Bug Battles: What’s Eating My Tomatillos?

By

July 11, 2014

The first year I grew tomatillos I had one plant. The weather was awful. I finally got a couple handfuls of ripe ones right before the early frost, but not enough for canning salsa… so the next year I planted six of them. Holy cow, I got wheelbarrow loads of tomatillo fruits. Not because the weather was better, but because cross-pollination makes them exceptionally prolific. Unfortunately, some itty bitty larvae had made pinhole tunnels in 99% of the harvest. Yeah – it was a total loss. I gave up hunting through a bazillion damaged fruits trying to locate more than a couple I could use.

Over the winter, I tried to discover what bug’s infants laid waste to my mother-load of tomatillos. That was 4 years ago, and I still have no clue. It seems that my garden is very special. No one else in the world reports this kind of damage to tomatillo fruits. The closest I can come to it is tomato pinworms, but they’re bigger than whatever does this to my crop. “Maybe it was just a one-year fluke,” my dear friend the Dept. of Ag Plant Pest & Disease Inspector says. “Some unusual pest that came with the wet, cold weather. Get me a specimen, and I’ll take it to the lab.” We couldn’t identify them because all I ever found was tunnels, and without a specimen of the perps, even the world’s greatest bug specialists can’t help me. Which doesn’t help me pinpoint the way to get rid of them.

What's eating my tomatillo plant?

So, I planted them again in the spring. Now something is eating the leaves. Who cares! I was worried about fruit, and there was scads of them developing amid the hundreds of yellow flowers. Those larvae are way too fat to make those tunnels. They did however enter the pouches through the tip and tear big holes in the tomatillos. And whatever miniscule varmint is making this tiny tunnels is in there doing the deed right along with those striped things. Definitely time to kill everything that moves on a tomatillo plant, but the bees who make this elusive harvest possible. The problem was I didn’t want to use chemicals. Soapy water wasn’t doing the trick, and there were hundreds of those bugs who are very adept at hiding in a blink.

[column size=one_half position=first ]Three-Lined Potato Beetle Larvae (Courtesy of Scott  State Park)[/column]

[column size=one_half position=last ]Sex On A Tomatillo? Three Lined Potato Beetles[/column]

Tomatillo Loving Potato Beetle EggsBattle Year 3 planting season rolled around. Those leaf eating bugs moved right in. Those were easily identified as three-striped potato beetles (more orange than a three-striped cucumber beetle). So, I armed myself with organic AzaSol, which will control all kinds of plant pests. And every time I sprayed rain fell soon after, sometimes before the stuff can dry. Fine. I’ll just start smashing them. Bugs. Eggs. Everything I find but bees. Who cares if the larvae are slimy, and carrying their poop around on their backs. Ignore the gross factor – squish ’em anyway. They. Need. To. Die.

Between my murderous frenzy and AzaSol (you can’t find them all once the plants are thick and huge), I finally succeeded in getting enough undamaged tomatillos to make that roasted salsa and green sauce. It only took 4 years. And 4 heavily loaded plants.

But, I am victorious. Really glad that beetles only bite leaves 🙂

Do you know what makes these pinhole tunnels?

The entry and exit is between a pinprick and a pinhead wide, many so unnoticeable the tomatillo looks fine until you cut it in half. Lots of them have no holes in the husk either.

The creatures just tunnel straight through. Nothing is left behind. It’s a clean, precisely bored passage. They never wander around. It doesn’t appear that it is hungry like tomato fruit worms, because wouldn’t the thing stay in there munching away at the rest of the meat? Of course not! It just moves onto a fresh one, and repeats the process – or grows wings and flies away.

You would think you could clean it up and use part of the fruit for instant cooking, but like an apple, it turns the inside of the tomatillo brown from exposure to air. There are no other visible exterior signs of rot or damage. The only bugs on the plants are these potato beetles. If I cut open a tomatillo and find a tunnel this fall, I’ll add a pic of the hidden damage to this post.

Anyone who knows the answer to this maddening riddle – PLEASE SHARE!

Amber

Amber

Contributing Writer at Garden Culture Magazine
The garden played a starring role from spring through fall in the house Amber was raised in. She has decades of experience growing plants from seeds and cuttings in the plot and pots.
Amber

19 Comments

  • Cheryl Perry August 19, 2014

    Hi

    I’m having the same thing happen to me this year. Four years ago, I grew tomatillos from seeds with no problems. This year, i bought two plants instead of seeds. It didn’t take them long to have loads of blooms on them but then I started seeing the pin holes on what seemed like every tomatillo. So I made a spray from pureed jalapenos, cayenne pepper and water to use on the plants. It did not help at all. So I abandoned the plants because I never saw what was doing the damage.

