Onion fly: how to fight onion fly, photo of onion fly

Experienced gardeners will agree: it is not possible to grow a rich harvest of onions every year. And with such a “helper” as the onion fly, one can only dream of a juicy feather and a tight turnip. The onions were eaten by “some white worms,” gardeners sadly state.

The trouble is that the onion fly does its damage unnoticed. For example, everyone recognizes the Colorado potato beetle, which methodically gnaws potato leaves, and what the onion pest looks like, gardeners begin to become interested when someone suggests the probable cause of the loss of the crop. And not only onions, but also garlic!

The choice of an insect seems strange, because onions and garlic are powerful antioxidants with a pronounced phytoncidal effect. Healthy vegetables kill viruses and bacteria, but cannot cope with one pest. If there is an onion fly in your garden beds, there are two options: stop planting onions and garlic, or find out how to fight the onion fly and get rid of the harmful insect forever.

What does an onion fly look like?

Many representatives of the order Diptera are similar to each other, and you need to be an entomologist to be sure to recognize a specific species. Imagine an ordinary housefly, only smaller, about 5-7 mm long. If you want to get to know each other better, look for onion flies in the spring on dandelion or cherry flowers.

You can recognize the pest by its yellowish-gray body color and transparent wings with a bronze tint. Armed with a magnifying glass or high-quality photos of the onion fly, you will see black legs and fleecy bristles on the back.

Signs of defeat

It is extremely difficult to see the larvae of this pest in the garden with the naked eye, because most often they hide in the soil.

If an onion is damaged by this pest, it will emit an unpleasant smell of rot. If the soil near the plant is loosened, it will be especially felt.

The presence of onion fly on a plant is determined by its appearance. It is able to make its way through the husk of a plant and eat its inner part - the fleshy scales. Onion heads damaged by a fly are completely unsuitable for consumption. Initial signs of damage include:

Plants begin to rot and soften. They are lethargic and soft with a touch of rot.
Slow onion development.
The feathers of the plants will turn yellow or wither (what else can cause onions to turn yellow?). The plants themselves will emit a bad smell.

Life cycle of onion fly

Egg – larva – pupa – imago. Most dipterans undergo this development; the onion fly is no exception. The emergence and mating of adult insects coincides with the first wave of dandelion flowering. Having filled themselves with sweet nectar, females look for beds with onions and garlic, and are primarily attracted by well-grown winter seedlings.

Egg - larva

During her life, one female lays about 60 eggs in small portions. The choice of places is strictly defined: either directly on the ground near the onion and garlic plantings, or on young greens at the base of the bulb. It is difficult to notice the masonry with the naked eye. The eggs are oblong, white, no more than a millimeter, with a dark stripe along their entire length.

Larva - pupa

The larvae develop very quickly, within 2-4 days, stretch the egg shell, break through and get out. These are the same “white worms” that are found in rotten bulbs. The whitish-cream color of the larva really looks like a worm.

There are about 15 eggs in one clutch of onion fly. Fortunately, in our gardens there are birds that feed on the eggs and larvae of insects and predatory insects that eat their own kind. Some of the larvae die, but the survivors remain very friendly and immediately bite into the nearest onion.

One family of onion fly larvae can eat almost all the pulp. When one bulb becomes not enough for everyone, the larvae move to neighboring ones through the bottom. In about 2-3 weeks they eat the onion from the inside, increasing in size to 10 mm.

Larvae feeding on leeks.

Pupa – imago

At the next stage of development, the larvae leave the bulb, climb into the soil to a depth of about 20 cm and pupate. The onion fly pupa resembles a brick-colored barrel.

Onion fly pupae in root vegetables.

The insect stays in the pupal stage for up to 3 weeks, after which the adult onion fly emerges and the cycle repeats. Considering that females of the first and second generations lay eggs in portions, the larvae eat the crop all summer. Insects that did not have time to fly out before the onset of cold weather successfully overwinter in the soil or are sent for storage along with the surviving bulbs.

