Investigation of entomopathogenic fungi and their biological activities in ecological conditions of Duzce

This study was carried out in order to determine entomopathogenic fungi occuring in Duzce province, to determine the prevalence and distribution, and to determine their activity in different environmental conditions. A total of 45 isolates were obtained from 54 soil samples of different location, including 29 isolates of Beauveria bassiana and 16 isolates of Metarhizium anisopliae. The overall prevalence of entomopathogenic fungi was 33.33% and the prevalence rates were 24.07% and 11.11% for B. bassiana and M. anisopliae, respectively. M. anisopliae was isolated from altitudes ranging from 126-286 m and B. bassiana from altitudes ranging from 19-1298 m. In addition, B. bassiana isolates were obtained from farmland and forestry land and M. anisopliae isolates were mostly obtained from farmland and pasture areas. The isolates showed high lethal effect on the larvae of Tenebrio molitor after the directly spraying on the insect and indirectly on the substrate. Fungal isolates were applied against the larvae (1x106 conidi/ml). The mortality rates of B. bassiana YK11 and YK16, and M. anisopliae YK43, YK44 and YK45 isolates were reached to 100% within 7 days. Lethal times (LT50 and LT90) for 12 isolates showing 100% mortality was calculated. The LT50 and LT90 values were fluctuated from 43.08 to 183.61h for B. bassiana, while were fluctuated from 10.48 to 189.24h for M. anisopliae isolates. The efficacy of the isolates after the application to the wheat (1x107 conidi/ml dose) was lower in the 3% (w/v) aqueous suspension (<36.67%) but, mortalities significantly increased in the 10% aqueous suspension and mortality rates reached to 93.33% and 100% for the B. bassiana YK23 and YK26 isolates, respectively. In the same dose, B. bassiana YK14, M. anisopliae YK38 and YK45 isolates caused complete mortality against T. molitor larvae in 7 days after the soil application. B. bassiana and M. anisopliae isolates obtaining from Duzce province, exhibited a very high effect against T. molitor larvae under different conditions. Findings show that these fungi can be evaluated in biological control against insects causing agricultural damage.