Did you ever notice the Hoverfly in your garden? Those tiny, yellow and black flying insects in your garden.
When first observing these beneficial insects many wonder if they are honeybees, wasps or some other type of stinging insect.
Chances are, your striped visitors are none of these. They are probably hoverflies, an industrious beneficial insect that can do your garden a lot of good.
In this article, we describe hoverflies and explain why they are so helpful and how you can attract them to your yard and garden. Read on to learn more.
Hoverfly Quick Facts
Overview: Beneficial insects, excellent weapon to battle aphids. One larva during development can consume 400 aphids
Common Name: Syrphid fly, Drone fly
Location: Numerous Hoverfly species “work” throughout North America
Benefits: Adults are excellent pollinators, larvae feed on aphids, thrips and scale insects
Attracting: Plant nectar and pollen producing plants, wild weeds like yarrow.
What Are Hover Flies & What Do They Look Like?
Hoverflies are small, bee-like flies that may be found in abundance in wildflower fields, flower gardens, and orchards.
They are members of the insect family Syrphidae, and you will sometimes hear them referred to as syrphid flies or a drone fly (Eristalis tenax).
There are many species of hoverfly within this group, but hoverflies are the only ones whose coloring and markings mimic wasps and bees.
Most are yellow and black like wasps and bees, but some can have orange or brown markings. Still, others may have glints of metallic green mixed into the black areas.
Why Do They Have This Color Pattern?
Most likely, it is an evolutionary development that allows them to go about their business unmolested by would-be predators.
After all, if you have a hard time determining whether or not these harmless little flies are stinging insects, it’s likely that predaceous insects, birds, and reptiles experience the same confusion.
Just to be clear, hoverflies do not sting or bite and are not at all dangerous.
You should be able to distinguish them from bees and wasps by their non-aggressive, purposeful behavior.
Are Hoverflies Beneficial To The Garden?
Their benefits to your garden are twofold.
Adult Hoverflies are important pollinators and the larvae are robust killers of aphids, thrips and scale insects.
Observing the flies’ pollinating behavior is one way to tell syrphid flies apart from wasps and bees.
While wasps and bees zip from flower-to-flower, hoverflies hover effortlessly – hence the name.
It’s easy to see syrphid flies hovering about the garden.
One upside of this behavior is that it makes for great photo ops, as shown in this hoverfly gallery!
How Many Wings Does A Hoverfly Have?
Another way you can tell whether an insect is a wasp, bee or hoverfly is to count its wings.
Bees and wasps have two sets of wings. Hoverflies are true flies and have only one pair of wings. Of course, getting close enough to any insect to count its wings could prove problematic.
Your best course of action when encountering just about any insect is to believe that if you leave it alone, it will leave you alone. The vast majority of the time, this is true.
Are Hoverflies The Same As Sweat Bees?
These beneficial insects share the nickname, sweat bee, with an actual bee, which is a member of the very large insect family called Halictidae.
Both types of insect-like to hang around sweaty people for a drink of sweat in hot weather.
Although this is disgusting to us, for these insects, sweat is a good source of electrolytes
If you encounter insects exhibiting this behavior, just follow the general rule of thumb when any insect is buzzing you and bothering you.
Try not to panic. Don’t wave your arms around and scream. Just move off in a purposeful manner and get a wall between you and the insects.
Hoverflies and sweat bees are merely pesky but not aggressive.
If a yellow and black striped insect is aggressive and persistent, it is probably a yellow jacket.
You’ll recognize it because yellow jackets are quite a bit larger than hoverflies and sweat bees, and they have pointy heads.
Even if your pestering insect is a yellow jacket, don’t panic or swat, just move away to a safe place.
What Do Hoverflies Do?
For the most part, you can expect hoverflies to mind their own business, which is pollinating and producing voracious, aphid-eating larvae.
The hoverfly earned its common name from their unique ability to dart short distances and hover, in mid-air and quickly dart and hover again.
The adult flies do not eat pest insects, but their larvae are some of the very best aphid killers in the insect world.
They aren’t much to look at with their typical maggoty appearance, but they aggressively consume vast quantities of aphids.
In the span of time between their hatching and metamorphosing into a fly, each of these little maggots consume about 400 hundred aphids, as well as other soft-bodied insects such as thrips and scale insects.
You’ll typically find the hoverfly larvae advantageously positioned in midst of aphid congregations, busily munching away.
The larvae make very short work of infestations of aphids, scale insects and thrips.
They are only second to ladybugs in their ability to wipe out great numbers of these little devils.
One reason these maggots are such effective aphid predators is that they are more cold hardy than other types of aphid killers.
