SELETIVIDADE DE INSETICIDAS A Trichogramma pretiosum (HYMENOPTERA: TRICHOGRAMMATIDAE) COLETADO EM OVOS DE LAGARTA-ENROLADEIRA Bonagota salubricola (Meyrick, 1937) (LEPIDOPTERA: TORTRICIDAE) EM FRAIBURGO, BRASIL

Abstract

RESUMONeste trabalho foi avaliado o efeito de nove produtos fitossanitários utilizados no controle de pragas de macieiras em Fraiburgo (Brasil) sobre Trichogramma pretiosum Riley 1879 (Hymenoptera: Trichogrammatidae) coletado em ovos de Bonagota salubricola (Meyrick,1937) (Lepidoptera: Tortricidae). Para a realização dos bioensaios foram confeccionadas cartelas (2,5 x 0,5 cm) e colados 40 ± 2 ovos de Sitotroga cereallela (Oliv., 1819) (Lepidoptera: Gelechiidae), com idade inferior a 24 h e imersas nas caldas químicas durante cinco segundos. Os adultos do parasitóide foram expostos por 24 horas a resíduos secos de abamectin, clorpyrifos, carbaryl, fenitrothion, malathion, methidathion, phosmet, spirodiclofen e tebufenozide. O parasitismo, a emergência e a razão sexual foram avaliados. O delineamento experimental foi inteiramente casualizado com 10 tratamentos e 25 repetições. Clorpyrifos (150 mL/100L) foi classificado como nocivo, malathion (200 mL/100L) e carbaryl (360 mL/100L) se mostraram moderadamente nocivo, fenitrothion (150 mL/100L), phosmet (200 mL/100L), methidathion (100 mL/100L) e abamectin (100 mL/100L) foram levemente nocivo e tebufenozide (90 mL/100L) e spirodiclofen (25 mL/100L) foram inócuos. A razão sexual não foi afetada. Conclui-se que tebufenozide e spirodiclofen são os produtos fitossanitários que tiveram o menor impacto sobre o parasitismo de T. pretiosum e carbaril, methidation e abamectin tiveram o maior impacto sobre a emergência de T. pretiosum. Palavras chave: Lagarta-enroladeira-da-maçã; macieira; parasitóide de ovos; seletividade. ABSTRACTIn this work, was evaluated the effect of nine phytossanitary products used in the Apple Integrated Production, to Trichogramma pretiosum Riley 1879 (Hymenoptera: Trichogrammatidae) collected in Bonagota salubricola (Meyrick,1937) (Lepidoptera: Tortricidae). For the bioassay was confectioned paper cards of 2.5 x 0.5 cm, in which were glued 40 ± 2 eggs of Sitotroga cereallela (Oliv., 1819) (Lepidoptera, Gelechiidae) 24 hours old and immersing in the chemical solutions for five seconds. The adults of the parasitoid were exposed to dry residues of the abamectin, clorpyrifos, carbaryl, fenitrothion, malathion, methidathion, phomet, spirodiclofen e tebufenozide, allowing the parasitism for 24 hours. The parasitism rate, adult emergency and sexual ratio was evaluated. The experimental design was entirely randomized with ten treatments and 25 repetitions. Clorpyrifos (150 mL/100L) was harmful, malathion (200 mL/100L) and carbaryl (360 mL/100L) were moderately harmful. Fenitrothion (150 mL/100L), phosmet (200 mL/100L), methidathion (100 mL/100L) and abamectin (100 mL/100L) were slightly harmful and tebufenozide (90 mL/100L) and spirodiclofen (25 mL/100L) were harmless. The sex ratio was not affected. We conclude that tebufenozide and spirodiclofen are the pesticides that had the smallest impact on parasitism and carbaril, methidation and abamectin greater impact on the emergence of T. pretiosum.