Pathogenicity and thermal biology of mitosporic fungi as potential microbial control agents of Varroa destructor (Acari: Mesostigmata), an ectoparasitic mite of honey bee, Apis mellifera (Hymenoptera: Apidae)Pedro García-Fernández1, Cándido Santiago-Álvarez2 and Enrique Quesada-Moraga2
1 Área de la Producción Agraria, IFAPA, Centro Camino de Purchil, CAP, Junta de Andalucía, C/ Camino de Purchil s.n, 18071 Granada, Spain
2 Departamento de Ciencias y Recursos Agrícolas y Forestales, E.T.S.I.A.M., Universidad de Córdoba, Campus de Rabanales, Edificio C4 Celestino Mutis, Cordoba 14071, Spain
Received 16 January 2008 – Revised and accepted 7 July 2008 - Published online 21 October 2008
Abstract - Pathogenicity and thermal biology (tb) were investigated for entomopahogenic fungi isolates (EFI), which were examined as potential biocontrol agents of the ectoparasite Varroa destructor, the major disease of honey bees in Andalusia (Spain). All 16 of the assayed EFI were pathogenic to V. destructor, while two of them were exceptionally pathogenic to the mite: Metarhizium anisopliae 01/121-Su [AST 35.0 h, 100% mortality at 72 h post infection (p.i.)] and Beauveria bassiana 01/103-Su (AST 39.4 h, 96.0% mortality at 72 h p.i.). The tb of the five most virulent isolates against the mite was investigated at seven temperatures (10–40 °C) by using a modified generalized beta function that accounted for 79.8–96.4% of the data variance. Optimum temperatures and maximum temperatures for growth ranged from 24.9 to 31.2 °C and from 30.1 to 35.0 °C respectively. On the basis of their pathogenicity, thermal requirements and safety to honey bees, two isolates showed promise as candidates for V. destructor control.
Key words: Varroa destructor / Apis mellifera / entomopathogenic fungi / virulence / biological control / Beauveria / Metarhizium / Lecanicillium / Hirsutella / mite / parasites / mycoacaricides
© INRA, DIB-AGIB, EDP Sciences 2008