This small insect is the most common pest of onions and garlic, and it is not so easy to notice. Therefore, every gardener should be aware of what the onion fly looks like and what means are needed to successfully combat it.
The adult insect is safe for plants because it feeds on nectar and pollen of wild plants. But onion fly larvae are by no means so harmless. The female lays eggs on the leaves of onion and garlic, in the soil next to it, and each individual is capable of producing from 40 to 60 eggs. The development of the egg, depending on weather conditions, lasts from 3 to 8 days, and then the larvae appear, which manage to destroy the entire bulb in the 12-20 days allotted to them. After the larva pupates, the next generation of flies will fly out, and everything will repeat again. In the middle zone, two flights of onion flies occur during the summer.
Description of the pest
The body of the insect is 6–10 mm long and gray with a greenish tint on the back. The pest has black legs and transparent wings.
On the abdomen of males, unlike females, there is a dark longitudinal stripe. Their eyes are located close together, and in females they are separated by the forehead.
The body of the larvae is white, cylindrical, up to 10 mm long. The larva has no distinct head and no legs. The body is narrowed towards the anterior end; a black mouth opening is located here. The abdomen is sloping at the back, and 16 conical tubercles are visible on the anal area. The larvae retain these tubercles when they develop into shiny red-brown pupae (puparia).
The pest lays white eggs, 1–2 mm in size, pointed at one end and blunt at the other.
No. 10. Naphthalene
The smell of this substance successfully repels the fly family from onion plantings. In addition, it is quite durable.
Mothballs are ground to powder and mixed with sand (8-10 stinky peas per half bucket). The composition is scattered over the onion plantation. The operation is repeated every 7-10 days during the stage of active reproduction of the pest.
To increase the processing efficiency, wood ash is used instead of sand. The mixture is prepared at the rate of one part crumbled naphthalene to 10 parts ash.
Life cycle
The full development cycle lasts 45–80 days and goes through 4 stages: egg, larva, pupa, imago (adult). The pest appears in late April - mid-May during the flowering of lilac and cherry trees. At this time, the bow already has 2-3 feathers. Mating occurs immediately after departure and within a week the females lay their first eggs.
On lumps of earth, around the base of leaves or under dry scales of bulbs, they leave heaps of 5–20 eggs for 2 weeks. Females are fertile, capable of laying 60–200 eggs . The embryo in the egg develops in 3–8 days. The emerging larvae are voracious and quickly bore into the bulbs. In search of food they can move from one plant to another.
The pest remains in the larval phase for 15–20 days. During this time, 4–5 molts occur. As the larvae grow, the upper skin does not stretch much, so the pest sheds it several times.
The time intervals between molts are called instars, each of them lasts 3–4 days. Immediately after molting, the larva's body is tender and vulnerable. The development of larvae is affected by air temperature. The higher it is, the faster this process occurs.
After the last molt, the larvae enter the pupal stage. This is the transitional stage of a larva into an adult insect. Pupation occurs in the ground under plants at a depth of 3–7 cm. The pupae are motionless, but a serious restructuring is taking place in their body.
After 2–3 weeks, the fully formed adult fly breaks through the cocoon, comes out and spreads its wings. He does not leave his place immediately, but as soon as his body gets stronger. Second generation onion flies appear in July . Adults live 12–30 days; to lay eggs, females gain strength from the nectar of flowers.
The pest overwinters in the pupal stage in the ground at a depth of 10–20 cm. Depending on the climatic region, 1–3 generations of insects appear in just one season .
No. 6. Table salt
Highly salted water is destructive for voracious worm-like larvae. But it also provokes salinization of the soil, which makes it unsuitable for gardening.
So it is recommended to carry out such processing no more than once per season.
Dilute 200-300 grams (a glass) of salt in 10 liters of water and water the moist soil in the garden bed when the feather grows to 8-10 centimeters. After 3-4 hours, water with clean water to wash off the remaining salt from the leaves.
Instead of water procedures, you can add a mixture of soda and salt (1:2) to the garlic and onions 1-2 times during the summer.
