Author(s): QUINTELA, E. D.; MASCARIN, G. M.; SILVA, R. A. da; BARRIGOSSI, J. A. F.; MARTINS, J. F. da S.

Summary: This study investigated the interaction of the fungus Metarhizium anisopliae (Metsch.) Sorok. with sublethal doses of synthetic chemical insecticides thiamethoxam and lambda-cyhalothrin for the control of Tibraca limbativentris adults under laboratory and field conditions. Median lethal time (LT50) was reduced significantly when M. anisopliae (5 x 106?5 x 108 conidia/mL) was combined with a sublethal dose (0.77 ppm AI) of thiamethoxam compared with fungus only. A similar response on host mortality was observed for M. anisopliae at 5 x 107 conidia/mL in combination with sublethal dose of lambda-cyhalothrin at 9.33 ppm (AI). Additionally, the thiamethoxam-fungus combination increased overall mortality and percent mycosed insects in comparison to their counterparts alone. Increasing fungus concentration did not increase insect susceptibility when combined with thiamethoxam either at 0.77 or 0.38 ppm (AI). In a field experiment, the combination of M. anisopliae at 1 x 1012 viable conidia/ha with thiamethoxam at 12.5 g (AI)/ha (1=4 full dose) synergistically increased mortality and mycosis of adults of T. limbativentris. Therefore, enhanced T. limbativentris control could potentially be achieved within label rates of fungus (5 x 106 conidia/mL) and sublethal thiamethoxam (0.77 ppm). The strategy of using sublethal doses of chemical insecticides in combination with entomopathogenic fungi is a promising approach to battle the rice stalk stink bug in rice fields.

Publication year: 2013

Types of publication: Journal article

Unit: Embrapa Rice & Beans

Keywords: Arroz, Biocontrol, Inseticida, Metarhizium anisopliae, Oryza sativa, Rice stalk stink bug, Tibraca limbativentris, entomopathogenic fungi