webby caterpillars on my baptisia

I discovered these worms all over my false indigo yesterday. They're yellowish green, with black and white spots. They make webs, but not particularly dense ones, like tent caterpillars. Most of the ones I saw were one to two inches long. I snipped all the ones I could find with my scissors (I was cutting out the dead/eaten branches anyway) but I knew I had missed many. Tonight, I found many more, plus several swarms of tiny ones.

What are they, and more importantly, what do I do about them? I could probably cut the affected branches out, put them in something and then burn them, but I doubt I'd get them all, since some of them could fall off and escape.

Okay, thanks to someone else's post, I've determined they're Genista Broom Moth caterpillars (Uresiphita reversalis). Any suggestions as to what to do to them?

spray with Bt or Spinosad, both organic and a total fix. they ingest the leaves and die.

Thanks, trackinsand. I'll give one a try.

Bt is sold under the brand name Thuricide. Spinosad is sold under several different names.

Found these catepillers today on my baptisia. The top looked almost burned as there was so much eaten and so much frass. Thanks for the information. I have spinospad in my stash (no bT) so I sprayed it tonight; fingers are now crossed that those pesky catepillars are done in.

I've used Neem with some success on my lupines. It has to be reapplied every week or after it rains. I didn't look at my baptisia. I better check!

Thanks for mentioning baptisia as a food source for these caterpillars. I just checked, and there they were, munching away. This time I sprayed with Bt, and I hope they're gone by tomorrow.

Bt must be re-applied periodically but one spraying takes care of the present population. be careful with neem in sunlight. it will burn as it is an oil that lays on the leaf.

That's why I always spray in the evening. I learned the hard way when the sun came out shortly after it rained. I have a question, though, that seems to have conflicting answers. I read where Neem needs to be mixed fresh every time, and that once it is mixed with water, it cannot be used effectively the next day. True or false? The directions on the Neem concentrate I bought do not mention this. It seems like a major waste to mix up a fresh batch each time it is used.

i'm no expert on anything but when i mix up a batch of anything, i try to use it within 2 days. otherwise it clogs my sprayer up. i don't know about something like Bt maybe losing its strength but i wouldn't think that would be much of a problem with neem.

neem eventually solidifies in water and won't mix properly. if i were you, i would just make very small batches. i use a one gallon pump up sprayer or a hand held spray bottle for all of my spraying. it takes me 4 gallons to spray everything in my garden and surrounding areas whether it's spinosad or foliar feed. for specific plants, i use the spray bottle.

Thanks! I usually mix small batches of Neem or Bt (one quart at a time) in a spray bottle, but it might take me a week or longer to empty the bottles. My garden isn't that large, and I try not to spray unless I see real destruction. I keep shaking the bottle between plants so the active ingredient doesn't settle. I wonder if I'm spraying "nothingness" by the end of the week?

i don't think so. i think your mixture is fine in one week. i think sometimes "they" say that so that people don't have unlabeled product sitting around that could be toxic, like round-up.

Thanks for the info. I'm glad to know that I haven't been spraying in vain.

Just for the record, those Genista Broom Moth caterpillars are very persistent. Every time I check for new growth on my lupines and baptisia, I see a new crop of webs, eggs, and caterpillars. They seem to like lupine blooms as well as leaves. I've alternated mainly between Spinosad and Neem, but I've also sprayed with imidacloprid (Bayer Rose & Insect spray) because of the constant battle.