Majida Mohammad Abidfalhy Yaseen
Diseases transmitted by mosquitoes pose a threat to global public health. Culex pipiens transmits West Nile virus. The eco-friendly biological control, recruited by Beauveria bassiana, is a promising strategy. The current study aims to employ entomopathogenic fungi (B. bassiana) against the larval and adult stages of Cx. pipiens as an alternative method to chemical pesticides. The study investigated the effects of conidial suspension concentrations (3 x 105, 3 x 106, and 3 x 107 spores/ml) on four larval stages of Cx pipiens. The first instar was the most susceptible and showed significantly higher mortality at higher concentrations. The LC50 values for the first larval instar were 2.935 x 106 and 5.241 x 105 spores/ml after exposing for 24 and 72 h, respectively. For the second instar, the values were 5.988 x 106 and 1.845 x 106 spores/ml; for the third instar, 6.696 x 106 and 1.868 x 106 spores/ml; and for the fourth instar, 8.913 x 106 and 4.45 x 106 spores/ml, in the same intervals of time. Furthermore, mortality percentages for adults were 1.245 x 107 and 4.314 x 106 spores/ml for males, and 1.456 x 107 and 6.159 x 106 spores/ml for females after 24 and 72 h of treatment, respectively. The findings demonstrate that B. bassiana exhibits significant pathogenicity against both larval and adult stages of Cx. pipiens, with efficacy increasing at higher concentrations and longer exposure times. These results support its role as an eco-friendly biological control agent in reducing mosquito populations and limiting the transmission of West Nile virus.