ColumbiaMagazine.com
Printed from:

Welcome to Columbia Magazine  
 

























 
Whitehurst diaries: Garden Journal/Tomato Hornworms

Tiny creatures are Gradyville gardeners' best friends. They incapacitate tomato hornworms, make use of their bodies for nurseries, incubating more wasps to control the tomatoc enemy>
Click on headline for full article plus photo(s)

By Sharon Whitehurst

Jim and I love to share photos of our garden. The garden triumphs, that is.

The first juicy sweet strawberries, ripe tomatoes, a bucket full of sleek green cucumbers - these all make good copy, with a subtle bit of [pardonable] pride involved.

What we less often share are the gardening failures - who wants to see a view of a zuchini plant which has just succumbed to an invasion of vine borers.


I've learned more about tomato wilts and blights in the past few days than is good for my spirits. [Who knew there exists "early blight," "late blight" and, oh joy, "Southern Blight!"]

Matt and Gina have been here today working on the strip of garden they planted while waiting to move into their recently purchased house down the Old Gradyville Road.

Matt presented me with the creature I recognize as a tomato hornworm. After insisting that he squash the thing, I deserted the green beans waiting in the kitchen sink and did some research.

The following is by Timothy J. Gibb, Insect Diagnostician, Department of Entomology, Purdue University:
Finding a large green tomato hornworm caterpillar on your tomato plant is never a good sign unless, that is, it has small white capsules attached all over its back.

The white capsules on its back, frequently mistaken for "hornworm eggs" are actually the pupal stage of a tiny wasp called a Braconid.

As Braconid larvae, these wasps fed on the insides of this hornworm and have now completed that feeding and are preparing to emerge as tiny wasps.

Under such circumstances, the hornworm caterpillar might be capable of slow sluggish movement but is incapable of further feeding and will die very shortly.

In the meantime it serves a very valuable function as a nursery for these wasps. When they emerge, the adult wasps will fly off to hunt for other hornworms to parasitize.


So, if you leave the parasitized hornworm in place and allow the parasites to emerge, you are in effect killing many other hornworms in the vicinity.

I call this good luck! Timothy J. Gibb
It appears that while the tomato worm is bad, the attached eggs might just serve a useful function. -Sharon Whitehurst


This story was posted on 2011-07-06 14:47:35
Printable: this page is now automatically formatted for printing.
Have comments or corrections for this story? Use our contact form and let us know.


To sponsor news and features on ColumbiaMagazine, please use our contact form.

When a tomato hornworm is welcome sight



2011-07-06 - Old Gradyville RD, Gradyville, KY - Photo by Sharon Whitehurst.
Sharon Whitehurst says a tomato hornworm in this condition is a welcome sight - when it's covered with the larval stage of tiny braconid wasps, which use the tomato hornworm for an incubator and make it too sluggish to continue its damaging feast on tomatoes.

Read More... | Comments? | Click here to share, print, or bookmark this photo.



 























 
 
Quick Links to Popular Features


 

ColumbiaMagazine.com content is available as an RSS/XML feed for your RSS reader or other news aggregator.
Use the following link: http://www.columbiamagazine.com/columbiamagazinerss.php.

Contact us: Columbia Magazine and columbiamagazine.com are published by D'Zine, Ltd., PO Box 906, Columbia, KY 42728.
Phone: 270-250-2730 Fax: 270-751-0401


Please use our contact page, or send questions about technical issues with this site to webmaster@columbiamagazine.com. All logos and trademarks used on this site are property of their respective owners. All comments remain the property and responsibility of their posters, all articles and photos remain the property of their creators, and all the rest is copyright 1995-Present by Columbia! Magazine and D'Zine, Ltd. Privacy policy: use of this site requires no sharing of information. Voluntarily shared information may be published and made available to the public on this site and/or stored electronically. Anonymous submissions will be subject to additional verification. Cookies are not required to use our site. However, if you have cookies enabled in your web browser, some of our advertisers may use cookies for interest-based advertising across multiple domains. For more information about third-party advertising, visit the NAI web privacy site.