Help with onion flies?
This past year was our first year for growing regular onions. We've grown garlic, leeks, Egyptian onions, and chives for years with no problems, but this past year the regular onions all were infected with flies. I'm not sure if these were onion maggot flies or not. The adults were about 1 mm long with black wings and the maggots were white and about 4 mm long. On each onion plant, where the onion bulb met the surface of the ground was a hole where the flies were entering and exiting. I tried spraying with both sevin and permethrin, but neither helped. Is there anything that I can do so this doesn't happen again next year? Thanks.