title: Preliminary resistance screening on abamectin in pear psylla (Hemiptera: Psyllidae) in northern Italy.
abstract: In northern Italy (Emilia-Romagna region), integrated pest management has been used for several years against pear psylla, Cacopsylla pyri L. (Hemiptera: Psyllidae), a relevant pest of pear (Pyrus spp.) trees. After the outlawing of amitraz in 2005, the most common active ingredient involved is abamectin, a mixture of avermectin B1a and avermectin B1b. After the development of C. pyri resistance to azinphos methyl in southern France, we evaluated, by topical application, the different sensitivities to abamectin on C. pyri populations collected in orchards from Emilia-Romagna, where different field strategies were used, with alternative success in terms of pest management. The LC50 values ranged between 1.61 and 28.37 mg/liter, and they revealed variations more related to collection time than to field strategies. The failure of abamectin treatments against C. pyri in some Emilia-Romagna locations is probably unrelated to resistance development, but rather it is related to incorrect pest defense management, which could interfere with pest parasitoids and predators.
authors.affiliation: Department of Biology and Evolution, University of Ferrara, 44100 Ferrara, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Civolani
authors.forename: Riccardo
authors.initials: R
authors.lastname: Peretto
authors.forename: Luigi
authors.initials: L
authors.lastname: Caroli
authors.forename: Edison
authors.initials: E
authors.lastname: Pasqualini
authors.forename: Milvia
authors.initials: M
authors.lastname: Chicca
authors.forename: Marilena
authors.initials: M
authors.lastname: Leis
mesh_terms: D000818:Animals; D006430:Hemiptera / Q000187:drug effects*; D007300:Insect Control; D007305:Insecticide Resistance; D007558:Italy; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: C048324:abamectin; D007559:Ivermectin