Soak onion in a weak solution of potassium permanganate in a half - hour before boarding.

Do not plant onions every year at the same place.

Plant onions nearby or in the same bed with the carrots. These vegetables – the allies and help to get rid of each other from various kinds of pests.
Cultivate the land, which grows onions, wood ashes. This deters onion fly, besides, ash is an excellent fertilizer.
Prepare the saline solution. Make the first treatment, when the onions will sprout out of the ground 5 cm Dissolve 300 grams of salt in 10 liters of water, sprinkle the onions with this mixture.

Produce a second treatment in 2-3 weeks, take 450 grams of salt in a bucket of water.

The third processing take three weeks after the second, bring the amount of salt up to 600 grams per bucket of water.
Sprinkle the bed, which was attacked by the onion fly, with a mixture of baking soda and coarse salt, in the proportion 1:2.
Plant onions next to the bed where you grow tomatoes, because the onion fly can not tolerate their smell.

Make next planting of onion flower beds with growing marigolds. It will scare away the pest.
Multiroute a bed of onions to dry manure (only when landed).
Pour a bed of onions with a soap solution, making use Laundry soap, at the rate of 50 grams of soap in 10 liters of water.
Mix the powder of tobacco, grinded hot pepper and ash. Sprinkle this mixture affected fly the onion bed.

Pollinate onions tobacco dust in its pure form, you can mix it in half with ash or lime.
Multiroute landing or planting onions peat. Onion fly are much less likely to attack such seeds.
Pour struck the bed of such a solution: in a bucket of water take one Cup salt and two tablespoons of kerosene, pour on a little under each bulb.
Mix the sand and naphthalene in a ratio of 10:1. Sprinkle this mixture in the bed, which was attacked by the onion fly.