little reddish-brown insects in harvested garlic

Asked July 31, 2020, 1:49 PM EDT

Hi- I harvested my garlic a month ago and it's been drying in my garage. Today I cleaned and prepped it for storage and discovered little reddish-town insects in some of the heads. There would often be a little hole in the wrapper and then I'd find this little guy hanging out in there. I am not sure if it has done damage to the cloves, since I haven't yet used any of the garlic. The insects are small, 3-4 mm. Do you know what this is? Is it something that is living in my soil (I've never seen it in past garlic harvests) or did it come in with the garlic? I purchased and planted new stock this past fall. How can I avoid replanting this problem in the fall? Thanks! Susan

Howard County Maryland

5 Responses

Hi - These are pupae of allium leafminer, a fly that has become a new pest of allium crops (garlic, onions, leeks, chives, and ornamental alliums). You should break open the garlic heads that have visual external symptoms and remove and destroy the pupae. It is possible that pupae might be in heads without external visual symptoms as well. Do not use any of these bulbs for planting your fall crop of garlic.


If you re-plant with newly purchased bulbs, a floating row cover can be used to exclude the adult flies in the spring and fall when they are flying and searching for host plants. Penn State University is conducting research on this new pest and has very good information about it. https://ento.psu.edu/extension/vegetables/pest-alert-allium-leafminer

Christa

Hi Christa-

Thanks for your informative, although distressing, response.
Do I understand you correctly that I should use none of the garlic I harvested this year for planting in the fall?
Or should I just avoid any heads with visible damage and/or pupae?
Also, I bought this garlic from a source in Upstate New York. Do you know if they have this pest there (increasing the likelihood that I planted contaminated stock?)
Thanks for your help-
Susan

Hi Susan,
Yes, that is correct. Our vegetable specialist who studies and tracks this new pest says do not use any bulbs from the field for your fall planting, even if they look OK. The larvae of this fly can go into layers of the garlic bulb as they are developing, and you run the risk of having these carry over to start a new generation next year.

Allium leafminer has been reported in some southern areas of New York state. Penn State has a map of its distribution on its website.
https://ento.psu.edu/extension/vegetables/pest-alert-allium-leafminer

Christa

Christa-
Thanks for the clarification and DARN! That was newly purchased and expensive heirloom garlic; I had hoped to be able to use it for years to come. I guess I'll just have to try to enjoy eating it all this year.
Thanks for your help-
Susan

Susan - You're welcome. And I totally understand the disappointment. I had allium leafminer show up in my personal garden this year too. Savor what you grew this year and good luck in the future.

Christa