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Aquatic and Unusual: Mayflies in Virginia

Did you know that mayflies are aquatic creatures? No wonder Virginia sees them come in droves!

mayfly on a leaf

Mayflies are very unusual creatures, having features that no other insects have. Unfortunately, they are very obnoxious pests and incredibly common in Virginia. Learn more about these creatures - and how to keep them at bay in your living spaces!


What Do Mayflies Look Like?

Mayflies go by a lot of different names. They are called sandflies, drakes, shadflies, dayflies, and fishflies. They also go through four different stages, starting out as eggs and ending in the adult winged form that people identify with mayflies.

As nymphs (the second stage of their cycle), mayflies are aquatic. They actually have gills at this stage and are slender with six clawed legs. It almost sounds like some weird monster from a scary movie, but they are very small- some only 2.55mm (which is 0.1 inches long). The biggest of the nymph varieties can get to 32mm, which is hardly movie-monster-sized proportions.

Usually, eggs hatch into nymphs within a few weeks but the nymphal stage can last as long as two years. While it can also happen quickly, in as little as two weeks, it usually occurs on an annual cycle.

Once they develop into adulthood, their wings will emerge and they will leave the water to rest and shed their skin for the last time. This third phase can last minutes or up to a few days. However, once that happens, mayflies will look as most people expect when hearing the word: they have opaque wings- in general, a large triangular pair and a smaller rounder pair behind. They have two or three tails that are as long or longer than their bodies, which are long, thin and brown, gray or yellow.

What Makes Mayflies So Unusual?

Everyone seems to already know that mayflies have extremely short lives. In fact, they only live for a few days once they emerge as adults. But do you know why they only live for one or two days? Once mayflies are in their final, winged form, they cannot eat. Adult mayflies don't have a functional mouth, making it impossible for them to feed.

There are a few more weird facts about mayflies you may not have known that make these creatures stand apart from other insects. Some of these you may have already learned from the previous section. Mayfly nymphs have gills, and they are the only insect to molt after having fully developed wings.

Mayflies are also unusual in that their emergence can be in such extreme numbers, it can change the smell of the air and make the ground slick. Kind of sounds like that horror film again, doesn't it? They tend to emerge throughout the summer months, though they can start as early as March here in Virginia.

How Do I Keep Mayflies Away From My Home?

You probably already guessed from their aquatic nature, mayflies need water. While the presence of mayflies is a good indicator of the health of streams and freshwater (not to mention great for fisherman), no one wants that monster emergence happening in your own backyard.

If you live near hatching areas, like rivers and freshwater lakes, you're going to have a bigger challenge keeping these creatures at bay. They are attracted to white light, so yellow exterior lightbulbs may help keep them from swarming. Keeping doors and windows closed (or at least screened) will also prevent these insects from coming into living spaces, attracted by the light.

Because of their short lives and tendency to be prolific here in Virginia, one of the most foolproof ways to keep mayflies from swarming your home and yard is to maintain a professional pest control barrier around and in your property.

Call us today for help with all your pest control needs!

To learn more about local Virginia pests, check out our Pest Library!

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