Combining DL-Methionine and Bacillus thuringiensis Subspecies israelensis: Prospects for a Mosquito Larvicide

Bacillus thuringiensis (Bt)-based biopesticide: Navigating success, challenges, and future horizons in sustainable pest control

The global demand for food production is escalating, necessitating innovative approaches to mitigate pest-related crop losses. Conventional pest management using synthetic pesticides has several drawbacks, promoting the search for eco-friendly alternatives such as biopesticides. Among these, Bacillus thuringiensis (Bt)-based biopesticides have emerged as a promising option due to their specificity, sustainability, and safety. This article reviews the success and application of Bt as a biopesticide, analysing its environmental impacts, formulation strategies, marketing trends and associated challenges. The environment impact of Bt is multifaceted, influencing soil ecosystems, plant-associated habitats, and non-target organisms. It interacts dynamically with soil invertebrates and affects both aquatic and terrestrial ecosystems, demonstrating a complex ecological footprint. The market for Bt-based biopesticide is expanding, driven by their proven efficacy and eco-friendliness with projections indicating continued growth. Despite the promising market trends, regulatory hurdles and formulation complexities remain significant obstacles. Addressing these challenges require collaborative efforts to streamline processes and enhance market acceptance. Nonetheless, the future of Bt-based biopesticide appears promising. Ongoing research is focused on advanced formulations, expanding the range of targeted pests and fostering regulatory cooperation, underscoring the pivotal role of Bt-based biopesticide in sustainable agriculture.

Novel effective mosquito larvicide DL-methionine: Lack of toxicity to non-target aquatic organisms

Mosquito larvicides are an effective tool for reducing numbers of adult females that bite and potentially spread pathogenic organisms. Methionine, an essential amino acid in humans, has been previously demonstrated to be a highly effective larvicide against four (4) mosquito species in three (3) genera, Anopheles, Culex and Aedes. The aim of the present study was to determine the potential impact on non-target aquatic organisms of methionine applied as a mosquito larvicide. DL-methionine concentrations ranging from 0.06% to 1.00% were used; wherein the highest concentration of 1.00% would result in 100% mortality within 48 h in mosquitoes. Acute toxicity assays were conducted in accordance with the US Environmental Protection Agency (US EPA) guidelines for the water flea (Daphnia magna Straus; Cladocera: Daphniidae) and the fathead minnow (Pimephales promelas Rafinesque; Cypriniformes: Cyprinidae). Water fleas and fish were placed directly into the solutions in glass containers and tanks for 48-hours and 96-hours, respectively. When applied within the above-mentioned range of effective mosquito larvicide concentrations, DL-methionine meets US EPA criteria as a "practically non-toxic" pesticide for both species. These results suggest that methionine is a viable alternative to current mosquito larvicide options, which are typically classified as moderately to highly toxic and may be a valuable addition to a mosquito integrated pest management program.