Why Do Hoverflies Hover? And How Do They Do It?

folder_openDiptera, Insecta
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Aerodynamically bumblebees aren’t supposed to fly, but they do it anyway. Hoverflies do something even more amazing: they hover! But why do hoverflies hover, and how do they do it? We explore the science behind insect flight in this article.

It is quite rare to come across phenomena that break the laws of science.

The flight of the hoverfly is one such case that defies the conventional laws of aerodynamics that holds true to flights, helicopters, and more.

How? Let us find out.

 

Why Do Hoverflies Hover

 

How Many Types of Hover Flies Are There?

Flower fly populations are abundant worldwide. You will be fascinated to know that there are approximately 6,000 species of hoverflies globally.

They can adapt well to various climatic conditions, which is why you can find them in all regions except Antarctica and deserts.

Also, 62 hoverfly species are found in America. You can spot them in Ohio, Pennsylvania, Kentucky, West Virginia, and many other states in the US.

Adult hover flies prefer to be around flowering gardens as they are the ideal sites to provide primary food sources like nectar and pollens.

They like to lay their eggs in places that are infested with aphids, so if you have both things in your garden, then it is likely that you will find hoverflies.

Do All Species Hover?

Almost all hoverfly species can be spotted actively hovering over a wide range of flowers.

Since they are active flower visitors, they are often considered excellent pollinators.

Also, the hover fly larvae are ferocious predators of aphids, scale insects, and other soft-bodied arthropods.

Due to this, farmers use these bugs for biological control of aphid infestations. A bunch of larvae can comfortably eradicate entire aphid colonies in days.

No wonder why they are called beneficial insects.

 

Hornet Hoverfly

 

Why Do Some of Them Hover?

Hoverflies get their name because of their ability to stay suspended in the air during flight, like a drone. But not all of them hover.

There is a particular species of hoverfly that are called drone flies.

A drone fly is an excellent mimic of a Honeybee. They, too, have bee-like black and yellow stripes on the abdomen.

These drone flies hover around the flowers to be able to feed efficiently.

However, hovering also helps them attract mates.

Research has shown that the stability and duration of the hovering help to attract the female. The more steady they are in mid-air, the more the chances of impressing a mate.

Also, these insects will keep hovering around you if you are drenched in sweat.

This happens because hoverflies are particularly attracted to the salts in human sweat and fall on the skin to lick them.

How Do Hoverflies Fly?

The hovering ability of hoverflies is one of the most interesting facts about them.

These flies constantly keep adjusting the frequency of their wingbeats to the wind pattern to stay afloat during windy days. How amazing is that?

A strong gust of wind cannot blow away a skilled hoverfly.

On rare occasions, you can also spot them around flowers flying backward.

 

Hover Fly

 

Flexible Wings

The primary reason behind this is the flexible pair of wings. Hoverflies have one of the most flexible wings in the insect kingdom.

The versatile nature of their pairs of wings is off the charts; they can bend and twist these wings at a 45 degrees angle and at a frequency of 300 Hz.

These wings help to maintain the perfect angle to be able to hover.

Leading Edge Vortex

According to the laws of conventional aerodynamics, insects like bumblebees and hoverflies are not supposed to be able to fly.

The leading edge vortex is a process that allows these insects to fly. It is this process that helps these insects to defy the laws of aerodynamics.

As the name suggests, a vortex is created along the leading edge of their wings; This creates a low-pressure zone on top of the wings.

As per Bernoulli’s theorem, the low-pressure zone adds an upward lift that helps them fly.

Air Viscosity

Another reason insects like bumblebees and hoverflies can fly is because of the viscosity in the air.

Viscosity adds resistance when these insects beat their wings.

The dragging action involved sweeps more air which results in higher resistance.

The additional resistance gives a stronger push to support the weight of the insects.

 

Footballer

 

These observations were made by John Maynard Smith and M.J. Davies in the 1950s.

This was done through an experiment where they etherized a few hoverflies and pasted them on a pin.

Later they surrounded them with metaldehyde particles and conducted flash photography to record the length of exposure.

The resulting pictures were quite underwhelming according to modern standards but strong enough to record the above observations.

Frequently Asked Questions

What are hoverflies attracted to?

Hoverflies are attracted to any area that has an abundance of flowering plants.
They hover around these flowers to mate and consume pollens and nectar.
Also, in the initial life stages as larvae, they love to be around aphid populations as they are the primary food source.
You can attract them to your garden by having bright-colored flowers nearby.

Why do Hoverflies hover around you?

Hoverflies are especially attracted to the salts present in human sweat.
If you are drenched in sweat, hoverflies will hover around you to lick and consume the sweat beads.
To avoid this, use sweat repellents that will keep you dry on hot sunny afternoons.

What is the purpose of a hoverfly?

In an earlier stage of the life cycle as larvae, these insects consume aphids, scale insects, and more to attain enough nutrition to transition into the pupal stage.
Once they grow up, they fall and hover around flowers to consume nectar and pollens and to find mates.

Where do hoverflies go at night?

Various species of flies and insects are usually attracted to bright lights at night. Once they spot a light source, they start flying toward it.
Also, some insects search for a safe spot to rest after the sun goes down. You can find them on twigs, branches, and on the undersides of leaves at night.

Wrap Up

Technically insects like bees and hoverflies should not be able to fly.

The experiments conducted by John Maynard Smith and M.J. Davies in the 1950s explained how these insects could fly despite the laws of physics being stacked against them.

We hope the article helped you get some insight into the amazing capability of flight that these insects possess.

Thank you for reading!

 



 

 

 

Hover Flies Aerial Mating

 

 

Hover Fly

 

 

Bee/Fly with Yellow Striped Eyes? March 30, 2010 Saw this on the patio a couple days ago. Thought it was a bee at first, but the yellow striped eyes were pronounced. It’s about the size of a common bee or fly. Do you have any idea what this might be or what would cause the markings on the eyes? Kyle B. Long Beach, California

 

 

 

Syrphid Fly, we believe

 

 

 

 

Authors

  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

    View all posts
  • Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

    View all posts
Tags: Hoverflies

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