Controlling mosquito larvae is effective because immature mosquitoes are concentrated in a small area. Once the larvae emerge from the water and become flying adults, they spread out making treatment more difficult. Cass County has twenty three employees that focus on treating standing water full time throughout the summer months. Each vector control employee is licensed to apply pesticides in North Dakota. All products used are registered for residential use by the Environmental Protection Agency. Click the products link for more information, labels, and MSDS.
Mosquito breeding sites in Cass County are mapped using GPS technology. Field aides routinely check these sites throughout the season for mosquito larvae or pupae. Treatments are made when necessary. With the use of backpacks and all terrain vehicles, crews were able to apply over 10,000 lbs of larvicide in 2004. Most of the products used are biological, environmentally friendly pesticides which will not harm non-target organisms. Site map
Mosquitoes have natural predators laying in wait to feast on them from larval stage through adulthood. These predators alone, however, are neither prevalent enough or physically able to do the job necessary to control the populations we see, for they are not preying exclusively on mosquitoes. A common misconception is that no rain is a good thing as far as mosquitoes go. In some ways this is true, but with regard to ongoing biological control it's not. When we go through a period of drought, the mosquito predator populations dwindle or cease to exist. A lack of rain may mean a lack of adult mosquitoes, but the mosquito eggs are still present awaiting rain (see mosquito biology section). When these rains finally do arrive, natural predator populations that would normally be present must now first repopulate in order to start eliminating mosquito larvae & pupae. This repopulation of predators can take time, giving mosquitoes plenty of time to reproduce several times over.
Some insects that prey on mosquito larvae are: water scorpion, damselfly naiad, dragonfly naiad, mayfly naiad, giant water bug, water beetle, beetle larva, crayfish, freshwater shrimp, tadpole.
Adult mosquitoes have predators as well. Frogs, dragonflies, birds and bats are known to eat mosquitoes. Research shows, however, that although mosquitoes do make up part of these creatures' diet, the number or mosquitoes they eat over the course of a night are not significant enough to make a substantial difference in mosquito populations. |
