- Wetland areas maintained by the City of Westerville will be treated for mosquito larvae with a USEPA licensed larvicide The City of Westerville utilizes either Bti (Bacillus thuringiensis israelensis) or Spinosad (Saccharopolyspora Spinosa)for the control of larvae . These larvicides are natural soil bacterium and eliminate the insect in the larvae stage. Either product can be used in a time-release briquette in large basins and a smaller pellet form in smaller areas of water. The briquettes are placed at the low water level and are anchored to the bottom of the basin. Briquettes will be placed prior to spring rains, when water levels are low. Pellets will be placed on the surface of the water and will need to be applied more frequently.
- Samples of wetlands water will be taken and checked for the presence of larvae. If disease carrying larvae are suspected samples will be forwarded to laboratories for checks of species. When larvae counts or potential disease carrying species are found additional treatments will be performed. If Bti is not having the desired effect basins will be treated with Methoprene, a growth regulator that stops the larvae from hatching into adults.
- If adult mosquitoes are reported in any area of the City of Westerville mosquito traps will be set up and monitored in the effected locations. If the numbers of trapped mosquitoes warrants, fogging for the adults will be performed. As with the dipping technique the mosquito population can be determined and the presence of disease bearing insects can be determined.
- The City’s frequency of fogging operation will be determined by the numbers of mosquitoes found in the traps. Fogging to kill adults is successful only when the chemical in the fog comes in contact with the mosquito. The success of knock down of adults is much lower than the number of mosquitoes that can be eliminated by larvae control.
- Laboratory sampling will be performed in cooperation with the Franklin County Board of Health. This is a part performed as a part of the City’s contract with the Franklin County Board of Health. This gives the City of Westerville support from experts in the area of species identification and testing for potential disease carrying samples.
- Records of all mosquito control activities are kept on file at the Department of Public Service.
- The Department of Public Service has developed a map of the city showing all wetland areas. A plan has been established for each of these areas including access points, property owner permission to enter on private property, dosage levels, and the type of treatment to be used.
- Annually a schedule is developed for Larvae and Adult Mosquito Control Programs. These schedules are left very loose to allow for adjustments from the two forms of sampling mentioned earlier.
- The Department of Public Service has staff members who are licensed for the handling of mosquito control chemicals.
The overall goal of this program is to develop a system that reduces the mosquito population in the City of Westerville and has little or no impact on the environment of the treated areas. Additionally, the information provided here is designed to provide a level of comfort for the citizens of Westerville that the program is designed to reduce a nuisance and a potential health problem.