Signs of onion infection
Onion fly larvae
The most dangerous thing for plants ; they do the most damage. They penetrate into the pulp of the bulb through the base of the leaves or from the bottom. They gnaw out large areas, forming passages .
In onions, larvae from one oviposition usually feed on one bulb; in onion sets, they move to neighboring ones and eat away large cavities in the head. With a severe infection, more than 50 larvae can colonize the bulb. The larvae of the first generation destroy early varieties in June, the second - plants in July-August.
In the garden, at the first sign, it is noticeable that the plants are targeted. The feathers of such an onion turn yellow, wither and fold in half, and then dry out . If the plant is pulled out of the ground, you will see that the bulb has softened, is covered with a coating of mold, and the bottom is occupied by small white worms . Damage allows fungal infections to enter the tissue. Infected bulbs rot, and in wet weather this happens faster and smells unpleasant.
In addition to onions, the pest colonizes garlic if it is grown continuously for several years in the same place. The onion fly damages tulip bulbs , as well as carnations, delphiniums, and phlox .
Using store-bought insecticides
If home remedies are powerless against the insidious pest, you need to use one of the chemicals that are freely sold in stores. These chemicals are sold in tablet, liquid, or powder form. Before use, they should be dissolved in raw water strictly according to the instructions on the package.
The following drugs have gained the most popularity against onion flies:
- Aktara, Muhoed;
- Tabazol, Karate Zenon;
- Medvetoks, Sochva;
- Intavir, Zemlin;
- Diazinon, Immunophytophyte;
- Bazudin, Creolin;
- Spark, Alatar;
- Moveton Nova.
Using such insecticides, you can completely destroy onion flies and their larvae in a short time.
Reasons for the appearance of the pest on the site
The onion fly prefers loam and sandy loam soils, and is less common on peat bogs. Loves beds fertilized with fresh manure.
The pest settles in areas where onions and garlic have been continuously grown for many years. The problem is aggravated by the lack of autumn tillage. Since the pupae remain in the ground for the winter, pre-winter deep digging will help destroy some of the larvae that are on the soil surface.
The number of pests is affected by weather conditions. With sharp spring warming, the activity of onion flour increases. In a wet, cold spring, the harmfulness is reduced, since adult individuals appear later, egg laying and the appearance of larvae are delayed.
The pest may appear on the site when planting onion sets that are infected or not pre-treated.
No. 12. Ammonia
Ammonia is a popular pharmaceutical drug that gardeners respect as a fertilizer and pest repellent.
It drives away onion flies from the beds with a sharp, strong odor. The fight begins with the emergence of the first spring generation, and continues at intervals of 10-12 days. Pour 3 tablespoons of an odorous substance into 10 liters of water.
Due to the fact that the solution also provides nitrogen fertilizing, treatments are completed no later than mid-June.
A more advanced composition is also prepared based on ammonia: a tablespoon of ammonia, 2-3 drops of iodine, a gram of potassium permanganate and boric acid per 10 liters of water. Such a multi-component mixture will not only repel the fly, but will also destroy part of its voracious offspring.
How to get rid of onion fly
Chemical and biological drugs
Strong chemicals will be needed when the pest appears en masse and over large areas. The onion fly damages plants both in open ground and in greenhouses. If you notice it in time, you can do without chemicals or immediately destroy the affected specimens.
In the larval phase, chemicals penetrate well into the delicate skin of the pest. At this stage, contact treatments will be effective. But processed vegetables are only suitable for eating after 2–3 weeks. It is not recommended to spray onion feathers with chemicals.
Aktara VDG
Plants are sprayed against onion flies with a solution prepared from 4 g of the drug and 10 liters of water. The granules are dissolved in warm water (temperature should not be lower than 25°C).
This volume is designed to process 10 square meters. m. The onions are sprayed for the first time when the dandelions begin to bloom, and after 1–1.5 months the plants are sprayed again.
Alatar CE
The dosage of the drug for pest control is 5 ml per 4 liters of water. The beds with onions and garlic are processed in the morning or evening in dry weather no more than 2 times per season.
Corado
Systemic drug for the destruction of adult onion flies and their larvae. Does not lose its properties in dry hot weather and is not washed off by rain.
