Journal of Economic Entomology (2010) 103, 816-822

S. Civolani, S. Cassanelli, M. Rivi, G.C. Manicardi, R. Peretto, M. Chicca, E. Pasqualini and M. Leis (2010)
Survey of susceptibility to abamectin of pear psylla (Hemiptera: Psyllidae) in northern Italy
Journal of Economic Entomology 103 (3), 816-822
Abstract: The pear psylla, Cacopsylla pyri L. (Hemiptera: Psyllidae), is a relevant pest of pear, Pyrus communis L., trees in Emilia-Romagna region (northern Italy). The susceptibility to the insecticide abamectin was evaluated at different times of the year on C. pyri populations undergoing different control strategies within conventional, integrated, and organic farms. The tests performed were the egg spray and the topic and dip bioassay on adults. The larval mortality was evaluated by dip bioassay on treated leaves. The activity of P450-dependent monooxygenases, a relevant enzyme system involved in insecticide resistance of C. pyri, was also determined in adults by 7-ethoxycoumarin O-deethylation (ECOD assay). Tests on treated eggs and on larvae showed no significant differences in LC₅₀ and LC₉₀, although these values were always lower in individuals collected from organic farms in comparison with all other farms. Tests on overwintering adults revealed differences among populations, probably more related to collection time than to field pest control strategies. Unexpectedly, the ECOD assay on adults showed a slightly higher cytochrome P450 monooxygenase activity in the population undergoing organic control in comparison to others. Our results indicate that egg spray is the most reliable bioassay to verify data of open-field applications. Apparently, no resistance to abamectin has yet been developed by C. pyri in Emilia-Romagna.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Stefano Civolani, Edison Pasqualini, Marilena Leis, Gian Carlo Manicardi

Research topic(s) for pests/diseases/weeds:
pesticide resistance of pest

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Cacopsylla pyri	Pear (Pyrus)	Italy