Compatibilidade de Fungos Entomopatogênicos com Inseticidas NicotinóidesRESUMO -O efeito fungitóxico, in vitro, de três inseticidas neonicotinóides, acetamiprid (Saurus 200 PS), imidacloprid (Confidor 700 GrDA) e thiamethoxam (Actara 250 WG) em três concentrações (RM = recomendação média para campo, 0,7 RM e 1,3 RM), foi avaliado sobre os fungos entomopatogênicos Beauveria bassiana, Metarhizium anisopliae e Paecilomyces sp. O efeito dos inseticidas sobre a germinação dos conídios, o crescimento vegetativo e a produção de conídios também foi avaliado. Os resultados mostraram que os produtos não afetaram a germinação dos conídios, com exceção do acetamiprid na maior concentração (1,3 RM) onde ocorreu uma inibição (P<0,05) de M. anisopliae. O crescimento vegetativo foi inibido nos tratamentos acetamiprid, nas três concentrações, para B. bassiana e M. anisopliae. Também no tratamento thiamethoxam, na concentração RM e 1,3 RM o crescimento vegetativo foi inferior à testemunha para B. bassiana. Para Paecilomyces sp. o crescimento vegetativo foi superior ao da testemunha para os tratamentos 0,7 RM e RM de acetamiprid, todas as concentrações de imidacloprid e as duas menores de thiamethoxam. A produção de conídios foi menor para o tratamento de acetamiprid na maior concentração (1,3 RM) para os fungos Paecilomyces sp. e M. anisopliae e para imidacloprid na maior concentração (1,3 RM) para Paecilomyces sp. Já thiamethoxam inibiu a produção de conídios somente na menor concentração (0,7 RM) para M. anisopliae. Aumento de produção de conídios foi observado somente nos tratamentos acetamiprid nas duas menores concentrações (0,7 RM) e RM e thiamethoxam nas duas maiores (RM e 1,3 RM) para o fungo Paecilomyces sp. Assim, os inseticidas testados nas concentrações e formulações utilizadas mostraram, na maioria dos casos, compatibilidade com os entomopatógenos B. bassiana, M. anisopliae e Paecilomyces sp. Portanto, estes produtos poderão ser recomendados em programas de MIP, nas formulações e concentrações testadas, para o controle de pragas que tenham como inimigos naturais os entomopatógenos testados. PALAVRAS-CHAVE: Insecta, Beauveria bassiana, Metarhizium anisopliae, Paecilomyces sp.ABSTRACT -The in vitro fungitoxic effect of the neonicotinoid insecticides acetamiprid (Saurus 200 SP), imidacloprid (Confidor 700 WDGr) and thiamethoxam (Actara 250 WG) in three concentrations (AR= average field recommendation; 0.7 AR and 1.3 AR) to the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae and Paecilomyces sp. was studied. The effect of the insecticides on conidia germination, vegetative growth and conidiogenesis was compared. The insecticides had no effect on conidia germination, except under the highest concentration (1.3 AR) of acetamiprid, in which significant inhibition of M. anisopliae occurred. Vegetative growth of B. bassiana and M. anisopliae was significantly inhibited only by the three concentrations of acetamiprid treatment. Thiamethoxam treatment, in the AR and 1.3 AR concentrations, was significantly low...

The in vitro fungitoxic effect of three biofertilizers, Multibion TM and Supermagro used in organic agriculture and the neem oil (Azadirachta indica A. Juss) on the entomopathogenic fungi Metarhizium anisopliae and Beauveria bassiana was studied. These products were mixed in a medium where the two fungi were inoculated, and germination, vegetative growth and conidiogenesis were assessed. The biofertilizers showed to be less toxic for the two fungi whereas Multibion™ caused major inhibition on M. anisopliae, with reductions in germination (-37.74%), colony diameter (-30.26%) and conidiogenesis (-42.62%). Neem oil promoted a larger negative effect on B. bassiana, inhibiting germination (-45.27%), colony diameter (-36.62%) and conidiogenesis (-84.93%).

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Entomopathogenic Fungi Selection to Control Oligonychus yothersi (McGregor) (Acari: Tetranychidae) in Paraguay Tea Crops (Ilex paraguariensis St. Hill.) ABSTRACT-The virulence of strains of the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae and Paecilomyces fumosoroseus was evaluated on Oligonychus yothersi (McGregor) in laboratory. The bioassays for strain selection and determination of LD 50 and LT 50 were elaborated with leaf disks of Paraguay tea infested with 10 adult females of the mite. Groups of five disks were sprayed with 1 ml of the suspension standardized in 1.0x10 7 conidia per ml (50 mites per treatment) of each strain. After that, the disks were maintained floating in distilled water in plastic boxes (3 cm diameter and 1.5 cm height), in environmental chamber (temperature: 25 ± 1ºC; RH: 71 ± 10% and 12h photophase). Five days after the inoculation the total mortality was evaluated, and the dead mites were transferred to humid chamber. Six days after death, the sporulation in the cadavers was examined under an optical microscope. B. bassiana presented great potential as a microbial control agent, and can be incorporated in integrated pest management of the Paraguay tea red mite, O. yothersi. The B. bassiana strains UEL02, UEL08, UEL10, UEL50, CG082, CG166, CG375, CG424 and CG481, were the most virulent, with corrected and confirmed mortality higher than 70% and estimated value of CL 50 varying between 1.9x10 6 and 6.0x10 7 conidia per ml and TL 50 varying between 3.3 and 4.3 days.

Effect of Agrochemicals Based on Vegetable and Mineral Oil on the Viability of Entomopathogenic Fungi Beauveria bassiana (Bals.) Vuillemin, Metarhizium anisopliae (Metsch.) Sorokin and Paecilomyces sp. Bainier ABSTRACT -Many phytosanitary products have either vegetable or mineral oils as active ingredients or adjuvants. However, there are few papers that investigated the effects of these products on entomopathogenic fungi. Most studies refer to the use of oils as adjuvants in entomopathogen formulations with entomopathogens, and not as adjuvants in the tank mix. The objective of this study was to verify the compatibility of the entomopathogenic fungi Beauveria bassiana (Bals.) Vuillemin, Metarhizium anisopliae (Metsch.) Sorokin, and Paecilomyces sp. Bainier with agrochemicals based on mineral and vegetable oil in the tank mixes. Fourteen products were tested at their average recommended field rates. Conidial viability was estimated based on the percentage of germinated conidia and the number of colony-forming units (CFU).