Where does this onion grief come from and how did hardworking gardeners deserve such a “gift”?

Reviews

Before planting onions, I always soak them in warm salted water for 3 hours - dissolve 1 tbsp in 1 liter of water. with a heap of salt. I use only coarse kitchen salt. And still, every time I pick onions for a fresh salad, they tear off the feathers and check to see if there are any worms there. Anything can happen.
Stefania, 41 years old, Bryansk

We never hope that the onion fly can be scared away by the smell of grass and flowers, and therefore we always prepare the soil in advance. In addition to kerosene, I sometimes use birch tar. If they pour trenches under onions or potatoes in the spring, there will be no onion fly or Colorado potato beetle.
Gleb, 35 years old Orekhovo-Zuevo

I am not afraid to use chemicals and always use them in my garden, not only for onions, but also for all vegetable crops. The main thing is to follow the manufacturer's instructions, not to increase the concentration of the solutions, and stop using them in a timely manner. For onions, I use the “Fly-eater” product, which is applied to the soil before planting the onions. It acts not only on fly larvae: all pests that are in the soil at this time disappear. I believe that spring prevention is much more effective than summer insect control.
Grigory, 55 years old, Tolyatti

Natalia

Author

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The hook fly, like the hoverfly and carrot fly, do not necessarily have to become a scourge that you have to fight with all summer. Pre-prepared and disinfected soil will guarantee that onion beds will not grow heads in which insects will swarm. Any stray fly will not want its offspring to be in the ground from which the pungent smell of the same kerosene emanates. It is within the power of any gardener to protect his plants from pests. Health to you and your loved ones!

Onion fly: causes of appearance

Onion flies don't have to fly far. In one garden or another, pests will find unprotected beds of onions and garlic, which they will happily take advantage of.

Since these are insects and not an infection, the damage depends on the number of larvae. In the first year, only a few bulbs are affected, and if a person is faced with the problem for the first time, he may not attach any importance to this: well, a few bulbs have rotted, no problem. And without knowing it, we continue to step on the same rake:

we do not attach importance to the quality of planting material;
We do not carry out pre-sowing treatment of seedlings;
We do not observe crop rotation;
we are too lazy to dig up the beds before frost;
We ignore basic preventive measures against pests.

The onion fly doesn’t need much; it will lay eggs once in the garden bed and the offspring, undisturbed by anyone, will continue in the same spirit. Unfortunately, many realize it when the crop loss reaches 50-70%, and the remaining 30% will probably rot in the boxes in the next month. But recognizing the “markers” of a pest is not at all difficult.

Prevention methods: how to protect plantings in the garden?

It is better to take precautions and prevent the onion fly from appearing on your plantings. To preserve your harvest, it is necessary to carry out preventive measures:

Plant onions correctly. If you sow carrots nearby, its smell can repel the pest. The onion fly will not live smelling this root crop and the likelihood of damaging the crop will be minimal. Instead of carrots, other plants with a strong smell are also suitable. For example, wild rosemary, as well as lovage or tomatoes.
Crop rotation should be carefully observed. It is not recommended to grow this crop in the same place for several years in a row. When the onion fly settles in the soil, it will remain there for the winter, and with the onset of spring it will safely begin to destroy the plantings. To interrupt reproduction, onions should not be returned to this place for 4 years.
Disinfect the planting material, as it may be infected with the pest and its larvae.
Be sure to remove affected plants away from the area. It would be better to burn them.

Signs of onion fly

Healthy onion or garlic sprouts quickly, quickly grows green mass, does not turn yellow or wither. The appearance of plants affected by onion fly larvae speaks for itself:

individual plants are noticeably lagging behind in development;
the lower feathers of the onion turn yellow and become “snotty”;
severely weakened plants wither;
those that are more resilient or less affected continue to grow and get sick, but the turnip becomes unedible, soft, slippery and smells bad.

Usually it doesn’t occur to anyone to cut and look at an onion that can’t be eaten anyway. But if you do this, an unsightly picture will open: blackened, corroded tissue and a couple or three “white worms.”

