Laboratory evaluation of three strains of the entomopathogenic fungus Metarhizium anisopliae for controlling Hyalomma anatolicum anatolicum and Haemaphysalis punctata

Abstract

Hyalomma anatolicum anatolicum and Haemaphysalis punctata larval ticks were shown to be susceptible to different strains of entomopathogenic fungi Metarhizium anisopliae under laboratory conditions. To determine the susceptibility of H. anatolicum anatolicum and H. punctata to M. anisopliae, two suspensions of conidia were used (103 and 104 spores/ml). The treatments were conducted by immersing larval stage (at least 20 larvae/Petri dish) of H.anatolicum anatolicum and H.punctata in the spore suspension for 30 sec, followed by transferring to Petri dish containing moist filter paper. Control larval ticks were only immersed in 0.05% aqueous Tween 80. All treated and untreated ticks were observed by day interval up to day 18 to detect dead ticks and signs of mycosis. Comparative results of bioassays using three different fungal strains showed that all strains of M. anisopliae were highly pathogenic against two tick species used. The higher mortality rate was seen with strain of 689 when used in H. punctata and 685 in H. anatolicum anatolicum in comparison with the other strains(p