The garden’s a mess. Torrential rains, followed by extreme heat, kept us back from some of the work we might have done to keep it tidy at crucial times. Plants are sprawling all over each other, “rows” have run together, and some of the weeds are sky-high.
It doesn’t seem to be interfering with our harvests, for the most part. Okay, I lost half a row of leeks under some overgrown arugula that fell over on them in a windstorm, because I hadn’t taken the time to pull it out when it was essentially past its prime. And then I didn’t find the time to pull it off the leeks until it was too late and they were collapsed and rotting beneath it.
But there is an up-side to the disorder - we are seeing record numbers of beneficial creatures and insects. For several weeks now, it’s been rare to harvest something without finding a praying mantis patrolling the veggies, or frogs jumping out of my path. And recently, while examining for tomato hornworm damage, we found this:
Interrupted right in the middle of breakfast! A hornworm, covered with pupating wasps, right above the bite-marks it left in the tomato leaf...
Under the cottony white packages, there is a green caterpillar with a red spike on its butt - a tomato hornworm, a fantastically destructive creature. They blend in perfectly with tomato stems, and are difficult to see until you notice the damage. By the time you notice the damage, there’s a lot of damage to notice. One worm will have defoliated half a tomato plant, bitten into the developing fruit, and lopped off the replacement buds. But - they have a predator that stops them in their tracks. This hornworm is hosting a nice clutch of parasitic braconid wasp cocoons.
The wasps are small, and their cocoons are the tiny white wooly packages dotting the top of the hornworm. Those aren’t part of the hornworm. The description of what the wasps do to the hornworm reads like poetry to the organic farmer who has picked her share of hornworms off by hand, and endured their rampages. In short, the wasps lay eggs in the caterpillar, the larvae feed off the caterpillar’s innards, and hatch out through to its surface to form their cocoons and finish pupating. Here’s a more descriptive page about it.
Nearby, there was a second parasitized hornworm. The hornworms were literally stopped in their tracks, beside the chewed up leaf they’d been feasting upon. I watched them for a few days - they were always in the same location, not dead yet, but obviously sick and not moving, and most importantly - not eating!
Last summer, we had record numbers of hornworms, but I found only one of these parasitized hornworms, with just a few cocoons. I carefully watched that one, and left it in its place. If you find one of these, don’t remove it!! The hornworm is a goner, even while still alive, and you can leave it alone without fearing it will continue to do damage. It’s important to leave it so the wasp larvae can complete their hatching and become more wasps that can kill more tomato hornworms. This year we have had radically less hornworm problems, and at least double the sighted evidence of braconid wasps.
The wasps are tiny, cute even, and harmless to humans. They are part of why I won’t put anything harmful on my garden. Not anything. Not even the organically-sanctioned treatments. I may have garden chaos, I may lose some things to pests, and I may have holes in some produce. But we also have an environment. We have a mini-ecosystem keeping its own checks and balances. What I use in the garden to kill the caterpillars will also kill or affect the wasps. And the bees, and the mantises, and the other pollinators and predators. Not cool, not what we want, not why we are doing this. The frogs, the mantises, the parasitic wasps, the spiders, and the assassin bugs that find a home in our jungle garden have taken several years to make their way there, and they are integral to the way our garden works.
So the besieged caterpillars stayed on the tomato plants for a few days, until one day they were gone, probably dropped to the ground dead. I noticed only when I could zoom into the photo while editing, that the little wasps had already hatched from one of the clutches when I photographed it:
Their cocoons have their hatch doors popped up, and the cocoons are empty. Another tiny army of protectors is out there already, patrolling for us, finding the hornworms we won’t see.
