11: Environmental Impact & Biodegradability

Hello! During week 11 I’ve been trying to cut down my report to only what I feel is necessary and working on my presentation. I’ve also added more detail and information on microbial larvicide, such as the impact environmentally, so I’ll expand on that section in this blog. 

Microbial larvicides like Bacillus thuringiensis israelensis (Bti) and Lysinibacillus sphaericus (Bs) generally only target mosquito larvae. They have an indiscernible impact on other insects in the environment as opposed to other insecticides, such as chemicals. Bti and Bs are also biodegradable, breaking down into harmless components in the environment. Additionally, many mosquito breeding sites are stagnant water bodies or wetlands, so although chemical insecticides can contaminate these environments, and harm fish, frogs, and beneficial bacteria, microbial larvicides degrade naturally and pose minimal threat to aquatic ecosystems.

Unlike chemical insecticides that can harm a wide range of insects and other organisms, microbial larvicides target mosquito larvae through unique procedures (which I expand on in my report), leaving other beneficial insects like pollinators and predators unharmed. There is a reduced risk to wildlife because chemical insecticides build up, which is a threat to wildlife like birds, fish, and mammals that feed on insects that inject toxic substances, while microbial larvicides obviously don’t have the same harmful effect, being bacteria. The reduced threat helps maintain a healthy ecosystem and supports biodiversity, thereby reducing the risk of long-term environmental damage by the larvicides. Regarding resistance, mosquitoes are also less likely to develop resistance to microbial larvicides because they target the biological processes of mosquito larvae, making it harder for them to develop resistance mechanisms. 

The use of microbial larvicide in other malaria stricken areas, such as several parts of Africa, has led to major decreases in transmission. Compounds including synthetic organic chemicals, bacterial larvicides, spinosyns, and insect growth regulators that I’ve mentioned before are used as larvicides [1]. Unfortunately, little information is available on the efficacy and effectiveness of the majority of these larvicides in Africa because of the lack of knowledge on implementing methods and the intensive effort needed for its monitoring. Therefore, I would believe the impact in Pakistan would be great, but there is no proper data available to confirm that. Thanks for reading this week’s blog! Next week is my final blog, and it will be after the senior project presentations. This week has presentation practices, and I’ll hopefully cut down my report enough. See you next week!