Enhanced susceptibility of Tibraca limbativentris (Heteroptera: Pentatomidae) to Metarhizium anisopliae with sublethal doses of chemical insecticides

• Published in: Biological control Vol. 66; no. 1; pp. 56 - 64
• Main Authors: Quintela, Eliane Dias, Mascarin, Gabriel Moura, da Silva, Rodrigo Alves, Barrigossi, José Alexandre Freitas, Martins, José Francisco da Silva
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.07.2013
• Subjects: Biocontrol; Entomopathogenic fungi; Hemiptera; Metarhizium anisopliae; Neonicotinoid; Oryza sativa; Pentatomidae; Pyrethroid; Rice stalk stink bug; Synergism; Pyrethroid; Neonicotinoid; Entomopathogenic fungi; Rice stalk stink bug; Synergism; Biocontrol
• ISSN: 1049-9644; 1090-2112
• DOI: 10.1016/j.biocontrol.2013.03.018

[Display omitted] •Adults of Tibraca limbativentris are more susceptible to thiamethoxam than to lambda-cyhalothrin.•T. Limbativentris exhibited a natural resistance to Metarhizium anisopliae.•Subdoses of chemical insecticides enhanced susceptibility of T. limbativentris to M. anisopliae. 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 (5×106–5×108 conidia/mL) was combined with a sublethal dose (0.77ppm AI) of thiamethoxam compared with fungus only. A similar response on host mortality was observed for M. anisopliae at 5×107 conidia/mL in combination with sublethal dose of lambda-cyhalothrin at 9.33ppm (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 0.38ppm (AI). In a field experiment, the combination of M. anisopliae at 1×1012 viable conidia/ha with thiamethoxam at 12.5g (AI)/ha (¼ 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 (5×106 conidia/mL) and sublethal thiamethoxam (0.77ppm). 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.