The hoverfly, also known as Syrph, belongs to the Syrphidae family. Although it’s a fly, this species is deceptive and is confused with the wasp because of the yellow and black “belts” it wears along the length of its abdomen. But the hoverfly is not to be feared because it does not sting. On the contrary, it acts as an interesting insect to have in the garden.
Recognizing a hoverfly
The hoverfly has a size of about 1 centimeter. It has very large eyes whose position makes it possible to distinguish males from females: in the former, the eyes touch each other, which is not the case in the latter. The face is more or less yellow like the scutellum, the junction point of the single pair of wings, while its wings are transparent. The stripes closest to the head meet in the middle which makes like an H that would be lying down. Behind, the black stripes alternate with the yellow-orange ones.
One of the ways to recognize the hoverfly is the way it flies: it is both extremely fast to run away and disappear from your sight, while being able to hover as if it were an observation flight, before rushing at a flower.
Mating takes place in flight and then the females lay their eggs (up to a thousand) in aphid colonies, i.e. in the heart of a huge pantry for these larvae as soon as they emerge from the eggs.
They are headless and legless and crawl to find and ingest all kinds of aphids which they kill by injecting their toxic saliva before sucking the inside of the aphid leaving the envelope on the spot. The larval stage lasts only 10 to 15 days but during this time, the hoverfly larvae eat an average of 400 aphids and kill more than 1000 in total.
The hoverfly lives easily in flowering gardens, especially near Apiaceae, Brassicaceae, Asteraceae, during the summer season.
In addition to the hoverfly, there are more than 500 species of flies including the hoverfly of red currant (Syrphus ribesii), the sticky eristal (Eristalis tenax), the hoverfly “penholder” (Sphaerophoria scripta).
Adults gather flowers, especially shallow ones, gathered in flat umbels, with easily accessible nectar. The larvae, carnivorous, attack in particular aphids. Some species are vegetarian or consume dead organic matter.
What hoverflies eat
As the larvae feed on aphids of any species, they are essential agents in the biological fight against aphids: together with the ladybug beetle and the chrysope, the hoverfly is a perfect aphid trio!
Adults feed on honeydew and nectar, making them important pollinators.
Should you eliminate the hoverfly?
The carnivorous species are excellent auxiliaries to stop an aphid outbreak. When prey is abundant, the larva, which resembles a maggot without eyes or legs, with a tapered body at the front, kills many more than it consumes. An older larva can kill more than a hundred aphids a day.
For all these reasons, it is advisable to protect and promote the presence of girdled hoverflies in the garden. There is nothing better than to make your garden bloom by sowing rows of flowers (marigold, phacelia…) which make a good companion with the surrounding vegetables in the heart of your vegetable garden. As the hoverflies also need bark, there must be trees nearby, and then, if you can, let some umbelliferous flowers bloom (carrots, chervil parsley, dill …) which the hoverflies are fond of.
Beware, birds and bats are its main predators.
How to get rid of hoverflies?
Despite the benefits of this small insect, if you want to get rid of the hoverfly on your land, here are some tips that should help you:
1 – Setup a fan
If the hoverflies visit you indoors or in your patio, you can install a fan close to your plants, they don’t like to be disturbed at all and will soon find another quieter home.
However, you will have to be persistent to get rid of this harmless little insect, you will have to leave your fan on probably all day long. Finally, if the hoverflies reappear, all you have to do is re-install your fan.
2 – Prepare a natural repellent
There is a significant amount of repellent on the market, the problem is that these are, most of the time, chemical, and therefore harmful to your pets (dog, cat, birds, hamster…) as well as to nature! Indeed, there is nothing worse than a chemical liquid for your plants, especially if they are plants that you eat afterwards! Here are some natural mixtures to make your own natural repellent from home in a few minutes:
The bottle trap
Take an empty bottle and pour a syrup or beer base into it.
Hoverflies will be attracted by the sugar and will enter it, but will not be able to leave it afterwards. Empty your bottle every day and don’t forget to change the bait.
The cider vinegar recipe
Fill a small bowl with cider vinegar, then add a few drops of dishwashing liquid and mix.
