Mowing Grass in Water-Detention Basins Increases Mosquito Populations

Mowing grass and weeds is a useful way of managing some pests. For example, clearing yards and fields is one way of managing ticks without using insecticides because mowing discourages rodents — on which some ticks feed on.

However, for other situations it may have the opposite effect. A study of the West Nile virus risk associated with water-detention basins in Central Illinois took an unexpected turn when land managers started mowing the basins. The mowing of wetland plants in basins that failed to drain properly led to a boom in populations of the northern house mosquito (Culex pipiens), which can carry and transmit the deadly virus, researchers report. A paper describing their findings was published in the journal Ecological Applications.