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Onion Fly

Delia antiqua

Onion Fly

by cms-admin. All rights reserved

The Onion Fly is ash-grey and looks a lot like a common housefly. The larvae are most problematic in gardens and allotments because they bore the bulbs of onions, garlic and leek. If you find an infestation, it should be removed and disposed of as soon as possible to prevent another generation from hatching the following year. Wilting and yellow foliage is one of the main symptoms.
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Onions, garlic, shallots and leeks may be damaged and made inedible as a result of an onion fly infestation.


The onion fly is ash-grey in colour and looks a lot like a common house fly. The legs are a dark black colour while their wings are transparent. The females are slightly different and lack the longitudinal stripe that the males have down their abdomen. The eggs are white and laid in groups on the shoots, leaves or bulb of the plant. Larvae is also white and cylindrical in shape.


Leaves turn yellow Wilting Rotten bulbs Hollowed out bulbs Plant death











North America, Western Europe, Russia, Central Asia, China, Japan and Korea

Biological treatment

You can buy insect proof netting that will protect any of the flies getting to the plant, preventing them to lay their eggs.

Chemical treatment

You can use insecticides on your soil to provide effective control, this will kill any living larvae


Bulbous plants


Allium spp.

Chinese Chives

Allium tuberosum

Crow Garlic

Allium vineale

Babington's Leek

Allium ampeloprasum var. babingtonii

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