Evaluation of different high doses aqueous plant extracts for the sustainable control of Aedes aegypti mosquitoes under laboratory conditions

Abstract

Aedes aegypti mosquitoes represent a significant public health hazard as they serve as vectors for a variety of arboviral infections, including Dengue, Zika, and Chikungunya. This necessitates the development of efficacious vector control strategies. The current study conducted at the Medical Entomology laboratory of the Nuclear Institute for Food and Agriculture (NIFA) Peshawar, Pakistan, evaluated the potential use of locally sourced aqueous-based plant extracts against different life stages of Aedes aegypti mosquitoes. The utilization of plant extracts, including Parthenium hysterophorus, Nicotiana tabacum, Melia azedarach, and Fagonia indica, offers a potentially effective and ecologically sustainable strategy for pest control. The above excerpts present environmentally friendly alternatives that are biodegradable and have a little impact on the environment. These alternatives are in contrast to synthetic pesticides and contribute to the promotion of sustainable and ecologically responsible methods of pest control. The study tested various plant extracts, specifically those from Parthenium hysterophorus, Nicotiana tabacum, Melia azedarach, and Fagonia indica. These were examined at high concentrations to assess their toxicity to the mosquito species. The extract of P. hysterophorus demonstrated impressive efficacy, displaying 100 % effectiveness across all mosquito life stages. This was closely followed by N. tabacum, F. indica, and M. azedarach in decreasing order of efficacy. To better understand the potency of these plant extracts, their LC50 values were determined after 24, 48, and 72 h post-exposure. LC50 values, a common measure in toxicology, indicate the concentration at which 50 % of the test organisms are killed. Among the tested extracts, M. azedarach exhibited the highest LC50 values (1.703 %, 2.142 %, 2.640 %), implying lower toxicity, while P. hysterophorus showed the lowest LC50 values (0.120 %, 0.420 %, 0.975 %), indicating high toxicity to Aedes aegypti mosquito larvae. Based on the comparative analysis of toxicity, the extracts' efficiency order was established as follows: P. hysterophorus extracts > N. tabacum extracts > F. indica extracts > M. azedarach extracts. These findings suggest that P. hysterophorus and N. tabacum, particularly at a 3 % concentration, hold promising potential as components in eco-friendly integrated vector management (IVM) strategies. This approach would serve as an alternative to the traditional reliance on synthetic pesticides, which often pose environmental and health risks due to their residual toxicity.