The western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), has become one of the most difficult insects to control in the intensive agriculture of southeastern Spain. However, resistance problems are quite different in two neighboring areas, Murcia and Almeria, with distinct production systems. Thirty-six field populations of western flower thrips from sweet pepper crops were collected in two different dates in Murcia and Almeria in 2005 and 2006. Western flower thrips populations collected were exposed to a diagnostic concentration of spinosad, methiocarb, acrinathrin, and formetanate. The results allowed the recognition of higher levels of resistance in Almeria compared with Murcia throughout the growing season. The mortality at the diagnostic concentration for spinosad (120 ppm) in western flower thrips populations ranged from 34 to 81% in Almeria, and from 73 to 100% in Murcia. The mortalities at the diagnostic concentration to acrinathrin (800 ppm) and formetanate (8000 ppm) were 17–31% in Almeria and 77–100% in Murcia, and 14–41% in Almeria and 48–99% in Murcia, respectively, indicating large geographic variations. Toxicity of methiocarb was higher for western flower thrips populations from both areas. However, mortality at the diagnostic concentration of methiocarb (2000 ppm) varied from 56 to 90% in Almeria, and it was from 94 to 100% in Murcia. The impact of production systems and agricultural practices of each area on the development and stability of insecticide resistance is discussed.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 101 • No. 5