How to Hunt Caterpillars/Worms?

These hungry buggers are here again… tis the season.
I use Bacillus T. and it works, mostly. I want to find and toss the stragglers.

What’s the best way to find them?
? Time of day or night?
? A special light that makes them stand out?
? Most likely part of bud where they can be found?
? What works for you?

I notice the small brownish ones are sometimes hanging from a web-like strand, after falling from a bud…?
? Maybe shake the plant a bit to make them fall, then look for hangers?

Thanks!! We Are the WORM HUNTERS!!! Let’s Get’em!!!

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My fav method is the thwack, plus knit pick at 530am.

This is severe damage and shows an active spot being nibbled.

You can locate what I call tracers which is top level cell damage from small baby caterpillars. This helps identify what tier they are at.

The moth mamma lays eggs randomly soread throughout the plant, caterpillars seem to stay near same tier for a long while.

Some are very very small.

They are different colors at different stages of life. There are 5 in this pic, can you find them?

Small black dots indicate an active caterpillar that has eaten recently and is on that tier of leaf.

They prefer the flowers.
Check for initial leaf damage, then go to flower on that tier. Check up and down.

Check underneath leaves and close to the actual bud.

The hardest thing is their natural camoflauge.

I check for then daily in the early am.
This is when they are just getting up and start moving to feed.

Another method I have started using is the thwacking.
I thwack an entire branch, then jiggle the whole plant like I am shaking almonds. Sometimes they fly off large in numbers and wriggle around on the ground.

Good luck, I have one plant being hit hard now and pick off at least 5 a day for past week.
Mine are also inside my veggie garden, and I have hundreds of bait plants to choose from. Ugh.


Along those lines!:point_up_2:t5: The buggers are SUPER pests in my eyes. Sunrise and sunset is when i fine them most. (Cant look at night) and ive always found them on leaves. And smaller so i caught them very soon. Of course i check my girls against light almost daily. (And they arent very big or very many so its much easier) believe the one larger i found was in my flower. N immediately found before noticeable damage if any.

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Mine all went right into the buds and started eating. The buds would turn black and fall apart where a caterpillar had been. Sounds like a lot of work for poor results: Just buy some spinosad at the home improvement store and spray once a week: Totally bug-free and it works for aphids and thrips as well. Bugs that BT doesn’t affect. Completely non-toxic to humans.

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:thought_balloon: never growing outdoors, never growing outdoors LOL

I don’t think I could take the stress! At least if they have issues inside, it’s probably my fault :wink:


Wow, great info and techniques. The problem I have right now are those tiny camouflage worms that dive into the buds. ***I am so impressed with Evolution! They are so hard to see in there!

Have applied B. t. and will see how it goes. Will try spinosad if it doesn’t work.

What science us there that show BT or Spinosad so not affect humans when burnt and inhaled? Any leads?


Hey All,

I came across this advice in another post and this seemed like the best method in terms of prevention. Will be trying this next year…

I am dealing with a few of these pests myself! It is painful to find them when you are more than half way through the flowering period. I do have Safer Brand 5163 Caterpillar Killer II Concentrate (bought last year when I discovered a bad infestation of budworms) but am reluctant to spray this on all the fat buds this late in the game. What’s everyone’s thoughts on using this product when there is only 3-4 weeks of flower left?

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As long as it is the BT pathogen you are fine up until the day of harvest for certified organic food production. It isnt harmful to us at all.
I would still do a peroxide wash to get everything off :slight_smile:


Thank you!!! :grin:

Will be spraying my babies down this evening with it! Do you recommend fully saturating the plant and bud or more of a light misting over the plant?

Just mist entire plant is fine. It is basically a virus so doesnt take much.

Time to go buy you some mason jars and boveda 62 packs! Get your string ready for hanging and peroxide for washing. You are nearly there!

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Oh yeah! Already got that covered :sunglasses:

Boveda 62 packs and a 12 pack of 32 oz mason jars are ready and waiting! Just gotta stay one step ahead of those devil caterpillars…. They really messed up last years crop on me. I wasn’t as diligent and was trimming through many buds clogged with pillers and there excrement :nauseated_face:

BTW, I was checking out your grow journal and was impressed with your growing in the desert outdoors! Kudos @highdesertfarmer and keep it up, that’s a rough climate for outdoor!


Nice, harvest approaches!!
Re: desert. Thanks friend :slight_smile: It is rough and rewarding!

About a month out myself, chomping at the bit over here.