This is why they are so valuable to growers of peaches (and other types of stone fruit) as well as apples.
In fact, green peach aphids are a favored food for hoverfly larvae.
They do well in the cooler conditions found in successful peach orchards.
To determine whether you have hoverfly larvae in your garden, look for oily, black smears of excrement on plant leaves near aphid colonies.
Of course, if you can see aphids, you will also see syrphid fly larvae if they are present.
What Are The Life Stages Of The Hover Fly?
#1 – Eggs
Eggs are about the size, shape and color of a grain of rice. Female hoverflies lay the eggs individually. They are careful to place them close to, or within aphid colonies.
#2 – Larvae
The larvae are sightless and legless and basically shaped like a maggot. They are a creamy yellow in color and have a pointy head and rounded rear end.
There are two dark breathing tubes located at the tail end. Their mouths are equipped with three sharp points for piercing and holding aphids as they suck them dry.
#3 – Adult Flies
The grown flies look a little like bees and wasps because of their coloration, but their bodies are flatter, and smaller. They typically measure no more than a half inch in length.
Most hoverflies are yellow and black, but some have a little metallic green glint incorporated in the black stripes. Some are orange and black.
How Long Do Hoverflies Live?
In cooler climates, these flies typically produce about three generations annually. In warmer climates, they can produce many more generations.
Don’t expect to see hover flies after the first frost.
They settle in and reproduce especially well in settings with lots of pollen and nectar-producing flowers and weeds.
Adults feed on these plants as a food source and a good place for females to lay eggs.
Hoverflies typically start out the growing season amidst ground growing plants. Later in the spring, they may move to blossoming trees to eat pollen and nectar from the flowers.
The adults will also consume the honeydew produced by scale insects and aphids. They lay their eggs in colonies of these pests.
When the hoverfly maggots emerge from the eggs, they begin gobbling up aphids, thrips and scale insects immediately.
Even though they have no legs and cannot see, they move about swiftly and seem to have no trouble finding soft-bodied insect pests to eat. They are enthusiastic eaters and frequently lift their prey aloft while sucking them dry, as seen in this video.
Some types of hoverflies can overwinter as adults, but most die in the winter.
The larvae overwinter on the ground, buried in leaf litter; however, winter is not the only time syrphid larvae burrow into leaf litter.
When they have reached full growth at any time throughout the growing season, they move to the ground where they will hide in leaf litter, become pupae and metamorphose into mature flies.
The entire life cycle can be completed in as little as two weeks but may extend to a full month.
Temperature, weather, and availability of food may influence the amount of time needed for completion.
Where Do Hoverfly Live At?
Because there are so many different kinds of hoverflies, there are also lots of places where you will find hoverfly larvae.
Most larvae live on leaves and stems of plants. When they pupate, you may find them stuck to plants or buried in leaf litter.
Some types live in decaying vegetation or stagnant water. The ones that live in water (Eristalis) feed on detritus rather than on soft-bodied insects.
They are called “rat-tailed maggots” (drone fly – Eristalis tenax) because their breathing siphon is long and whip-like.
The larvae of the genus Volucella call some bumblebee nests home. Microdon larvae members are found living in termite nests or ant mounds.
What Are Hoverflies Attracted To?
These flies are attracted to pollen, nectar, human sweat and aphid honeydew.
A garden that is filled with flowers, has a bit of leaf litter on the ground and provides a good water source is very attractive to syrphid flies.
What Plants Attract Hover Flies?
To keep hoverflies happy, plant lots of yellow or white flowers that produce plenty of easy-to-reach nectar and pollen. Favorites include:
- Sweet Alyssum
- Cosmos flowers
- Zinnia flowers
- Aster (hardy, aromatic)
These provide food and good egg-laying locations. Your goal is to have continuous blooming, so plant strategically so that you will have blossoms throughout the growing season.
The adult flies are the most active during the warmest months. They need plenty of blossoms for nourishment and for mating and laying eggs.
How To Use Hoverflies In The Garden
There is really not much to instructions for using hoverflies in your garden or orchard. If you build it, they will come.
Plant plenty of wildflowers, garden flowers and flowering bushes to attract the adults.
Be sure to welcome beneficial syrphid flies and their hungry, hungry young by avoiding use of insecticides or pesticides (even insecticidal soaps) to deal with garden pests, as hoverfly larvae are very sensitive to all of these.
These friendly little flies provide excellent biological control for quite a few common garden pests.
They add to the vibrancy of your garden by helping with pollination (such as Lampetia equestris or Eumerus tuberculatus) and by simply keeping the air alive with their activity.