Possible Synergistic Effect of Combined Metarhizium anisopliae and Fenitrothion for Control of German Cockroach (Blattella germanica) as a Novel Approach

Mohammad Reza Khaksar; Majid Kababian; Roohollah Fateh; Abedin Saghafipour; Hassan Vatandoost; Mona Sharififard

doi:10.18502/jad.v15i3.9818

Mohammad Reza Khaksar Department of Occupational Health, Faculty of Health, Qom University of Medical Sciences, Qom, Iran
Majid Kababian Student Research Committee, Qom University of Medical Sciences, Qom, Iran
Roohollah Fateh Cellular and Molecular Research Center, Qom University of Medical Sciences. Qom, Iran
Abedin Saghafipour Department of Public Health, School of Health, Qom University of Medical Sciences, Qom, Iran
Hassan Vatandoost Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
Mona Sharififard Department of Medical Entomology and Vector Control, School of Public Health, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

DOI: https://doi.org/10.18502/jad.v15i3.9818

Keywords: Blattella germanica, Metarhizium anisopliae, Fenitrothion, Synergism

Abstract

Background: Cockroaches are one of the most common pests in many residential areas. In this study, the simultaneous effects of fungi, Metarhizium anisopliae and fenitrothion-coated baits on the mortality rate of the German cockroach nymphs were investigated.

Methods: To determine the lethal level of fenitrothion insecticide, a bioassay test was performed on the last instar nymphs of the German cockroach reared at insectarium conditions. Various toxic concentrations of fenitrothion (0.1%, 0.3%, 0.5%, 0.7%, 0.9%, 1.5%, and 2%) were used. Different concentrations of M. anisopliae (1×10⁴, 1×10⁵, 1×10⁶, 1×10⁷, 1×10⁸ Conidia/ ml) were also applied to nymphs. Eventually, we combined the effective dose of fenitrothion (0.93%) with the effective concentration of M. anisopliae (6.6 ×10⁶ Conidia/ml) to provide the fungus-coated bait to attract insects. Mortality was recorded 24–96 hours after exposure to the toxic bait. The resulting data were subjected to Probit analysis.

Results: The results of applying M. anisopliae spores with fenitrothion composition showed that the mortality rate of German cockroach nymphs was significant. Therefore, the optimal dose of fenitrothion used in combination with M. anisopliae seems essential to reduce the German cockroach nymphs.

Conclusion: The results of this study can be considered a suitable method as a mixture with low cost and minimal damage to the environment and other organisms.