I am not sure what kind of caterpillar that is, but usually, unless it's completely infested, I just pick them off by hand. I drop them into a cup or pail with some soap and water in it, and they die.
In the case of tented branches, usually with tent caterpillars, I bag the branch and cut it off. I like to use heavy kraft paper leaf bags because they burn nicely when I then throw the package on the burn pile.
The in-between method usually involves spraying the affected branches and leaves with soapy water.
It's certainly possible to get them without killing the plant, but other methods usually harm the plant more.
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
I plant things and provide habitats that wasps like. As much as yellow jackets are disliked, they are effective hunters and I'll see them a lot searching for caterpillars. But to achieve that you need to be proactive about it rather than reactive to the situation when it happens.
If you can't get another organism to do the job (wasps, birds etc) then you will have to do it yourself unfortunately.
Chris Kott wrote:I am not sure what kind of caterpillar that is, but usually, unless it's completely infested, I just pick them off by hand. I drop them into a cup or pail with some soap and water in it, and they die.
Yeah, I pick them off too--and step on them. My son will help me but refuses to touch them without a gardening glove on.
My chickens won't eat caterpillars, though I'm hoping our new ducks will (cabbage worm season is starting soon here). My philosophy is live and let live with most things in my garden, but I squish cabbage worms and slugs/snails on sight.
I agree with Chris although I'll tell a related story: The first spring after I arrived in BC corresponded to the 7 year high in tent caterpillar cycle and the appletrees near the house were being consumed. My husband insisted on trying the "burn them approach" but I was afraid there wouldn't be much of a tree left. Instead, every morning I went out wearing rubber gloves, pulled the tents off and stomped on them on the driveway. I also learned that if I saw a tent caterpillar with a white dot on it, it had been infected by a parasitic wasp that would get the whole problem under control if the "white dotted tent caterpillar" was allowed to live. That experience got me moving towards permaculture - working with nature, so she'll help us out.
So Chris's approach will save this year's crop, but reading lots of the forums here at Permies will help you follow that up with Nick's approach and the many other things we do here to promote a healthy, inclusive, diversified garden/polyculture/food forest that will help prevent a single troublemaker from invading in the future. I leave any wasp nests that aren't in a problem location and that aren't being aggressive towards me, but I also leave plants to go to seed so the birds will hang out and eat bugs, and the ornamental pond installed by the last owner is largely left alone during tadpole season. I've been here 20 years now and I see birds, snakes, frogs and friendly wasps all the time. Last year I had to apologize to a tree frog who was hiding in the lettuce plant I was picking leaves from. I thought the squishy feeling was a banana slug I was going to have to re-locate, only to discover a ticked-off frog! I carefully replaced it among some leaves I wasn't planning to pick.
If you want to do double duty, find someone with chickens and see if they like them. (Chickens *don't* like the taste of tent caterpillars.) I had a friend who was having a bad slug problem and she used to save her slugs in a bucket for my ducks. Once she got her garden diversity up, the slugs no longer took over.