It’s so exciting when you spot your first red tomato of the season. But when you see an armyworm caterpillar in your vegetable garden, there is no time to spare. They can devour a tomato plant in record time. They don’t discriminate. They will eat the leaves and the fruit, red or green. They don’t just attack tomatoes either — they can destroy most of your vegetable garden.
Armyworms can remain hidden from site because they hide in the shade of underside of the leaves during the day. Their larvae vary depending on the type of armyworm. There are three types of armyworms:
Western Yellowstriped Armyworm – These have bright yellow stripes running down the sides. Females lay eggs in clusters covered by a cottony-type material.
Beet Armyworm – These are pale green with light colored stripes that run down the length of the worm. The eggs are laid and covered with hair-like scales.
Yellowstriped Armyworm – These have two large and many smaller yellow stripes. The larvae are black.
Once you spot them there are five strategies for saving your garden, but act fast!
1.) Pull them off the plant and drop them in a bucket of soapy water, or stomp on them. Be sure they are dead, so they don’t just crawl right back into your garden. This can be a fun activity for kids in the garden.
2.) Spray your garden with Spinosad. This organic pest spray can kill a variety of worms and caterpillars and is safe to spray on food that will be eaten later. You can find spinosad based products at Amazon.
3.) Spread Bacillus Thuringiensis Dust (“BT”) – BT is not toxic to humans or animals and it may take a few days to work. Without giving you all of the gory details basically worms are no longer able to eat and they die. BT products are available on Amazon.
4.) Neem Oil – Neem oil will work for smaller worms and larvae but it won’t always work on larger worms. You can read more about neem oil in this article: Neem Oil General Fact Sheet. Neem oil can be irritating to skin and eyes, so be sure to wash any fruit that is sprayed. There are many neem sprays available on Amazon.
5.) Use natural predators in your garden. This can be a harder one to manage but birds and beneficial insects can destroy armyworms. Beneficial insects include ladybugs, lacewings and trichogramma wasps. The trichogramma wasps insert their eggs inside of pest eggs killing the larvae. See more about that in this article: Know Your Friends Trichogramma Wasps. You can purchase wasp eggs for your garden at Amazon.
Let us know if you have tried any of these and how they worked for you.
If you want to read more about armyworms see these articles below.