This is Really Bugging Me...

I'd like to promise that this will be my last post about insects, but that would probably be unrealistic.  After all, there are so many of them and so few of us. In fact, the actual number of them isn't known, but there are reliable estimates* that there are some 10,000,000,000,000,000,000  (Ten Quintillion) currently alive; about 1 million species identified, and perhaps as many as another 30 million not yet discovered.

That's an awful lot of bugs.

So I guess it's understandable that creepy crawly hijinks appear frequently in this blog.  And it's also probably understandable that, given how many different kinds there are, I'd occasionally mis-identify one.  So I'm starting this item with an apology.  In an earlier post (In Fragrante Delicto)   I captured a close-up of what I described as "an enraged hornworm:"

Well, he was enraged alright, but he was no tomato hornworm.  I still don't know what this expressive critter is (apart from fat and destructive), but I can say with certainty, it's NOT a hornworm because after keeping my eye out for others of his ilk on the tomato plants all summer long, I finally saw the telltale damage that indicated the dreaded insect had arrived.

Tomato leaves stripped bare

Following the evidence trail of naked stems led to an uneaten leaf covered with shot-peen sized balls of caterpillar poop -- scatalogical evidence that directly above the deposits, camouflaged somewhere on the tomato stems, was the culprit.  A careful inspection revealed this bad boy:

The real deal tomato hornworm

It's hard in this close up to really appreciate how effective the camouflage is.  This particular specimen was BIG -- a good four inches long and a plump half inch across.  Unlike its evil non-twin, the horn is on the butt end, not the head end of the hornworm -- and if you poke it, unlike the false hornworm above, nothing interesting happens.  And these guys can EAT.  It seems that they can go from almost nothing to supersize in a day; they can certainly strip half a tomato plant in that time, so it's imperative that once you see the signs of damage you find these suckers and dispatch them with no mercy.

Here's another one, about to attack a defenseless tomato frond

The day I found the damage, I also discovered that Mother Nature has a truly perverse streak.  After picking off 3 that looked like the blimpos above, I came upon a truly amazing sight.  It was another of these hornworms, totally covered in what looked like miniature rice puffs. In all the years I've hunted hornworms, I've never seen anything remotely like this.

Mr Mulch, being more familiar with the insect world from years of tying his own flies, said that he thought they were parasites of some sort and that they might represent nature's way of dealing with these pests.  And he was absolutely correct!  I asked The Google for details and here's what I found: 

• A natural predator of the tomato hornworm is a tiny beneficial insect called the braconid wasp. This wasp lays its eggs inside the hornworm. As they hatch, they eat their way out, killing the hornworm in the process. It's a bit off-putting to see this creature on your plants, but you're better off letting him be and letting the wasps do their job. Once they hatch, they'll be enough braconid wasps to keep your garden hornworm free.

"A bit off-putting" is a bit of an understatement!  It's downright gross to find a ravenous caterpillar, revolting enough in its own right, festooned with mini Rice Krispies which are busy eating their host from the inside out!  And if this is Mother Nature's way of controlling the population of a garden nuisance, one wonders why, if this wasp lives only to kill hornworms, we couldn't have skipped both species entirely and given the tomato plants one less thing to deal with!

In the meantime, I now know that it's best to leave alone the hornworms with the parasites on them -- they'll get their just dessert in good time -- but I'm still going to remove them from the tomato plant because they certainly don't deserve a last meal.

Evicted tomato hornworm awaits his fate

And if anyone can tell me what the caterpillar is that I mis-identified originally as a tomato hornworm, I would really appreciate it!




*Attributed to Pulitzer Prize winner Dr. E.O. Wilson of Harvard