Ground Larval Treatments
Throughout the mosquito season, PVMCD staff specifically targets mosquito vector habitats in deciduous swamps, stagnant ditches, flooded meadows, and artificial containers such as large tire piles. The purpose of this program is to reduce mosquito populations of vector species such as Aedes albopictus, Aedes vexans, Culex salinarius, and Ochlerotatus canadensis. This is accomplished by utilizing a naturally occurring soild bacteria called Bti (Bacillus thuringiensis israelensis) to eliminate mosquito larvae.
Bti is very safe for humans, animals, and the environment when used as directed. Once Bti spores reach the gut of a mosquito larva via ingestion, protein crystals form due to higher pH levels. The protein crystals will then attach to the wall of the mosquito’s gut, breaking it down and causing the mosquito to die shortly after. In addition to mosquito larvae, Bti is toxic to blackflies, also known as buffalo gnats.
When applying Bti to wetlands or vernal pools, indirect trophic effects are taken into consideration. For instance, a vernal pool with a high level of biodiversity will likely balance out mosquito populations and would therefore not require treatment. On the other hand, a wetland that yields a significant number of mosquitoes and is low in biodiversity would be an ideal location for treatment.
Catch Basin/Storm Drain Treatments
The larval control program also focuses on targeting the primary vector for West Nile virus, Culex pipiens and restuans, in catch basins. Culex pipiens and restuans prefer stagnant water full of bacteria, making catch basins an ideal habitat for this species. Currently, the pilot catch basin treatment program is only being offered to communities impacted by West Nile virus. Our goal is to extend this proactive mitigation service to additional communities in 2025.
How Bti Works
English