It’s unpleasant and offensive, but there’s no need to lose heart. Burn the diseased vegetables along with the pests, and grow a stunning harvest next year; fortunately, there are plenty of effective ways to get rid of onion flies.

How to get rid of it using ammonia

Ammonia is mainly purchased in pharmacies in the form of a 10% solution for inhalation. It is used both to prevent egg laying and to combat onion fly larvae. You can destroy the larva using a solution of 3 tbsp. alcohol in 10 liters of water. The root zone of onion beds is treated every 4-5 days. To repel onion flies, onion tops are sprayed every 10 days. You can use ammonia only during the first period of the onion growing season - until mid-June.

Ammonia as a fertilizer

Methods for controlling onion fly

Man has been cultivating onions for about 5 thousand years, and the onion fly did not appear yesterday. Insecticides were invented in the last century; until then, farmers fought the pest using traditional methods. Following the traditions of ancestors or choosing chemical know-how is a personal matter for each gardener.

Insecticides against onion fly

Insecticidal preparations are really good when spraying fruit trees and shrubs at the beginning of the growing season or inedible parts of plants, such as tomato or potato tops. We eat onions whole and even when we grow them for turnips, we pinch off a couple of feathers for salad. Therefore, serious drugs must be used very carefully.

Among the popular insecticides that help in the fight against onion fly, the following are worth noting:

"Creolin": an extremely toxic but effective drug with a wide spectrum of action. It is used in veterinary medicine, medicine and agriculture;
"Alatar": an insecticide that contains the well-known "Karbofos". The drug is resistant to washing off and ultraviolet radiation;
“Zemlin”: an effective remedy against various soil-dwelling pests, in parallel with the onion fly, it gets rid of garden ants and slugs;
“Fly-eater”: a universal drug for combating any soil pests;
"Aktara": a new generation Swiss insecticide against hundreds of vegetable pests, used regardless of weather conditions.

Despite their undeniable effectiveness, insecticidal agents tend to accumulate in plants and soil; their effects are detrimental to both harmful and beneficial insects and birds. By the way, the progenitor of modern insecticides, the well-known “DDT,” has endangered many species of birds. Therefore, it makes sense to use chemicals in critical cases, when the garden is literally infested with pests and gentle folk remedies no longer work.

Traditional methods of combating onion flies

The time-tested methods that our grandmothers used to drive out the onion fly are effective and safe, their use allows you to get a healthy, 100% healthy harvest.

Good old ammonia

The ammonia solution, with its specific aroma, repels many insect pests, including the onion fly. Dilute 50 ml of ammonia in 10 liters of water and pour it between the rows of onions and garlic. The composition for spraying is prepared in the same proportions. The first treatment is carried out after emergence of seedlings, then once a month. As a bonus, the soil is enriched with nitrogen and soil acidity is reduced.

Doctor, I would like a prescription for potassium permanganate...

A cheap, generic antiseptic called potassium permanganate was declared a precursor and explosive in 2007, so you'll likely need a prescription to purchase it. If there are any supplies left, you have an effective means to combat onion flies.

A weak solution of potassium permanganate is poured between the rows, preferably without getting on the feather, at the first sign of the appearance of an onion fly. It is also practiced to water with a weak solution of potassium permanganate with the addition of 1 tbsp per 10 liters. l. table salt and ammonium nitrate. Onion fly larvae will not tolerate such disinfection.

Ash and tobacco dust

These wonderful products are used for dusting beds with onions and garlic, as well as in watering solutions. Dissolve 2 cups of ash in 10 liters of water, water the rows every 2 weeks. When working with tobacco dust, take 250 g of powder, dilute it in 10 liters of water, and after 2 days sprinkle on the onions and garlic. You can buy a ready-made composition called “Tabazol”.

Tobacco dust.