Place this bowl in the middle of your kitchen and wait for drosophila to get trapped in it. Change it every day.
They can be very useful to fight against the invasion of midges by acting as a natural repellent.
This is the case of the following essential oils:
– Tea tree
You never know what to do with your corks? Throw them away? What an idea! Hoverflies hate the smell of cork: if they congregate near your fruit baskets, put your cork stoppers inside and you’ll be surprised to see no more frolicking around.
The black soap
Black soap is also very effective against flies and midges that nest on your houseplants. The method consists of diluting one tablespoon of liquid black soap in one liter of warm water and then adding one teaspoon of baking soda. After mixing, take a spray bottle, sprinkle the liquid on your plants and say goodbye to flying insects.
A little-known natural anti-aphid: dishwashing liquid
Desperate and nothing to fight aphids? Spray some dishwashing liquid directly on the aphids! Use an ecological product, which will not damage your plants or the soil, or do it yourself.
Repellent spray with eucalyptus
In 5 liters of water, place 150g of fresh eucalyptus leaves. Boil the whole for 15 minutes, before letting the mixture rest so that it cools down.
Once the mixture has cooled, filter the decoction and pour it into a spray bottle. Spray this solution several times a day to kill midges.
Citronella oil or candles is also a good natural repellent against gnats in general and hoverflies in particular, the smoke and the smell that comes out of it will quickly make them change their minds!
3 – Making a hoverflies trap
The classic method, Cider, vinegar and wine/beer:
Cider, vinegar, white wine or beer – simple but effective, cover a fairly deep jar filled with one of these substances with transparent film and make a few tiny holes with a knife or needle. This will allow the hoverflies to enter the jar but prevent them from coming out.
Vinegar and washing-up liquid – add a few drops of washing-up liquid to a vinegar base. The dishwashing liquid breaks the surface tension on the surface so that the midges, attracted by the liquid, drown in it.
Vinegar paper funnel:
A paper cone in a glass – Another effective trap is to make a paper cone with a very narrow hole at the end. Place the end down in a glass or jar with a little white vinegar and a piece of ripe fruit at the bottom. The cone should stick to the sides of the jar. Hoverflies will crawl inside and get trapped.
Milk, sugar and pepper – home recipe with a glass of milk, 100 grams of brown sugar and 50 grams of pepper. Simmer the mixture in a saucepan for 10 minutes and pour it into a soup plate. The delicious mixture will attract them, and they will drown in it.
4 – Giving the hoverflies what they want
Adults, feeding on nectar, may be attracted near crops. Despite the fact that they can be annoying, the best thing to do is to protect them by sowing flowering strips of green manure, especially between fruit trees, or by letting certain vegetables or aromatic plants of the Apiaceae family (carrot, celery, fennel, parsley, chervil …) bloom.
Favouring natural enemy auxiliaries of crop pests is both a way to make room for biodiversity and to think differently about our fruit and vegetable production. The technique is not new, but it is becoming more effective as new experiences are gained and as more people and professionals use it.
Most hoverflies larvae are carnivorous, but a few eat plants without causing any particular damage, as their appetite is limited. This is not the case for the larvae, which are much more numerous in hoverflies, which hunt their prey for food.
If the hoverflies were one of the first species to be used in the biological fight it is not for nothing. Indeed the larvae crawl up to their prey, often aphids, to bite them and suck the inside of the unfortunate ones. But the larvae do not go into detail and can kill more than they consume, unable to curb their hunting instinct.
A larva at the peak of its glory can kill up to 100 insects a day, placing it high on the podium of the gardener’s and farmer’s allies. During its development, a larva can devour
In any case, the primary objective is to bring the future larvae as close as possible to their snack, be it aphids, mites or others. It is therefore necessary that the plants that host aphids are on site all year round, such as black elderberry, stinging nettle or mullein, to name but a few.
Then it is also necessary to provide for the needs of the adults by satisfying their appetite for pollen and nectar… Throughout the season! It will then be a question of making flowered strips which will go from very early flowers to very late flowers. The Veronique, the Corniculated Lotus (very good in infusion), the Marigold, the Thistle and many others will have the favor of the Syrphes.