (Table 2). However, in no-choice tests, where 

 adults remained hungry if they did not feed on the lone 

 type of apple provided, punctures on Surround-treated 

 fruit reached about one-fourth the number on untreated 

 fruit 24 and 48 hours after trials began and reached 

 about one-third the number on untreated fruit after 1 20 

 hours. 



Conclusions 



Our combined findings suggest that Surround has 

 definite potential as a material for preventing PC in- 

 jury. In the orchard trial, two sprays of Surround were 

 about half as effective as one spray of phosmet in pre- 

 venting curculio injury. In laboratory trials. Surround Acknowledgements 

 was completely effective in deterring feeding by PCs 

 on treated apples under conditions where untreated 

 apples were nearby but was less effective in the ab- 

 sence of accessible untreated apples. These results 

 indicate, therefore, that unless coverage of foliage and 



fruit by Surround is complete over space and continu- 

 ous over time. Surround may not be able afford total 

 protection against injury by PCs. A possible scenario 

 for future control of PC could involve treatment of the 

 great majority of trees in an orchard block with Sur- 

 round coupled with placement of odor-baited visual 

 traps at untreated trees to capture deterred but still- 

 foraging adults. 



As a final note, a new wettable-powder formula- 

 tion of Surround has been developed that is reported 

 to have greater residual effectiveness after rainfall than 

 the formulation used in our 1999 tests. This new for- 

 mulation is now officially registered for use on apples. 

 After an application of Surround, the foliage and fruit 

 are covered with a thin layer of white clay particles, 

 giving the tree a white appearance. Rather than being 

 a drawback, this is said to improve fruit color and fruit 

 size. 



We thank both Gary Puterka of the USDA Fruit 

 Research laboratory in Kearnesyville, WV and 

 Engelhard Corporation for providing the Surround and 

 adjuvant in our tests. 



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12 



Fruit Notes, Volume 64 (Number 3), Summer, 1999 



