Friday, May 6, 2016

The Eastern Tent Caterpillar

Have you spotted this guy? He should be among America's Most Wanted. It's the Eastern tent caterpillar, or Malacosoma americanum. My entire garden is overrun with them. Here's how to control the Eastern tent caterpillar.

That's him. Sneaky little insect. This spring, we noticed the start of what turned out to be quite a swarm among our fruit trees. Normally, we see the sticky tents, or webs, of the tent caterpillar on the wild cherry trees along the forests and roads here in Prince Edward county. But I have never seen them marching across lawns, over piles of construction materials, and even into my garage!

The tent caterpillar is a native insect found throughout the entire Eastern region of the United States. It is most obvious when it's in the sticky tent, or web, that you're probably familiar with in the crotch of trees or on the forked branches of your favorite cherry tree.

The female moth lays a cluster of small, shiny black eggs in the fall or early spring. The young quickly hatch into larvae, and the larvae or caterpillars spin a sticky web around them. They cluster together in the middle for protection.

Three or four times a day, the young emerge from their nice snug little nest to feed on the leaves of the host tree. They can strip the tree of all of its leaves before they're done. It doesn't kill the trees outright, but it does stress them considerably, as you can imagine. The tree must grow an entire new set of leaves.

"Hello, there! Thanks for the peach tree leaves! They were delicious!"

The young expand their sack or tent until they are ready to pupate, or turn into moths. They emerge fro the sack and begin their migration. That's what I am seeing now all over my yard. The swarms of tent caterpillars are simply individuals looking for a nice spot to spin a cocoon and emerge in a few weeks, moths ready to fly away and continue the cycle.

I don't know if any other parts of Virginia or areas served by the Heart of Virginia Master Gardeners are also seeing a surge in tent caterpillars. According to the Cooperative Extension website, there's a natural fluctuation from year to year in the population.

Natural predators include birds and predatory wasps, and in a quiet year, that's who keeps them in check. Some years, like this one, we just seem to have more.

To control tent caterpillars, you've got to be brave. Put on a pair of rubber gloves -- the kind you use to keep your hands clean while you scrub the toilet. You know the kind I'm talking about. Then grab a pail or bucket. Pick off the caterpillars and drop them into your bucket. The "squish" method works well. You can also use a trowel to chop them in half or squish them on the tree. It's gross, I know, but the most effective way to get rid of them while they are out of the tent.

If they're in the tent, take a garden rake or hoe and use it to reach into the branches of the trees to remove the nest or tent.

Sprays, according to the University of Kentucky and Missouri websites, have little effect upon these critters (lucky them.) If you'd like to learn more about what sprays do work, please review the information on their websites:

1 comment:

  1. I have seen the usual number in my neighbor's tree. 30 feet high or more. It's a big tree that usually gets about 3 or 4 colonies or tents a year.