Preliminary study on virulence of some isolates of entomopathogenic fungi in different developmental stages of Boophilus annulatus in Iran

ABSTRACT

To evaluate the virulance of 11 isolates of native entomopathogenic fungi as biocontrol agent of Boophilus annulatus, in this study, 4 three months old calves were used for tick rearing. 7 Different developmental stages of the ticks, Boophilus annulatus were inoculated by 10 conidia/ml dilution of the fungal isolates in the presence of control groups. The mortality, egg hatchability and reproductive efficiency were determined in different treatments and control groups and the results were analized statisticaly. Metarhizium anisopliae strains DEMI001 and IRAN437C, Beauveria bassiana strain IRAN403C, and Lecanicillium psalliotae strain IRAN468C were the most virulent strains in comparison with their relative strains and caused 80 -100%, 20 - 80%, 0 - 40% and 0- 40% mortality for engorged females respectively. All 11 tested fungi reduced egg laying capability of the ticks several days before their death. The obtained data showed that the entomopathogenic fungi can affect all developmental stages of Boophilus annulatus, but their efficiency varies considerably according to the fungal species and strains. It is demonstrated for the first time the pathogenic effect of Lecanicillium psalliotae against Boophilus annulatus