I’m in northern Ontario and these little buggers have been after my garlic and onions for a few years. I go out to the garden 2-3 times a day and remove any leaves that look damaged and hunt, find and squash any of the maggots I find. I didn’t have an amazing harvest but it wasn’t horrible. I have clear tarp over the areas I will plant my garlic- this year and onions next year. Im hoping covering them with while they grow will stop them.
What should you do if you have already found evidence of ALM activity? I found the puncture marks. Is there an organic treatment for garlic besides just getting rid of it?
Organic insecticides: Neem oil or spinosad. The latter is absorbed into leaf tissue so will control larvae after they hatch and start to feed. Apply spinosad after white dots (oviposition marks) appear. Make a second application two weeks later. Since Allium leaves are waxy it is recommended to add a surfactant (e.g. insecticidal soap) to help insecticides stick to leaves.