Does Spring Flooding Cause More Mosquitoes?

If your area experiences flooding in the spring months, it may cause a temporary increase in mosquitoes. In fact, some species of mosquito thrive in flood plains and regions that experience seasonal flooding. In this article, we take a look at the mosquito lifecycle, types of mosquitoes, and what you can do to repel mosquitoes away from your property.

Does Spring Flooding Cause More Mosquitoes?

Understanding the Mosquito Lifecycle

All mosquito species go through four distinct lifecycle stages.

Eggs

Depending on the mosquito species, the adult females may lay single eggs or multiples known as rafts. Typically, the eggs float on the surface of the water and are visible to the eye if you look closely enough.

Larvae

The larvae hatch from the eggs and wriggle in the water, swimming around, which is why they have the moniker wrigglers. Mosquito larvae filter organisms from the water to feed, molting their exoskeleton as they grow. They’ll moth four times over two weeks, depending on the water temperature and the mosquito species.

Pupae

The larvae reach the tumbler or pupa stage after molting a fifth time. If disturbed, the pupa will lie on the surface and dive below the waterline.

Adult Mosquitoes

After completing the pupa stage, the adult mosquito emerges on the surface. The mosquito then remains on top of the water, relying on the surface tension to keep it afloat while its wings dry and its body hardens.

The Permanent Water Mosquito

Most mosquito species found in urban areas are of the permanent water variety. Permanent water mosquitoes breed in stagnant or standing water collecting in bird baths, unused pools, containers, and on tarps where water pools. Rainy seasons can create puddles in areas that are usually dry, and mosquitoes will seek out any form of standing water to breed and lay eggs.

The Floodwater Mosquito

The Inland Floodwater Mosquito (Aedes vexans) lays its eggs in dry areas where there is a high likelihood of seasonal flooding. The eggs need a drying-out period and can survive for up to a year without any water contact. When the water arrives, it triggers the hatching process.

Floodwater mosquitoes are typically found around the edges of irrigation furrows, moist pastures or swamplands, ditches, swales, and other similar habitats. When the eggs become saturated with water, they start to hatch. That’s why you’ll notice an increase in the local mosquito population in your area after flooding events.

Handling Floodwater Mosquito Infestations

It’s easy to limit the population of permanent water mosquitoes on your property by eliminating sources of standing water where they lay eggs. Remove all open containers that might catch rain and provide a breeding ground for the insects.

However, there’s not much you can do to curb the population of floodwater mosquitoes in your area. These insects can fly for miles from where they hatch in search of someone to bite. The best strategy is to avoid areas where spring flooding occurs and use insecticides and repellents.

Use insecticide on areas of your property that experience flooding in the spring, such as the verges of drainage ditches. Use repellants with the active ingredient, DEET, to stop them from landing on you and biting.

The Inland Floodwater mosquito doesn’t transmit West Nile Virus, but it can carry Eastern Equine Encephalitis, which is highly pathogenic, and in some cases, fatal.

Mosquito Treatment – Three-Step Guide

Here’s a three-step guide to help you eliminate mosquitoes from your property.

Step 1 – Eliminate Prospective Breeding Areas for Mosquitoes

Remove all sources of standing water on your property. Dump water left on tarps, pool covers, and in containers around your property. Preferably, dump it in the sewer if you can.

Step 2 – Apply Larvicide

Apply larvicide to areas where you can’t drain standing water. The larvicide prevents the eggs from hatching into wrigglers and eventually into pupae and adult mosquitoes. Insecticides stop mosquitoes during the undeveloped stage of the lifecycle.

Step 3 – Apply Insecticide

Spray your grass with insecticide before the start of the spring rains to prevent any eggs that might be lurking in the turf.