Tomato Hornworms - Don't Kill them

Tomato and Tobacco Hornworms

While these insects appear to be menacing and even dangerous, they are easily controlled and they provide an important role in your garden. Don't kill them! (yet)

Do I have them?

The first clue they are present was back in the late fall, when you dug up last years garden or stirred your compost pile and saw them in their equally menacing pupae stage. They look similar and are approximately the same size and the Japanese Beatle (a devastating pest) that will appearing later in the summer.

You might have noticed the egg of the worm in February when it appeared on the underside of a nightshade (yep, tomato and peppers kids) as a small white or light green egg about the size ball point tip.

The Beetle is easily controlled with the neem oil you have already been spraying. Hornworms LOL at your puny neem oil.

Worm Control

Equally, hornworms also scoff at your meager attempts to control with baking soda, epsom salt, diatomaceous earth, or soap. These fail equally and that is a good thing. Worms in this category are important hosts for a parasitoid wasp. These wasps infect and deliciously consume the worm. Then the wasps go on to find other hornworms. Win win! (spoiler at end of this page)

Revenge!

Right now this moth is in the worm stage of its life cycle. This is where we get our revenge!

If your hornworm has these rice like attachments it has been infected with a parasitic wasp. It is very unlikely that you will ever see this wasp, as they are very small. An infected worm should be valued and coveted. You should capture the worm on the stem (by cutting the stem near the worm) and drop the stem and the worm into a jar or bucket. Then give it a few leaves to eat. (crazy right?) For your efforts, the worm will be food. 

Its death (consumption) will be a benefit to your garden as it controls other hornworms, and its satisfyingly gruesome. 

In the End

Your garden is a place of life. All sorts of battles occur when you sleep, work, or garden. Some are within your control and some not. Wisdom is knowing the difference. Only You can make that determination. The Tomato Hornworm is a food source. It is part of the circle of life and all that. Like the aphid I wrote about it is a part of the whole equilibrium of life. 

Spoiler

If preserving the ugly scary worm for a small wasp to eat is not your bag, I can dig that. For 100% control of hornworms and all other worms from getting on your plants, you want Bacillus thuringiensis, commonly known as 'bt'. Bt can be found at your local garden center as Thuringiensis or Green Garden dust etc. Check the ingredients of the product.

attribution
http://extension.colostate.edu/topic-areas/insects/hornworms-and-hummingbird-moths-5-517/
http://www.harvesttotable.com/wp-content/uploads/2012/06/Parasitic-wasp-eggs-on-hornworm1.jpg