The onions are processed for the first time before planting. The seedlings are sprayed with a solution prepared from 15 ml of the drug and 0.2 liters of water. This volume is consumed for 10 kg of sets.
The onion is sprayed a second time when 3-4 feathers grow. The concentration of the drug is 2 ml per 2 liters of water. The solution consumption is 1 liter per 1 hundred square meters.
Summer resident
Biological preparation from Siberian fir extract. Harmless to humans, animals, bees, does not pollute the soil. It is used for spraying.
5 ml of the product is diluted in 8 liters of water. The solution does not lose its properties in cool and rainy weather. But a one-time treatment will not give results. Onions will need to be sprayed at least 3 times.
ExtraFlor
A preparation based on tobacco extract to protect plants from many insect pests, including onion flies. Helps to grow environmentally friendly and healthy vegetables. The contents of the package (1 g) are poured into 1 liter of warm water, mixed and the liquid is allowed to cool. Before use, the solution is filtered.
Fly eater
Diazinon-based insecticide for killing adult flies and their larvae in the soil. For pest control, it is used once before planting onions.
In calm, dry weather, granules are scattered over the soil surface at the rate of 50 g per 10 square meters. m. Then the beds are loosened. Pests die within 2–3 days after the drug enters their body. The protective effect lasts 2 months.
Zemlin
Preparation for soil application. It is scattered over the top layer and at the same time loosened the ground. The consumption rate of the product is 3 g per 1 sq. m. It protects against onion flies for 20 days.
Sochva J
The drug repels the onion fly and does not allow it to settle in the treated area. It is produced in liquid form, it is a concentrate of wood smoke. When using a concentrate, plants are less damaged - by 50%-90%.
5 ml of the drug is mixed with 1.5 liters of water and sprayed onion feathers 2-3 times. The break between treatments is 7 days. The consumption rate of the working solution is 5 liters per 1 sq.m.
Traditional methods
- Onion flies, which appear in the spring, are inactive, fly slowly and sometimes get indoors. If the planting area is small, they can be easily caught by hand or with a net.
- The onion fly is sensitive to odors. To protect plants, solutions are prepared from fragrant herbs, ash, and ammonia. These methods will be effective if applied systematically and immediately after planting the onions.
- Tobacco in its pure form or mixed with ash and ground pepper is scattered along the rows (1–2 kg per 10 sq. m.), and then the soil is loosened. Solutions for spraying are prepared from tomato tops, wormwood, and chamomile. You can place the chopped stems of these plants in the rows. After a week, the wilted tops are replaced with fresh ones.
- The insect cannot stand the smell of tar. Before planting, the bulbs are soaked for 2 hours in a tar solution: 10 g are dissolved in 1 liter of water. The tar smell when spraying onion leaves will repel insects. The crop is treated during the egg laying period. The solution is prepared from 20 g of tar and 10 liters of water. The procedure is carried out 2-3 times with a break of 10-14 days.
- Water the damp soil with a solution of ammonia. 1–2 tbsp. l mixed with 10 l of water. The nitrogen contained in the solution will feed weakened plants and prevent yellowing of the feather tips.
- An old way to combat the pest is to water the soil with saline solution. 200 g of table salt are dissolved in 10 liters of water. The solution is used only on moistened beds. After treatment, they are watered again with clean water. The saline solution is used once per season. They cannot constantly cultivate the soil, otherwise salinization cannot be avoided.
No. 4. Tobacco
The smell of tobacco reliably repels flying parasites from onion plantings. The space around the plants is dusted with the substance at the rate of a tablespoon per square meter. The operation must be carried out on damp soil, followed by surface loosening.
Advice. If there is not enough tobacco, you can combine it with lime or river sand in a 1:1 ratio. More effective additives are mothballs and hot pepper (also 1:1).
Tobacco infusion is also very helpful in repelling flies. Take 200-250 grams of tobacco crumbs per 10-liter bucket of water, leave for 2 days, filter, add soap and generously spray onion foliage. About a liter of this infusion is consumed per square meter.
The frequency of use of the infusion and powder is at least once every 7-10 days.
