latest brassica pest: cross-striped cabbage worm

Cross striped cabbage wormsSOMEONE’S SUDDENLY EATING HOLES in my Brussels sprouts plants, and it isn’t the usual earlier-in-the-season suspects—those fuzzy green cabbage worms I’ve written about. My new visitors are apparently cross-striped cabbage worms, which can pose a serious problem to home gardeners because they’re prolific egg-layers producing multiple generations a season. Oh, dear.

(They’re also really beautiful, if you look at them up close–but beautiful in the way that Japanese beetles are beautiful, meaning not enough for me to count them as beloved pets and keep them around or anything.) Squish!

The cross-striped cabbage worm larvae are sort of blue-gray, and as their name suggests striped across their bodies. Not so many years back, it was more a pest in Southern farms and gardens, but has gradually made its way to southern New England, at least. I read up on them in various places–U-Mass Amherst; at the University of Georgia, and so on–and what I concluded (as I said): Squish! 

I’ll be vigilant about fall cleanup and follow all the steps I’m already practicing to stay ahead of other cabbage worms, like this. I don’t use pesticides–not even ones rated for organic gardening and specific to caterpillars, such as Bt–and I manage to harvest plenty of food most years, anyhow.

See photos of its other life stages of the cross-striped cabbage worm in the Moth Photographers Group website, or at BugGuide.  Ever seen any in your brassica bed?

  1. Hannah says:

    Ohhhhh, the cross-striped cabbage worm. They decimated my kale. (I live in Kentucky). For much of the season, I was able to keep up with squishing and scraping off the eggs from the backs of the leaves. But my travel schedule meant too much time out of the garden, so I finally gave up and ripped the kale out. I’ve started some kale and swiss chard seeds, and am hoping to transplant them this fall into the other side of the yard. I’m not terribly optimistic about the potential for a new fall crop, but since I had the seeds, I figured why not?

  2. Nikki says:

    I battle them every summer! A family event kept me away from the garden for a few days and there lots of the little ‘beauties’ on my broccoli last week. Too many, too small to hand pick. Sprayed with spinosad, a day later trimmed off all the shoots. Plants are looking good again, new shoots forming soon!

  3. Bee Balm Gal says:

    Regarding another bug issue, have you seen any monarch butterflies yet? I have not, in my own butterfly-friendly garden, and it worries me. I am asking other gardeners and outdoor nature enthusiasts and have not received encouraging reports.

  4. Jennifer says:

    I found these worms nestled in my Brussels sprouts earlier this week in my zone 5B Indiana garden! SQUISH is right! I don’t see any more cabbage worms right now, but I had plenty earlier in the season.

    Bee Balm Gal, I, too, wondered why I have not seen any monarch caterpillars on my Ascelpias tuberosa. Last year I had lots of larvae and 2 chrysalises. Anyone have any answers?

    1. margaret says:

      Well, Jennifer, though I am sorry you have them, too, at least I am not alone. They are beautiful, aren’t they?

      Sounds like you are a veteran, Nikki. Wonder why I never had them before…

  5. Choral Eddie says:

    After picking off the cabbage worms feeding on my Kale and Broccoli all summer, I’ve given up and let them have their way. Those that I picked off I threw on top of the compost pile and the neighboring birds scarfed them down. Never had this many worms before.

  6. linda says:

    Here’s what I read about the Monarchs…
    Conservation biologist Kent McFarland with the Vermont Center for Ecosystems tells Vermont Public Radio difficult weather systems in the last two years have contributed to problems for the monarchs. Agricultural practices also have reduced their breeding habitat.
    Their numbers have steadily declined-in studies since 1996, the amount of acreage they use (in Mexico) for breeding, which is how they estimate their numbers, has declined from 15 to 3.

  7. Lynda says:

    I found these for the first time this year, but they weren’t on my brassicas, the were on my horseraddish! I usually feed all the worms and bugs I find to my chickens and they scarf them up. Strangely, they did not want anything to do with these little creapy crawlies. Perhaps chickens don’t like blue food?

