Persistent Link:
http://hdl.handle.net/10150/198219
Title:
Biotype Designations and Insecticide Susceptibility of Southwestern Bemisia tabaci
Author:
Dennehy, Timothy J.; DeGain, Benjamin A.; Harpold, Virginia S.; Nichols, Robert J.
Affiliation:
University of Arizona. Tucson, AZ; Cotton Incorporated, Cary, NC
Issue Date:
Aug-2007
Publisher:
College of Agriculture, University of Arizona (Tucson, AZ)
Journal:
Cotton: A College of Agriculture and Life Sciences Report
Abstract:
We report biotype identifications and susceptibility to insecticides of whiteflies (Bemisia tabaci) collected from cotton, vegetables, melons and ornamental plans during the 2005 season. No major problems with field performance of insecticides against whiteflies were confirmed in 2005 in Arizona. Whitefly resistance to pyriproxyfen did not increase, relative to levels recorded in 2004. However, we detected pyriproxyfen resistance in all Arizona whitefly samples tested. A single sample collected from cotton in Holtville, CA, had no detectable resistance to pyriproxyfen. Samples from cotton in Buckeye, Coolidge, Scottsdale, and stanfield, Arizon,a had the highest levels of resistance, with > 31-45% of eggs surviving diagnostic concentration bioassays of 0.1 ug/ml pyriproxyfen. Whitefly susceptibility to buprofezin (Applaud®/Courier®) has not changed significantly since 1997. Resistance to synergized pyrethroids (e.g., Danitol® + Orthene®) has decreased strikingly on a statewide basis since 1995, though unacceptably high frequencies of resistant whiteflies were detected in some 2005 collections from all commodities sampled. Whiteflies collected from Arizona cotton, melons, and vegetables continued to be highly susceptible to imidacloprid (Admire®/Provado®). One whitefly collection from poinsettias in Phoenix (05-39) was substantially less susceptibile to imidacloprid, and the related neonicotinoid insecticides, acetamiprid, and thiamethoxam. Regression analysis yielded a significant correlation between acetamiprid and thiamethoxam. Whiteflies from cotton that were least susceptibile to acetamiprid were also significantly less susceptible to thiamethoxam (Actara®/Centric®/Platinum®). The most worrisome of our 2005 findings was that 6 out of 13 samples of whitefly-infested poinsettias collected from retail stores in metropolitan Tucson and Phoenix consisted of only the Q biotype of Bemisia tabaci. The plants were infested with very low whitefly numbers and thus we were unable to establish them in laboratory cultures and evaluate their resistance status. The Q biotype is native to Spain and was first detected in the US by our group in 2004 on a sample taken from poinsettias. Our concern is that the Q biotype strain we detected in 2004 was highly resistant to a broad range of insecticides used to manage whiteflies in Arizona. None of the 26 field collections evaluated in 2005 was the Q biotype.
Keywords:
Agriculture -- Arizona; Cotton -- Arizona; Resistance management
Series/Report no.:
az1437; Series P-151

Full metadata record

DC FieldValue Language
dc.titleBiotype Designations and Insecticide Susceptibility of Southwestern Bemisia tabacien_US
dc.contributor.authorDennehy, Timothy J.en_US
dc.contributor.authorDeGain, Benjamin A.en_US
dc.contributor.authorHarpold, Virginia S.en_US
dc.contributor.authorNichols, Robert J.en_US
dc.contributor.departmentUniversity of Arizona. Tucson, AZen_US
dc.contributor.departmentCotton Incorporated, Cary, NCen_US
dc.date.issued2007-08-
dc.publisherCollege of Agriculture, University of Arizona (Tucson, AZ)en_US
dc.identifier.journalCotton: A College of Agriculture and Life Sciences Reporten_US
dc.description.abstractWe report biotype identifications and susceptibility to insecticides of whiteflies (Bemisia tabaci) collected from cotton, vegetables, melons and ornamental plans during the 2005 season. No major problems with field performance of insecticides against whiteflies were confirmed in 2005 in Arizona. Whitefly resistance to pyriproxyfen did not increase, relative to levels recorded in 2004. However, we detected pyriproxyfen resistance in all Arizona whitefly samples tested. A single sample collected from cotton in Holtville, CA, had no detectable resistance to pyriproxyfen. Samples from cotton in Buckeye, Coolidge, Scottsdale, and stanfield, Arizon,a had the highest levels of resistance, with > 31-45% of eggs surviving diagnostic concentration bioassays of 0.1 ug/ml pyriproxyfen. Whitefly susceptibility to buprofezin (Applaud®/Courier®) has not changed significantly since 1997. Resistance to synergized pyrethroids (e.g., Danitol® + Orthene®) has decreased strikingly on a statewide basis since 1995, though unacceptably high frequencies of resistant whiteflies were detected in some 2005 collections from all commodities sampled. Whiteflies collected from Arizona cotton, melons, and vegetables continued to be highly susceptible to imidacloprid (Admire®/Provado®). One whitefly collection from poinsettias in Phoenix (05-39) was substantially less susceptibile to imidacloprid, and the related neonicotinoid insecticides, acetamiprid, and thiamethoxam. Regression analysis yielded a significant correlation between acetamiprid and thiamethoxam. Whiteflies from cotton that were least susceptibile to acetamiprid were also significantly less susceptible to thiamethoxam (Actara®/Centric®/Platinum®). The most worrisome of our 2005 findings was that 6 out of 13 samples of whitefly-infested poinsettias collected from retail stores in metropolitan Tucson and Phoenix consisted of only the Q biotype of Bemisia tabaci. The plants were infested with very low whitefly numbers and thus we were unable to establish them in laboratory cultures and evaluate their resistance status. The Q biotype is native to Spain and was first detected in the US by our group in 2004 on a sample taken from poinsettias. Our concern is that the Q biotype strain we detected in 2004 was highly resistant to a broad range of insecticides used to manage whiteflies in Arizona. None of the 26 field collections evaluated in 2005 was the Q biotype.en_US
dc.subjectAgriculture -- Arizonaen_US
dc.subjectCotton -- Arizonaen_US
dc.subjectResistance managementen_US
dc.identifier.urihttp://hdl.handle.net/10150/198219-
dc.relation.ispartofseriesaz1437en_US
dc.relation.ispartofseriesSeries P-151en_US
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