Tomatillo potato beetles...

[pondgardener]

Growing tomatillos for the first time here (7 plants) and this morning discovered a bunch of what seems to be three lined potato beetles. Crushed a couple that were trying to enlarge their present families and disposed of about a dozen others. I ordered some insecticidal soap with pyrethrins and will probably start with that initially besides disposing of those I can catch. Anyone else have any suggestions about what and when to spray or use to deter these pests?

[pepperhead212]

I never noticed those on my tomatillos, but I spray Surround on my tomatillos on a regular basis, to keep bugs off of them. Seems to work, as they don't get peppered with holes, like they used to. Not sure what did that, but they still produced tomatillos, with no problems.

[pondgardener]

@pepperhead212 So far there has been no leaf damage as they may have just arrived in the neighborhood. The plants are producing loads of tomatillos and I want to avoid any problems. The arrival of striped cucumber beetles is not far off, so what I use for this pest may work on those. When using Surround, does it affect the bee population or do you spray during periods of no activity? One thing I read about mixing pyrethrin is that the water should not be a high ph value. Our water is relatively high in ph, so I am thinking about using distilled water, which after being exposed to carbon dioxide for a few hours, becomes mildly acidic.

[pepperhead212]

@pondgardener Surround doesn't seem to bother the bees (while spraying I do watch for them, and try not to get any on them in the flowers!), and it does keep those beetles off cucumbers, and similar plants. And it keeps flea beetles off eggplants - a major problem I used to have here. The only things I don't spray it on are cherry tomatoes and hot peppers - too much of a pain to get off those small fruits, but it wipes off the larger tomatoes and other fruits easily enough. It stays on fairly well with light rain, but most will come off with a heavy rain. But I try to spray it on the undersides of the leaves as well as I can, which stays on very well.

[Toomanymatoes]

They have ravaged my groundcherries this season (tomatillo's and groundcherries are both Physalis sp.).

Not sure if it happened this year because I grew a different species compared to last year (Physalis peruviana and P. pubescens vs pruinosa ). Found the lined potato beetles, their larvae and plenty of eggs on my two plants at home and the three in my community garden. I keep squishing them whenever I go inspect my plants. The plants in my community garden are coming back, but the ones at home are recovering.

These larvae are gross. They store their poop/frass on their backs and are just plain nasty looking.

I also keep seeing this solid red beetle as well. Been meaning to look it up to see if it is friend/foe.

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[GoDawgs]

There was a spray containing a certain variety of bt (kurstaki? maybe israeliensis?) for control of CPBs, Now I see there's another one out there containing a new version of spinosad and made by Bonide.

I handpick mine off the potatoes and do a thorough inspection of the leaves for eggs or freshly hatched young'uns. It's a pain to do but is effective. I think dealing with the first batch (there may be a second batch of CPBs later) lasts about two weeks, at least it does on my potatoes. CPBs are most active in the morning so I do my patrolling before 10am.

You might want to make a note of the date you first found them so that next year you can start watching for them about a week or so before that date. Getting the early birds is key to keeping the total number of CPB's down. For sure you want to plant your tomatillos in a different spot next year to avoid reinfestation when the beetles emerge from that soil next year.

[pondgardener]

@Toomanytomatoes So far all I have seen are the breeding pairs on the plants and very little damage done to the leaves. I did read about the larvae expelling their poop on their backs to discourage predators. Gross looking! I squashed another dozen beetles today and will go looking again tomorrow.

[GoDawgs]

Interesting. I've seen CPB larvae here in all stages but none with poop on their back. I'm wondering if we're talking about two kinds of potato beetles.

Edited to say that I "have" seen CPB larvae in all stages, not "never seen". Good grief, I WISH I had never seen any!

[pondgardener]

@GoDawgs Yes, you may be thinking about the Colorado potato beetle and what is referred to above is the three lined potato beetle. Looks very similar to the cucumber beetle, but these seem to have a preference for tomatillos, although they can move onto other vegetable plants in the same family.

[Toomanymatoes]

@Toomanytomatoes So far all I have seen are the breeding pairs on the plants and very little damage done to the leaves. I did read about the larvae expelling their poop on their backs to discourage predators. Gross looking! I squashed another dozen beetles today and will go looking again tomorrow.

I only have 5 plants, so I just been checking the leaves and squishing them as well. They seem to have been laying eggs since early June here. I found several more egg clusters and some beetles gettin' busy on my plants a couple days ago as well. I am hoping they are done soon.

[pondgardener]

@Toomanymatoes I have 7 plants spread around the garden, with 4 bunched up together. I squished another dozen or so today and found a couple of clusters of tiny orange eggs on the top side of the leaves. I hope they don't start laying eggs on the underside as there are too many leaves to have to turn over. The egg clusters do stand out pretty well against the green foliage.

[Setec Astronomy]

Funny, I just killed a three-lined beetle this morning, I thought they were done for the season. I seem to be getting fewer every year, I try to get after them killing the adults, squashing the eggs, and wiping off the larvae with a paper towel. This is on my ground cherries. I don't remember having them when I first started growing ground cherries, then all of a sudden I had them, and wondered to myself where they came from (because who nearby is growing potatoes or ground cherries?). I have a friend who doesn't know anything about gardening and who's generally an idiot, but he has his savant moments, and he suggested maybe they came with the plants (this was back when I was buying seedlings instead of growing them myself). So maybe that's it and I'm gradually defeating them.

[JRinPA]

Eek....the one year I grew tomatillos successfully, we had so many I never felt like growing them again. But...I don't recall any pests on them at all. We have mostly false colorado around here, once in a while a colorado. They make the same booger bug larvae. Thankfully I've never seen those pooper troopers!

[Setec Astronomy]

I just killed 4 more Three-Lined Potato Beetles this morning, including one on top of my sprouting broccoli, which was a little weird (although only a few feet away from a ground cherry). My state ag extension says potato, tomato, and sometimes eggplant, but I only seem to get them on the ground cherries, even though those are in a sea of tomato plants.

EDIT: I was just reading my ag extension page again and they say there are two generations per year, so that explains why I've got them again. I think it also explains that weird wormy thing I found crawling on my arm outside a few weeks ago, I think it was a new larva without the poop blob so I didn't recognize it.

[Shule]

We've had a few three-striped beetles on our tomatillos in the past. I think I shared a picture of them either here or on Tomatoville within the last two or three years (but the picture wasn't the best). I just left them alone, and they didn't seem to do any real damage (but the plants didn't produce much, either--they probably needed fertilizer, as those containers had had peppers growing in them for years).

[Shule]

Here are some pictures of them (it was in June of 2020):

[JRinPA]

I have never seen that three stripe that I can recall. Mostly just the "false" (until just now I thought it was called "false colorado"), and usually on eggplant and fairly controllable with some patrolling booger bugs. The false potato beetles are actually pretty nice looking bugs.

[Shule]

@JRinPA

Mine look different than all the pictures I find online. They're more of a cream/white color, while the ones online are orange-ish or a deeper yellow (I'm not just saying that from the picture, but from memory, too). I don't recall mine having red heads, but I guess it's possible.

[Setec Astronomy]

Mine look different than all the pictures I find online. They're more of a cream/white color. I ddon't recall mine having red heads

Maybe you have striped cucumber beetles:




That's from this page: https://entnemdept.ufl.edu/creatures/VE ... eetle.html

When I was looking up the Three-lined Potato beetles yesterday the Striped Cucumber beetles were noted as a similar-looking insect.