  8. Vicki Ligen says:

    I have had trouble with them in my garden this year on my kale. I make a strong solution of Dawn dish soap in a squirt bottle and spray them with it. Kills them and does not bother my kale. Because they are so prolific in reproducing you have to spray every couple of days. I even pulled out some older kale and a short time later I found a bunch of them coming our of the dirt right where the old kale had been. UGH! Spray, spray, spray………

  9. Vicki Ligen says:

    Regarding the Monarch butterflies I think their numbers are down everywhere. Once they use to cover acres in Mexico during their winter migration and I think I read where last year they were down to about an acre. Please people help save the Monarch and plant milkweed. Unfortunately I think the decline of the Monarch and our honey bees are the result of the same thing. All the chemicals they spray on food crops. GMO’s seem to be the worse offenders and they have only increased the use of chemicals sprayed on our food and not decreased it as the companies that make that stuff falsely claim.

  10. Debra Petke says:

    Our brussel sprout plants have also been eaten to a lacy mass of leaves, although the stems remain strong and new leaves are emerging. We also have never had this problem before. We used Captain Jack’s Dead Bug Juice, a terrific organic treatment that solves many problems and did take care of these worms. The plants do look like a prop from The Addams Family tv show. Although I agree with you, Margaret–they are beautiful creatures.

  11. Corona says:

    This has been pest on any kind of cabbage varieties * including chinese mustards and radish leaves from day 1 in north carolina zone 7. I picked and picked and picked, they come back in hundreds…I eventually gave up and pulled the plant which is only left with stem and no more leaves. I’ll not be able to grow any greens in summer. Recently, I saw a trick from organic magazine and I intend to try to see it works. Slip a panty hose over the cabbage. As cabbage grow, the hose will expand. Dollar Store will be my next stop!!

  12. I garden organically in rural Missouri and unfortunately am all too familiar with them, though I never knew the exact name. Multiple generations a season is right. This is by far the worst year we’ve ever had, but I think the glorious (to everybody but the tomatoes, rosemary and lavender) 14 (!) inches of rain we received last month, along with cooler than usual temps played a big part.

    They LOVE kale – especially Russian Red, aka Ragged Jack. A new generation is decimating my beds as I type (I sometimes spray things like DE and garlic juice in the garden, but am really lazy about it). My favorite year round green to grow is Swiss chard, partly because the cabbage worms thankfully ignore it.

    There are two upsides (if you can call them that :) to these infuriating, ravenous creatures – the kale will grow back if you cut off all the ugly, hole-filled leaves (I’m on my 3rd or 4th cutting from seeds I sowed last year) and the chickens LOVE being served meat with their veg. ;)

    Thanks for all the helpful info you share with us, Margaret – and good luck! :)

  13. Eve Mauger says:

    I must have removed the row covers too early, because the cauliflower were totally destroyed by these worms. I found them all in the soil after we pulled up all the plants. We had not seen them on the plants somehow; I had been searching for cabbage worms, but didn’t see these cross striped cabbage worms. Thanks, Margaret!

  14. kim says:

    This is my first time growing Brussels sprouts and have noticed holes in my leaves. Thanks for letting me know what is causing it.
    I am thinking of getting ducks or a few chickens to help out.

  15. Lois says:

    I live in Northern Virginia & I had never heard of or ever seen these things before they appeared in your column. Then yesterday, when I was out with the hose watering one of my raised beds (with a huge, gorgeous, loaded pole bean tower), I noticed a big marigold plant ( a marigold for pete’s sake!!) on the border was almost totally skeletonized. Looking closer, it was covered in the same striped worms you wrote about! When I got back inside I looked at your blog & the photos to verify they were in fact “cross striped cabbage worms”, who all shortly got picked off & drowned in a tub of soapy water.