It is known that nicotine is released only in an alkaline environment. Therefore, it is important to properly prepare the repellent solution:
Is it true that the onion fly does not like the smell of carrots, but onions repel the carrot fly?
Planting these vegetables together repels pests. The onion fly does not like the smell of carrots, and onion phytoncides repel the carrot fly. When planting together, you need to take into account that onions ripen earlier and 2 weeks before harvesting they stop watering them so that the bulbs ripen in dry soil. Carrots still need a lot of moisture at this time. Therefore, it is better to plant crops without alternating rows, but by dividing the bed lengthwise into 2 parts . On one side, onions are planted, and on the other, carrots.
No. 2. Potassium permanganate
Some gardeners believe that potassium permanganate is fatal not only to pathogens, but also to the brood of various pests.
To prevent the onion fly from multiplying, they water the onion plantings with a solution of manganese (a teaspoon per 8-10 liters) three times. The first time at the time of disembarkation, then at intervals of 7-10 days.
But I note that the solution will only work in high concentration . This will cause the death of many beneficial soil inhabitants and also damage plant roots. Therefore, I personally do not use this product.
Prevention
- Maintaining crop rotation. The onion is returned to its original place no earlier than after 3 years.
- Planting and sowing early so that the onion has time to get stronger by the time the insect flies. The planting material is pre-etched. To speed up the growth of the heads, at the end of May the plants are fed with urea.
- The soil around the crops is mulched with compost, peat or a mixture of them with crushed coniferous or pine litter. Loose soil makes it more difficult for insects to lay eggs.
- At the first sign of a pest, infected bulbs are pulled out and destroyed.
- In autumn, plant debris is removed from the site, and the soil is dug up deeply.
These measures will not give the pest the opportunity to take over the site and will help to grow onions healthy and without losses.
More details: you will learn how to deal with onion flies from the video.
No. 9. Soap
Typically, liquid or solid laundry soap is used. For 10 liters you need to add 30-50 grams of grated bar or liquid version.
The product is applied not only to the onion feather, but also to the ground around the plants. During the season, 3-4 treatments are done with a week gap between them.
Advice. To prepare a soap solution, soft water - filtered or rain - is better suited.
What to do if they appear in the apartment
To get rid of onion midges, you first need to find places where they feed and actively reproduce.
Important! The main principle of the fight is to leave insects without food and a favorable environment for their reproduction.
To do this you need:
- review and discard spoiled bulbs;
- put the stored onions in the vegetable compartment of the refrigerator;
- If there is a large quantity of onions, store them in well-ventilated nets;
- do not leave vegetables, fruits, berries, citrus fruits on the table unnecessarily;
- throw out garbage on time: midges flock to the smell of food waste;
- do not leave dirty dishes in the sink, especially cups containing fruit juice;
- block access of insects to water: wipe sinks, do not leave dishes with water uncovered;
- use disinfectants to clean siphons, drain pipes, and sewers;
- Monitor the cleanliness of pet food bowls, remove excess food in a timely manner, and clean cages.
- review and hermetically seal containers with cereals and flour;
- If midges are found in flower pots, reduce watering and replace the top layer of soil.
Application of organic and mineral fertilizers
We have already talked about the beneficial properties of wood ash. It is used not only for preventive purposes to repel pests, but is also a good potassium fertilizer. So the use of ash is beneficial and useful in all respects.
In addition, it is advisable to use rotted manure; its smell also repels onion flies. To achieve a 100% effect, it is advisable to mix manure with tobacco dust and ash. You can also diversify this mixture with ground red pepper, then the effectiveness will be even greater.
The use of fertilizers containing nitrogen also has a beneficial effect on reducing the number of pests. To do this, onion beds are fertilized with ammonium carbonate salt. In addition to the repellent effect inherent in this fertilizer, the onion beds are recharged with nitrogen.
The onion fly is a real disaster for vegetable growers. In order to avoid this problem during the summer, the fight against it should begin even before the planting campaign. Planting with disinfected seed material prevents pest damage to the bulbs. And if the pest still appears in the garden, you need to immediately destroy it by spraying the plantings with one of the above insecticides.
