Comprehensive lethal effects and transgenerational impact of Metarhizium anisopliae on Anopheles sinensis across all...

Mosquitoes are major vectors of disease and pose a significant threat to public health. Chemical insecticides face resistance and environmental issues, prompting the need for eco-friendly alternatives such as entomopathogenic fungi. However, their potential across mosquito life stages remains underexplored. As a primary malaria vector in East Asia, Anopheles sinensis remains understudied in terms of biological control approaches.

Four effective fungal strains were initially screened from 22 fungal isolates based on their pathogenicity against An. sinensis larvae. Among them, strain Metarhizium anisopliae (Ma)421 demonstrated the best overall performance when further assessed for its mosquito-killing activity at the egg, pupa and adult stages, as well as its sporulation capacity on mosquito cadavers. Fungal infection reduced hatching rates, impaired larval pupation and adult emergence, and caused morphological deformities in newly emerged adults-such as malformed wings and legs-ultimately leading to mortality. Further analysis of Ma421 revealed a significant suppression of blood-feeding behavior, reduced egg-laying, and lower hatching, pupation and adult emergence rates in the next generation. These findings indicated that Ma421 induced transgenerational effects by decreasing reproductive success in subsequent generation, which is an important finding with promising implications for sustainable mosquito control.

This study fills a significant gap in the fungal-based biological control of An. sinensis, with the multistage efficacy of Ma421 highlighting its potential for use in integrated vector management. Its transgenerational impact further underscores its potential as an eco-friendly alternative to chemical insecticides, supporting its incorporation into sustainable mosquito management strategies. © 2025 Society of Chemical Industry.