  16. Sheryl says:

    I have them too now! They seem to like the undersides of the leaves the best.They nearly decimated one of my russian red kale plants and were also working on the brussels sprouts more so at the top of the plant. Lacinato , starbor, winterbor kales have some too but their favorites are the sprouts and russian red kale. Nothing really has bothered my kales before except the lacinato with the green cabbage caterpillars. These black caterpillars are far more prolific than the green ones!! Squishing has been my attack and also am cutting some of eaten leaves out.

  17. Heather says:

    On a recent ABC Gardening tv show it was shown that growing Cress ..American Upland (barbarea vulgaris) may help in stoppng the white cabbage butterfly grubs from decemating your cabbage plants ects.
    Apparently they eat the cress and it upsets their stomach , I only planted 1 Kale and I am still picking whole leaves.

  18. Darryl Vergonet says:

    I’m so happy to find this web page about the Cross striped cabbage worms. They have totally decimated my cauliflower and broccoli and now are working on my brussel sprouts. They are too plentiful to pick off there are dozens of them hiding in each plant from the tiniest leaves to the largest and all through the heads of my cauliflower (which I finally gave up and fed to the chickens. I live in southern Michigan right on the Indiana line and have never seen these before this year. There is no comparison between them and the usual little green cabbage worms. They are voracious eaters and I can’t seem to get rid of them.

    1. margaret says:

      Hi, Darryl. I only have them on occasional years. I was VERY stern with them the year I took these photos…and checked the plants for eggs and worms every day and squished all I could find.

  19. Reeve says:

    I live in Western Mass and finally got around to growing some kale this year for the first time. Wow! These pests are astounding! I refer to them as zombie caterpillars because no matter how many I squish, it seems like there are just as many the next day. I’ve never seen anything like it. I just bought some diatomaceous earth to try to fend the slugs off of my basil plants; I think will give it a try on these critters as well.

  20. Lynne says:

    I thought I had gotten rid of the early cabbage worms by harvesting the collards and kale early but I left the plants to regrow. What appeared on the beautiful new growth was this cross-striped fellow – and dozens of relatives. What a mess. Collards and kale a total loss – I just couldn’t keep up with them. Next year I will try row covers.

  21. Robert Kesner says:

    Oddly enough, I had fewer pests this gardening season than ever before. Typically, I would have my fair share of cucumber beetles and Japanese beetles but nada this year. I now only garden with 10 raised beds (10′ x 4′ each) vs. my 12,500 square-foot “garden” that I had 4 years ago, all organic btw, and rotate the crops each year, add compost, etc. The two issues that stand out as differences between this year and past years: in our part of VT (just north of Middlebury, VT) we had almost no precipitation (my pond has been down 2 feet since June), a lot more heat and humidity; the other is that I amended my soil using some different compost/topsoil (organic, again). I use straw as mulch and occasionally some floating row cover but have done so in the past, too. I am a Master Gardener, btw (I do not pretend to know all of the answers, though!) and so follow area gardening issues, but still not sure why I did better than usual vis-a-vis pests.

  22. Mary Ann Mascia says:

    This is the first year that I had worms on my lettuce plants, after reading the above I can see that the kale that was mixed in with the rest of the lettuce seeds, was the main target. I started the plants from a seed packet of mixed lettuces. I had the worms on my mixture of lettuce and they ate some of the lettuce leaves, and they enjoyed the kale the most. The first batch of lettuce I planted earlier in the summer did great with no worms at all. But it seemed latter into the summer some of the older plants got these worms on them. I planted a second crop of the lettuce and the little varmints ate the kale that was mixed in with the lettuce. I took some of the worms off, but I’m not certain about eating the lettuce now. Any comment on that?

    1. margaret says:

      It’s often the case that an earlier or later planting may have more or less pest damage since the pests have their own life cycle, too — because whichever vegetables coincide with one generation or another of insects get hit harder. There is no danger in eating vegetables with holes or nibbles from insects — it’s just cosmetic.

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