If you grow plants you’ve heard of the Aphid pest, but what is an Aphid Midge?
What Is An Aphid Midge?
Simply put, the aphid midge (Aphidoletes aphidimyza) is a good bug and aphid predator.
The adult midge flits around your garden pollinating and looking rather fetching, but the real garden helper is in the larval stage.
Aphid midge larvae are ferocious and voracious aphid killers. In fact, a single larva can consume up to sixty-five aphids in just one day.
The larvae have strong jaws and a paralyzing toxin able capable of getting rid of the aphid population naturally.
The larvae feed and kill the aphids by grasping them firmly and then they paralyze them by injecting toxin into their leg joints so they can’t run away.
Next, they suck the aphid body contents dry, leaving behind a collapsed, blackened husk still clinging to the leaf with its useless legs.
All-in-all, aphid midge larvae are a more effective biological control option against aphids than the more familiar lacewings and ladybugs.
Their small size and homely appearance cause them to be overlooked, but they really are excellent garden helpers for insect pest control.
In this article, we discuss the aphid midge and its larvae and share advice on adding or attracting these beneficial insects to your garden. Read on to learn more.
What Does The Aphid Midge Look Like?
Mature aphid midges are tiny and these delicate flies look quite a bit like fungus gnats. They are about an eighth of an inch long, black and have long, spindly, slender legs and antennae.
When resting, they usually curl the long antennae back over the top of the head.
The larvae are also quite tiny, with a rather slug-like appearance.
The different species come in a variety of shades of yellow, orange and brown and measure about 1/10 of an inch long.
If you look closely, you will see two very tiny tubes (anal spiracles) projecting from the hind end of an aphid midge.
These larvae look exactly like apple leaf curling midge larvae, but you can tell them apart by their behavior.
True to their name, the apple leaf curling midge can be found hiding in the curled edges of apple leaves.
Additionally, these midges stay in groups. Aphid midge larvae roam about on their own hunting for prey.
Hoverfly larvae also look quite a bit like aphid midge larvae, but are larger, and always yellow.
What Is The Aphid Midge Life Cycle?
The mature aphid midge lives for several weeks and can reproduce multiple times during a single growing season.
When egg-laying, females lay 100-200 eggs per clutch.
The eggs are bright orange and shiny. You may find them in groups or laid individually.
Female midges help in aphid control by seeking out aphid colonies and laying eggs in their midst so that during the larval stage the young will have a ready food supply upon hatching.
In just two or three days, the eggs hatch and the larvae begin hunting and are attracted to the aphid honeydew.
As the larvae grow, they go through three development phases (instars) over a period of three to five days.
When they reach full size, they measure about a tenth of an inch in length.
At this size, the slug-like larvae drop to the ground and pupate under plant litter.
They create cocoons using cast-off aphid skins, excrement and bits of dirt.
The pupae inside the cocoons range in color from bright orange to dark brown. Metamorphosis takes ten days.
How Can You Attract Aphid Midges To Your Garden?
These aphid predators are naturally occurring through all of North America.
If you set up your garden to provide a habitat for good bugs, you probably already have aphid midges.
They need a water source and plants that produce plenty of nectar and pollen.
Because the tiny midges are so lightweight, they seek out settings sheltered from strong winds.
They like a humid environment and a fairly steady temperature ranging from 68° – 80° degrees Fahrenheit. They do especially well in a greenhouse setting.
How To Find Aphid Midge Eggs And Larvae
During the growing season, you should be able to find aphid midge eggs and larvae in any colony of aphids in your garden.
Look at plant stems and the undersides of leaves. They are especially prevalent on rose bushes and fruit trees. Here’s what you should look for:
The orange eggs are very tiny (0.1 – 0.3 mm) oval in shape and orange in color. You may find them singly or in small clusters.
The larvae look like tiny bright orange maggots.
The color may vary depending on the aphids’ food source.
Colors can range from pale yellow to dark red.
If you do not find them naturally occurring in your garden, don’t despair!
If you don’t think you have aphid midges in your garden, or if you want to boost your population, you can purchase them from a garden center or online.
The aphid midge cocoons usually come packaged in sand or vermiculite.
Introducing these beneficial insects to your garden is easy. Just sprinkle this mixture over the surface of the soil in the area you wish to treat.
For the most effective biological control of aphids, you’ll need to have one aphid midge larvae for every fifteen aphids (more or less).
Purchase enough of the product to have between three and ten cocoons for each plant in the area you wish to populate.
University of California overview video with a variety of aphid-eating insects, including the aphid midge.
How Can You Be Sure They’ll Thrive?
Remember, these little helpers like high relative humidity and warm atmosphere making them perfect candidates for greenhouse crops.
If you are experiencing a dry spell, water before introducing them and keep the soil watered thereafter.
Keep in mind that temperature and light are also very important.
Don’t introduce them during cold weather.
Wait until you can count on a steady temperature of about 70° degrees Fahrenheit and 16 hours of sunlight daily.
Under ideal conditions, you should see adult aphid midges emerging from their cocoons to begin laying eggs on your plants within about ten days.
Repeat the introduction of cocoons once a week for three weeks.
This will ensure that you have a booming aphid midge larvae population in place.
With the right environment and plenty of pollen, nectar and aphid colonies, the aphid midges should become well-established and return on their own year after year.
Variations in environmental conditions from one location to another can strongly affect rates of success in controlling aphids with biological controls.
You may even see your aphid midge population doing well in one part of your yard and simply failing to take hold in another.
Make careful observations and adjustments to help the little aphid predators get established.
Remember that pesticides are especially detrimental to these good bugs, and these beneficial insects are very sensitive to broad-spectrum insecticides.
Luckily, once they are established, you should have little or no need for insecticides.
What Does The Aphid Midge Control?
It is important to understand that these hungry little natural enemies are fairly non-specific when it comes to eating aphids.
Unlike many predatory creatures, the larvae don’t just kill what they need to survive. Instead, the larvae kill as many aphids as they can.
The more aphids there are, the more the larvae kill.
In addition to killing aphids, these voracious hunters also kill an impressive array of other soft-bodied insects, such as plant mites, young scale insects, psyllids, whiteflies, spider mites, and mealybugs.
Classification: Phylum Arthropoda (Arthropods) » Hexapoda (Hexapods) » Insecta (Insects) » Diptera (Flies) » Bibionomorpha (Gnats, Gall Midges, and March Flies) » Sciaroidea (Fungus Gnats and Gall Midges) » Cecidomyiidae (Gall Midges and Wood Midges) » Cecidomyiinae (Gall Midges) » Cecidomyiidi » Aphidoletes » aphidimyza (Aphid Midge)