Seleção de fungos entomopatogênicos para o controle de Oligonychus yothersi (McGregor) (Acari: Tetranychidae), na cultura da erva-mate (Ilex paraguariensis St. Hill.)

Abstract

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.

Susceptibility ofTetranychus ogmophallos(Acari: Tetranychidae) toBeauveria bassianaandMetarhizium anisopliae

“…Beauveria bassiana and M. anisopliae were pathogenic to T. ogmophallos, which is the first report on the pathogenicity of these fungi to this mite species. Other studies also have reported the pathogenicity of B. bassiana and M. anisopliae to tetranychid species, such as T. urticae (Alves et al 2002;Tamai et al 2002;Shi & Feng 2009;Moro et al 2011), T. evansi (Wekesa et al 2005), T. kanzawai (Sanjaya et al 2013), Mononychellus tanajoa (Bondar) (Acari: Tetranychidae) ( Barreto et al 2004), and oligonychus yothersi (McGregor) (Acari: Tetranychidae) (Oliveira et al 2002(Oliveira et al , 2004.…”

“…For example, Chandler et al (2000) collected records of 58 fungal species infecting at least 73 mite species. Among fungal entomopathogens, Beauveria bassiana (Balsamo) Vuillemin (Cordycipitaceae) and Metarhizium anisopliae (Metschnikof) Sorokin (Clavicipitaceae) species stand out (Oliveira et al 2004;Lacey 2017;Moro et al 2011). To date, few pathogens have been developed as commercial acaricides due to mass production issues or poor performance under field conditions (Arthurs & Bruck 2017).…”

“…Numerous mite species, including tetranychids, are infected by entomopathogenic fungi, predominantly Entomophthorales (e.g., Neozygites floridana) and Hypocreales (e.g., B. bassiana, Isaria spp. (formerly Paecilomyces), M. anisopliae, Hirsutella thompsonii (Fischer), Cladosporium cladosporioides (Fresen), Cephalosporium diversiphialidum Balazy, and Lecanicillium lecanii species (Zimmermann) [formerly Verticillium lecanii (Zimmermann)]) (Chandler et al 2000;Barreto et al 2004;Oliveira et al 2004;Maketon et al 2008;Bugeme et al 2009;Moro et al 2011;Sanjaya et al 2013;Geroh et al 2015;Lacey 2017;Nakai & Lacey 2017).…”

Susceptibility of larvae and adults ofMonochamus galloprovincialisto entomopathogenic fungi under controlled conditions

“…The suspensions obtained from each isolate were used according to the highest available conidia per millilitre and are presented in Table 2. These concentrations are based on spore availability and previous references (Dubois et al 2008;Marannino et al 2010;Oliveira et al 2004;Shimazu et al 2002. The suspensions were then stored until use, for less than a week at approximately 5 C.…”

Seleção De Isolados De Bacillus Thuringiensis Berliner Para Tetranychus Urticae Koch

“…Com isso, novas ferramentas de manejo de pragas devem ser disponibilizadas aos produtores, como o controle biológico com predadores e patógenos (Polanczyk et al, 2004;collier et al, 2007;Fatoretto et al, 2007), assim como de sua conservação, utilizando agrotóxicos seletivos (Monteiro, 2001;Poletti et al, 2008).…”