    Yesterday, I went out to the garden and saw a few tomatillos that seemed undamaged so I got excited and picked them. Sifting through the hundreds of fruit on the ground, I picked up one and pulled back the husk and that was when I saw the worms burrowed in the tomatillo. I don’t know what kind of worm but they were short and striped.

    Does anyone have experience with this pest problem and are there ways to be more proactive for next year? I consider this year’s crop a loss. Any suggestions would be GREATLY appreciated!

    • Hi Cheryl,

      Don’t spray hot pepper juice on edibles! The plants can absorb it and altering the flavor of your harvest – an issue known to happen with pepper and garlic spray for deer repellents.

      Get some AzaSol. It isn’t cheap, but it does work on most plant pests, and is safe for organic fruit, nut, and veggie production. You’ll find it available from a handful of hydroponic shops online. Just price shop it. It goes a long way.

  • Linda Rendtorff July 23, 2015

    Try this: It might be that a bug lays its egg inside the tomalito, the egg hatches into a larvae which eats its way through the fruit and emerges as a nymph or adult which then goes through several instars (insect growth stages) to become the egg-laying bug, and it all begins again. If that is the case, you may only see the ‘worm’ while it is inside the fruit, not on the outside. Good luck, Linda.

    • Hi Linda,

      This possibility has occurred to us, but the tunnel has two openings – one of each end! The creature enters, crosses, and exits. There is no hollow spot where something grew in there. Just a thin little tunnel that goes straight through and large enough to let air in that spoils the entire fruit.

  • I had serious worm infestation with my tomatillos. I provided a couple of the worms to the local ag extension office and they were identified a tomatillo plant grubs. I used combination of perm-up and sevan to keep them under control. Got a lot of tomatillos. I have pictures of worms – both are less than an inch long. One is green with black stipes running on either side. the other is darker – more brown.

  • This is going to sound CRAZY… but we are in the middle of our annual asian lady beetle infestation around our house and I SWEAR – Truly -the Asian Lady Beetles are eating my tomatillos! I thought they must be digging after something – but I am finding them face first in the open cracks of the fruit (where they burst from over water and ripeness) – no other insects or eggs in the fruit, just asian lady beetles digging in. I don’t get it?

    • That is odd, because they don’t eat fruit – but maybe they’re there for some other bug? Like fruit flies if the tomatillos are super ripe and splitting open. If there’s one thing a fruit fly adores it’s a dead ripe tomato, and tomatillos are closely related.

  • Thank you for posting this. I am experiencing the EXACT same problem this year with my tomatillo plants, and now I am armed with a plan to combat the little buggers.

    • Hi Kristen,

      So glad to know I’m not the only person suffering from the invisible worm things destroying the tomatillo harvest. Hope the info helps you get the upper hand too.

  • Well, add me to the list……I’ve got these little buggers on my tomatillo plant as well. Thanks for the information everyone; reading the comments has been great. I am determined to make salsa verde from my backyard this year!

    • Hi Anna,

      So glad this page has once again helped someone. Salsa Verde, Roasted Salsa… there are just some things you cannot do without a pile of tomatillos!

      The AzaSol works great, and until you have it in hand, inspect the underside of all leaves every couple days for patches of those little orange eggs. Use physical pest control by smashing them between your fingers until you can spray for protection.

      Used this very method last year, and not one of the tomatillos harvested had those destructive tunnels!

  • I have never had problems with tomatillos no matter where I lived except for some flea beetles. Now living back in NM with almost an 1/8 acre garden and the potato beetles are terrible on my tomatillos. And I have had potato beetles before but never on the tomatillos. And I love my roasted salsa verde! Arrrrgggghhhh!

    • Hi Patricia,

      So sorry to hear you’re salsa verde is threatened. Arm yourself! Get some AzaSol. It works on many kinds of plant pests, and is approved for organic fruits and vegetables.

      Be sure to spray the whole plant – top and bottom surfaces of leaves.

  • Great site! Thanks! We have been able to identify our beetles with this info. We are in Big Bear City, California and never had these pests before we moved here. Here’s hoping for a good healthy harvest!