Kerosene, turpentine, tar

These are real folk remedies that used to be in every village home. Our grandmothers did not think for a long time about how to deal with the onion fly, they took a bucket of water and diluted in it what was at hand: 50 ml of turpentine or 50 ml of kerosene or 20 ml of tar. They poured the prepared solution on the onion and garlic at the roots and did not know the onion's grief.

People also advise using table salt against onion flies. Salt solutions are destructive to pest larvae and beneficial soil flora, they strongly acidify the soil and in this bed, except for sorrel, it is unlikely that anything will grow.

And of course, all folk and chemical methods of combating onion flies are useless if you do not adhere to the basic rules of plant growing.

Agrotechnical measures

Check if you are following simple but effective prevention methods to protect your beds from onion flies:

You probably trust the quality of your planting material. If you choose in a store, do not take a net that contains rotten or lethargic sets;
Pre-sowing treatment of seed and nigella is mandatory. To do this, planting material is soaked for 5 minutes in hot water (55°C) or for 20 minutes in an unsaturated solution of potassium permanganate. Dry before planting;
observe crop rotation, plant onions and garlic after green manure or crops to which large doses of organic matter were added: zucchini, pumpkin, cucumbers;
Plant onions and garlic near carrots and you will protect vegetables from onion and carrot flies. It has been proven that the onion fly does not tolerate the smell of carrots, and the carrot fly will never lay eggs near onions and garlic;
mulch the plantings with rotted manure or humus, preventing females from accessing the ground;
In autumn, turn over layers of soil about 20 cm thick in the beds to prevent pupated larvae from overwintering.

Make it a rule to use time-tested methods of combating onion flies and you will be surprised how quickly you will repel the pest from the garden, and you will probably burst into tears of happiness when the spicy juice splashes from a juicy, crispy, incredibly healthy and tasty onion.

Preventing the spread of insect pests

To reduce the damage caused by larvae, follow these simple rules:

Adjust the sowing time (do not plant onions during the period of peak fly activity).
In the fall, plow the soil on the site.
Get rid of weeds in a timely manner.
Treat the seeds before planting (soak them for 5 minutes in hot water (55 0C), air dry).
Remove infected plants regularly.
Harvest well (do not leave the bulbs on the field).

Monitoring onion fly activity as a means of crop protection

To catch adult onion flies, use special traps (cone-shaped with a mesh structure). Place bait inside - damaged bulbs. This method is effective for detecting the flight activity of the pest when the plants are still young. You can use yellow sticky traps, placing them directly above the plants. Monitoring results help you choose the right spraying schedule.

Video: how to properly prepare seedlings for planting

How does plant infection occur?

The insect's flight begins in the spring during the flowering of lilacs and dandelions, and lasts about 2 weeks. This period falls on the second half of May. The female lays 40-60 eggs during her life.

Soon after emergence, the female looks for a place to lay eggs. Eggs are laid at the base of the bulb, under the first dry scales, between the leaves or on the soil near the plant. Eggs mature within 3-8 days depending on weather conditions.

The hatched larvae continue to stick together. Immediately after birth, they bite into the flesh of the bottom and feed, scraping out the fleshy scales of the young onion. The insect remains in this stage for approximately 3 weeks. Baby flies are highly voracious and are able to eat not only multiple passages inside the bulb, but also large cavities.

Having eaten their fill, the larvae go into the ground next to the damaged bulb, pupate and form in this shelter for another twenty days. During this period, they already have the rudiments of wings. And in June, the flight of the second generation of flies begins, the larvae of which damage bulbous plants of late planting dates. In the southern regions, the onion fly can have 3 generations over the summer.

Only pupae overwinter, burrowing into the ground to a depth of 5-20 cm. And in May the cycle begins anew.

Prevention of infection

At home, the most important way to combat onion flies is preventive measures:

treatment of plants before sowing;
early planting of crops;
correct change of crops in the beds;
sowing plants next to crops that repel flies;
digging up the earth in the autumn.

All of the above measures allow you to get rid of the onion fly and save the harvest. If the pest does appear, you need to react immediately, choose the appropriate means and methods of destroying the parasite.