Effects of combining the fungi Beauveria bassiana and Metarhizium anisopliae on the mortality of the tick Amblyomma variegatum (ixodidae) in relation to seasonal changes.
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Date
2005-03-06
Authors
Hassanali, Ahmed
Mueke, J. M.
Kaaya, G. P.
Maranga, R. O.
Journal Title
Journal ISSN
Volume Title
Publisher
Springerlink
Abstract
The effect of formulation, fungal concentration, type and seasonal changes on the mortality of the tick
Amblyomma variegatum was investigated. A previous study demonstrated high pathogenicity of strains of
the fungi Beauveria bassiana and Metarhizium anisopliae against the ticks Rhipicephalus appendiculatus and
Amblyomma variegatum (Kaaya et al. J Invertebr Pathol 1996; 67: 15–20). The present study was undertaken
to explore possible additive or synergistic effects of the two fungi on A. variegatum. The effects of oil
and water formulations at different concentrations of each fungus and combination of the two on the
mortality of A. variegatum in the laboratory and in the field during the wet and dry seasons were determined
and compared. The oil formulation performed better in all assays, with highest tick mortality of 92%
occurring during the wet season at conidia concentration of 1 · 1010 conidia/ml of the mixed fungi compared
to 49% for the water formulation at similar conidia concentration. However, at the same conidial
concentration during the dry season, mortalities in the field were relatively low with the mixture of the fungi
recording 24% and 17% tick mortality for the oil and water formulation respectively. The effect of infecting
the ticks with a cocktail of the two fungi was inconclusive under more controlled conditions in the laboratory
but field results under both wet and dry seasons indicated significant differences between the separate
and mixed fungi infections. The results demonstrate a potential of cocktail formulations in the control of
ticks and possibly of other arthropod pests.
Description
DOI:10.1007/s11046-005-3374-y
Keywords
biocontrol, cocktail, formulation
Citation
Mycopathologia (2005) 159: 527–532 DOI: 10.1007/s11046-005-3374-y