As soon as the weather warms, everyone starts thinking about growing tomatoes. Biting straight into big juicy tomato, warm from the sun, the juice running down your chin and arm all tangy and sweet is something everyone should get to experience every year.
Sweet 100 cherry tomatoes are soo sweet!!
Even though the weather is getting too hot in the deep south for planting tomatoes, established plants are in high harvest time and those of you in cooler climates, where it’s still spring and are just getting started on tomato season, be ready. Nothing kills the tomato dream like armyworms!
We had a strike of the rascals last week and they are relentless! We try to stay vigilant, but couple days missed checking under leaves can be the decimation of an entire tomato plant.
So what is a tomato lover to do? Stay vigilant! You can beat these insatiable chewers with a little extra attention and some help from me!
What is an armyworm anyway?
Look at their voracious little faces!! SQUISH!
They are an insect found east of the rocky mountains in North America and in Central and South America, southern Europe, central Africa, and western Asia. Their Latin name is Pseudaletia unipuncta.
Armyworms are the larvae of a very unassuming nocturnal moth and got the name armyworm because they attack the plants with army size numbers of worms at a time. They also ravage oats, wheat, fall rye, corn, barley, bean, cabbage, carrot, onion, pea, pepper, radish, and sweet potato…to name a few!
How are armyworms identified?
Here is an adult moth. (Photo Credit: John Capinera, University of Florida)
The adult moth is a warm tan color and has about a 4cm wingspan. The upper wings have a small white dot on each near the lower center.
And this is just one leaf!! Who could even count them all, sooo tiny!! SQUISH!
Young larvae are identified by the sheer numbers of teeny caterpillars found on the underside of a leaf. Once they grow, they are identified by the striped pattern and reddish heads.
The stripes and red head are a dead giveaway for armyworm larvae. SQUISH!
Larvae also produce a silk when feeling threatened that they use to repel down back to the soil to hide. The larvae are mostly active at night and hide on leaf undersides, in curled leaves, or in leaf litter during the day. The pupae are in the soil, are about 5 cm wide, and of varying brown colors depending on the stage.
How can armyworms be prevented?
First and foremost, stay vigilant keeping an eye out for chew holes, curling leaves, fuzzy egg cases, and balls of poop on plants.
Poop right on the tomato itself. Some nerve!
Armyworms strike in the blink of an eye and there are so many in their army that you will be finding them for weeks after the primary attack. Silly me went out thinking maybe I’d find a couple leftover from the hatching we took care of last week. I killed about 50 just taking pictures for this post!
Snug as a bug in a rug all curled up in the midday heat. SQUISH Rascal!
Keep watch for the moths and kill any you find, if possible. If you have a bad infestation of moths, they make black light and pheromone traps that are said to work well, I’ve never used them personally. The adults drink the nectar of flowers and decaying fruit, so remove any dropped fruit from the garden bed.
Here is a case of eggs. Inside all the fluff are zillions of the little beasts! Thanks to this blog post I prevented this hatching! SQUISH!
Keep any leaf litter cleaned up from under plants to discourage safe hiding places for the larvae and pupae. Remove grass weeds from the garden as they are larvae attractors and look for egg cases on the undersides of leaves and destroy them. You have 5-10 days from when the moth lays the eggs until they hatch and begin ravaging. In climates with mild winters, the eggs laid in the fall can lay dormant in the soil and hatch in spring!
Also, plant and garden to attract birds and beneficial insects. If you’ve had a previous attack, apply beneficial nematodes to the soil to feed on any eggs, pupae, and larvae still lurking.
If they are found, how is battle with armyworm larvae engaged?
If you do find a hatching of armyworms, squish as many as you can immediately. Once you think you squished them all, keep looking (for a few more days/weeks) because there will be more.
Just munching away, all day and night. SQUISH!
Beneficial insects are always a good option in addition to squishing for bad attacks. You can release the teeny trichogramma wasps which parasitize the eggs, as well as release lacewings, ladybugs, and minute pirate bugs which will feed on armyworm eggs and larvae.
If adding more bugs seems like a nightmare to you, try a natural horticultural oil that includes Neem and/or Spinosad, both safe for organic gardening. When using sprays you must cover all sides of the leaves and stems and spray the soil surrounding the plant.
You can also dust the plants with Bt (Bacillus thuringiensis). This works well for chewing insects. When the caterpillars eat the dusted leaves, they are killed from the inside out, rather than the horticultural oil sprays which kill pests from the outside in by smothering them with the oil. Remember though, even natural organic insecticides have the potential to kill the beneficial insects, so they should be used as a final resort for severe infestations.
See how they skeletonize the leaf. Look for this sign and you will find them. SQUISH!
So are you ready? Don’t let an army or armyworms keep you from your sweet juicy tomatoes, crisp corn, or cool watermelons! Be ready, know what to look for, and protect your garden from the attack!
Have you ever had an armyworm attack? Share your experience below!
Show us pics of your juicy drippy sweet tomatoes and summer harvests on Instagram #wingswormsandwonder
Seeds to Sprout:
Learn more about armyworm zoology from the IFAS Extension
Learn how and why to build a trellis for your garden veggies here.
Have a school garden or just too hot for you to garden in the deep south all summer? Learn about cover cropping for summer here.