New pest need help identifying

We found this grub/worm recently in a customer’s field in Wisconsin. Have not experienced this pest yet and could use help identifying.

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Bud worm

Borrer worm

Sprinkle DE all over the base of the plant


We always called them “corn borers” when I was a kid. They can take a 15-foot cannabis Christmas tree down outdoors. Little bastards

It can’t hurt, but would DE just at the base fix it if they are attacking the stems? I honestly don’t know.


Spinosad will also work. Some say neem oil, but imo neem is just a “shampoo” for bugs.


I thought maybe corn borer but couldn’t find similar photos online. Not major pressure in the field but a first for me. Thanks!

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I swear I read a thread about a border bug a few weeks back. It had to have been over at or thcscammer.

Pics n all.


Thanks a lot for the input!

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Always glad to help, and occasionally stir the pot.


I’ve never quite nailed the identification, but have seen plenty of these evil little worms here in WI. They love to eat seeds, and burrow into the stems. They leave a trail of mold causing feces and damage wherever they go.

I’ve had great results controlling them with alternating sprays of bt and spinosad. I also try to remove any affected areas of the plant, but sometimes they have burrowed into a main stem that I don’t want to cut out. Then it’s time to dig the little bastard out with some pointy tweezers.

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What part of WI are you in? Seems they are in the CBG more than CBD, CBG all finished early and are being harvested now. Did you get hit with that crazy wind storm a few weeks back?

SW WI. Yeah, we were hit really hard with the wind down here. Luckily, everyone in my family got by with almost zero property damage. My grandparents’ house had a small dent in their rain gutter, and one broken window. Lots of trees down everywhere though; they’re still cleaning up piles of brush from the storm.

I’ve only seen the bud worms in thc plants and ditchweed out in the wild. Haven’t grown any cbd or cbg strains yet. They are much more of an issue with plots that only get checked on a few times over the season. Pretty easy to knock out with a couple sprays.

I just pulled a couple early Nep Jams about a week ago. I had sprayed them once with spinosad almost two months ago, and only found a few bud worms.

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There is also a hemp borer:


Glad to hear you made it out in good shape, freaky storm…that’s pretty good results with one app of spinosad. Thanks for sharing.

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Bingo! Thanks so much, great reference.

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We had hemp borers in NE WI last year. Make sure you till or cultivate in your stems. They can over winter in the stubs.

Spinosad can remain in water for over 6 months
I’ve personally seen a couple light applications during early flower make material test hot for months. Also, introducing the chemical to your local watershed will kill fish and other aquatic things :frowning:

Eurasian Hemp Borer. If you’re using bamboo stakes they’ll chew their way through the core of those to get to your plants… having to bifurcate half our stalks was not fun.