    • So glad the article helped you figure out a solution!

      Happy to hear you like our website. You’ll find lots of great info for your gardening efforts here.

  • I’m sorry no one was able to identify them for you yet. Most likely you have tomatillo husk worms, which are the same species as tomato fruitworms/corn earworms.

    You can treat them with Bt for moths which is far less likely to damage your pollinating bees than a broad spectrum pesticide (even an organic one). If it’s made to kill everything, that’s what it does, which leaves you as the sole protector of your plants because it takes out your pest’s enemies as well as the pollinators.

    Only 3% of insect species are pests, and most of the other 97% eat them. Additionally, pest insects are the “rabbits” of the entomological world in that their strategy to survive amidst so many predators is to reproduce like crazy so a few individuals pass on their genes to the next generation. This means a recently sprayed garden is a blank slate where the pests have an open window (usually half a growing season or more) to party hard destroying your crops before the predators show up and start eating them/reproducing their own kind to catch up. A mature organic garden full of biodiversity in plants and insects tends to balance itself out, but a new organic garden (especially in a neighborhood full of lawns or with a newly introduced vegetable that hasn’t had its pests & protectors show up yet) tends to have lots of problems. You reset to this “new” stage every time you spray broad spectrum pesticides instead of using targeted controls (or if your targeted controls are TOO successful and remove all the food for your predators.

    There are beneficial insects that will parasitize or predate your caterpillar eggs, larva, and adults,. However, they won’t come if there is nothing to eat, which means there has to be food present (aka, the pest) for them to build up their populations in your yard and keep it under control. Once they’re present, you’ll only lose a couple tomatillos instead of the bulk of them, which personally I find acceptable since I’m not having to spray all the time, spend money on pesticides, and happy tomatillos make more than I can eat anyway. You can achieve this by planting a sacrificial crop out of the way somewhere that you don’t try to control your pests on, by reducing how many you control (hand squishing is the best option here), or by sacrificing your main crop, which most of us aren’t interested in doing. Additionally, you need to ignore advice to sanitize your garden removing ALL the debris in the fall since your predators overwinter on the same materials as pests. Leave some winter habitat for your insect warriors.

    I also HIGHLY recommend planting flowers in the carrot (umbelliferae) and aster (asteraceae) families near your tomatillos (and other crops) because their blooms are beacons for the types of predatory insects you want. Herbs like cilantro, dill, and fennel are particularly excellent at attracting them. This is true of absolutely every crop that needs pollination or gets pest insect eggs & larva.

    Just make sure you deadhead the blooms once they start turning into seeds, because even though it still looks pretty to us at that stage, beneficial insects want a sip of energy-boosting nectar in between snacking on protein-dense pests and once the plant is making seeds it stops offering them this treat. Another good, inexpensive and fast-blooming plant for this is buckwheat allowed to flower. Good aster family options include zinnias and cosmos. You can use the dwarf ones if you don’t want them to crowd your veggies.

    The only pest insects I know of that don’t seem to have good predator controls no matter how long you use this strategy (on the southeast US coast at least) are harlequin bugs, leaf-footed bugs, and squash vine borer. I hand squish the first two or avoid growing the things the harlequin bugs like (mostly brassicas like kale/broccoli/etc.) in the hot months. It’s impossible not to grow things leaf-footed bugs like in the hot months. For squash vine borer I use Bt.

    If you’re interested in learning more about this type of pest control, look up the Living Web Farms videos on farmscaping, they’re great! I don’t usually leave long comments on old blog posts, but I’m a beekeeper and your comment on avoiding bee death sparked my interest. If my bees pick up a broad-spectrum pesticide in a garden and bring nectar it is laced with back to the hive to share, I loose a pretty big chunk of them (if it is something like Sevin dust stuffed into their pollen baskets it can even kill them all).

    Hope this helps. 🙂

    • Hi Eliza,

      Thanks much for all that information, but I’m doubting that they’re tomato fruitworms. The damage inflicted doesn’t follow their MO at all! It’s a pinhole entry and a tunnel that goes straight through the fruit emerging on the bottom or the other side. No big gnarly chewing destruction. Sometimes the entry and exit are so small you don’t notice them until the tomatillo is cut open.

      Not only that – but there are tomato plants, and lots of them, just across the main central row without any tomato fruitworm damage at all! Whatever it is is attacking ONLY the tomatillos.

Leave a Reply

Your email address will not be published. Required fields are marked *