Tuesday 16 June 2015

Leek Moths on the Garlic


I've been taking a closer look at the garlic plants lately (mostly just checking for scapes to harvest) and just last night realized I have leek moths.  These are an invasive species of moth from Europe that was accidentally introduced into the Ottawa area (where I'm located) in 1993.  It has since spread through Eastern Ontario, into Quebec and as of 2013 was found in Southwestern Ontario, Prince Edward Island and New York State.  Ugh.



They like all alliums, with their favourite being the leek.  I don't have any leeks.  So they like my garlic for now (and may switch to onions next, who knows).  They bore into the flat leaves (or the inside of onion leaves which are hollow) and eat them inside out.  They continue to the centre of the plant. 














For my garlic, it means the infected plants were damaged at the stalk and won't be producing any scapes (in my case, I found some larvae still inside the small scape that was growing).


Row covers will help ... in most areas they just need to be put back on by dusk and can be removed during the day.  In my area, row covers would need to remain permanently on until harvest.  I have friends who grow garlic that don't bother to cover and just take a chance that they'll have some survive.  I've definitely thought I had leek moth damage in previous years (mostly last year), but had never seen the actual larvae until now.


Why are bugs so creepy?!  After spending an hour removing any I could find, I had to come in and take a bath as I kept feeling like something was crawling on me.  How did I go from being a suburban kid afraid of any bug that came near me to being an organic gardener?  I should review my life choices sometime ...

In the meantime, I'll have to keep an eye out.  No point putting row covers on now as there could already be eggs in the soil waiting to hatch.  I found various stages - the pupae in the main photo, the larvae (you know, wiggly creepy wormy things) as well as the empty cocoon stuck to the leaves.  Out of about 70 plants in total, 20 or so probably were infected.  I'll keep them in the ground as I could still get useable garlic if I managed to catch them before they burrowed into the stalk.  So I'll just keep watching them and will pull them early if it looks like they are continuing to spread to other plants (I might be making Michelle's Crema di Green Garlic soon!).

There are various articles on Government of Canada or Ontario Agriculture Ministry sites.  Here's a link to the one I found the background info I mentioned in the first paragraph.

http://www.agr.gc.ca/eng/about-us/offices-and-locations/pest-management-centre/publications-and-newsletter/sustainable-crop-protection-factsheet-series/an-integrated-approach-to-management-of-leek-moth/?id=1243356171595


9 comments:

  1. Oh dear. If it is in New York already it won't be long until it gets here. I already cover my onions. When it happens I'll cover the garlic too. It would be so much easier if we didn't keep importing new pests. Good luck. I hope you still get a good amount of garlic.

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    1. Yes, that's why it's so important to keep things (produce, firewood) local and avoid transferring pests to other areas. That's why we have so few ash trees left in Ontario as well.

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  2. Oh boy, and only last year I thought alliums were one of the few carefree plants - until I discovered the onion maggot. Even though my garlic did not get infected, it is covered as the shallots are in the same bed and they did have onion maggot damage last year. I guess that's a good thing as I am most likely avoiding this new threat. Fingers crossed that you still have a good harvest this year & not too many more of your garlic becomes infected.

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    1. "They are coming your way" ... wwwoo0000oo000ooohhhhh (supposed to be an ominous ghostly sound).

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    2. Umm, just joking you know? :)

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    3. Hee hee hee - I'll be fortifying my defenses - gotta plug up those gaps in my netting!

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  3. Well that is a new one to me. Please, just keep this to yourselves in Ontario. No exports needed.

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  4. I know its an old topic but I am in southern ontario, north of toronto and since 2014 have had my leeks completely ravaged by this pest. prior to that i didnt see a trace of one. I have found pheromone traps online but they only seem to be available in the UK and impossible to have shipped here. i tried a combination BT and Pyrethrum spray, and last year and it worked OK but i still lost 1/4 of my plantings. THis year I tried covering and growing in pots and somehow already have damage!

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    1. I've only had them this one time (keeping my fingers crossed for this season) and my only means of managing them was to handpick them off the plants. Awful things.

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