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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Milbemectin resistance in Tetranychus urticae (Acari: Tetranychidae): selection, stability and cross-resistance to abamectin

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Nicastro, Roberto Lomba [1] ; Sato, Mario Eidi [2, 1] ; Da Silva, Marcos Zatti [1]
Total Authors: 3
[1] APTA, Inst Biol, Lab Econ Entomol, BR-1300970 Campinas, SP - Brazil
[2] Inst Biol, BR-13092543 Campinas, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Experimental and Applied Acarology; v. 50, n. 3, p. 231-241, MAR 2010.
Web of Science Citations: 26

Studies on artificial laboratory selections with milbemectin, stability of milbemectin resistance and possible cross-resistance with abamectin were carried out with Tetranychus urticae Koch to provide basic information for a milbemectin resistance management program. Selections for resistance and susceptibility to milbemectin were performed in a population of T. urticae, collected from a commercial chrysanthemum field in the State of Sao Paulo, Brazil. After six selections for resistance and five selections for susceptibility, susceptible (S) and resistant (R) strains of T. urticae to milbemectin were obtained. The resistance ratio (R/S) at the LC(50) reached 409-fold value. The stability of milbemectin resistance was also studied under laboratory conditions, using a population with initial frequency of 75% of resistant mites. The frequencies of milbemectin resistance were evaluated monthly for a period of 7 months. In order to observe possible correlation between milbemectin and abamectin resistance, the frequencies of abamectin resistance were also evaluated for that population, during the same period. The frequency of milbemectin resistance decreased from 75 to 14.5%, while the percentage of abamectin resistant mites decreased from 57 to 9.1%, in 7 months. The frequencies of milbemectin and abamectin resistance were also evaluated in 25 field populations of T. urticae, collected from several crops in the State of Sao Paulo. The frequencies of milbemectin resistance varied from 4.1 to 89.5%, and of abamectin, from 7.0 to 90.5%. A positive and significant correlation was observed between the frequencies of milbemectin and abamectin resistance, indicating positive cross-resistance between these acaricides. The results indicate that abamectin should be avoided for managing milbemectin resistance in T. urticae. This is the first report on milbemectin resistance in T. urticae in Brazil. (AU)

FAPESP's process: 05/04454-0 - Management of two-spotted spider mite, Tetranychus urticae Koch, on strawberry and ornamental plants, in the state of São Paulo
Grantee:Mário Eidi Sato
Support Opportunities: Regular Research Grants
FAPESP's process: 07/02748-1 - Resistance of Tetranychus urticae Koch to milbemectin and abamectin acaricides and management of strawberry and ornamental plants pest mites using predatory mites from Phytoseiidae family
Grantee:Roberto Lomba Nicastro
Support Opportunities: Scholarships in Brazil - Master
FAPESP's process: 07/08612-4 - Studies on pesticide resistance on thrips (Frankliniella occidentalis) and mites (Tetranychus urticae), in several crops, and host preference of these pests on ornamental plants in the State of São Paulo
Grantee:Mário Eidi Sato
Support Opportunities: Regular Research Grants