What’s That Green Worm On My Tomato Plant?

 Wondering what the green worm is on your tomato plant?….

tomato horn worm with beneficial parasitic wasp eggs

Tomato horn worm with beneficial parasitic wasp eggs

Now’s the time to inspect your tomato plants closely for the presence of large green worms.  You’ll likely see foliar feeding damage or frass (poop) on leaves before you actually see the horn worm since it camouflages itself well among the leaves and stems.

If you do find them on your tomatoes and notice it covered in what looks like white rice, remove the caterpillar from the plant, but don’t kill it.  It’s covered with the eggs of  a beneficial parasitic wasp.  Consider yourself fortunate.  Soon the eggs will hatch and the larvae will feed on the host caterpillar.  It may sound disgusting, but the braconid wasp is one of nature’s beneficial predatory insects that are great at keeping pest populations in check.

If you find a tomato horn worm without the wasp eggs, feel free to pick it off and squash it, drop it in a pail of water or put it near your bird feeders (yumm).  No need to grab a spray can — they’re easily controlled.  But, be sure you get all of its siblings.  I like to keep a small jar with vinegar and a lid in my garden and scoop them in to go for a swim.

So far this year, though, I haven’t seen horn worms in my garden as I have a good population of beneficial wasps that I let hatch and multiply last season and they seem to be doing a nice job of patrolling for pests.

For more information on organic and Integrated Pest Management (IPM) strategies, call 908.309.6611 to speak with one of our Plant Health Care specialists or contact us at: OrganicPlantCareLLC.com/contact-us/

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Bill Grundmann

Bill Grundmann

Bill is the owner of Organic Plant Care, LLC. He takes an integrated approach to tree care, focusing not only on the trees themselves but also on the surrounding environment, managing tree health from the "ground up" - healthy soil equals healthy plants. Bill is a New Jersey Licensed Tree Expert and NJ Approved Forester with over 35 years of experience in the tree care industry.