Nature’s own pest control


I was watching a few back episodes of Gardener’s World the other day (I have it on series record and occasionally catch up with Monty and his dog Nigel pottering around his garden – I find it quite relaxing) and I was fascinated by the latest episode with wildlife photographer Simon King. He had a nest of tree wasps in his garden and told us that wasps are brilliant pest controllers, eating (among other things) caterpillars. Ah ha! I had to rewind a couple of times to make sure I hadn’t misheard that.

Firstly, I always wondered what wasps were good for, and secondly, I knew something must be eating the caterpillars on my purple sprouting broccoli.

I initially had the plants under cover to stop the pigeons stripping them bare (as they did last year) but when they got to a couple of feet tall, they started pushing upwards against the small net tunnel, desperate to be free. Unfortunately though, I had no other netting large enough to cover them. The netting I used last year has strangely disappeared, and the calabrese are using my huge piece of environmesh for protection. So I reluctantly set them free to the elements and the local wildlife, with the plan to either get some more netting, or look into biological controls for caterpillars.

caterpillar eggs

Needless to say, I kept on forgetting to do either. I just kept squishing any eggs I came across and hoping for the best. Then I noticed a bad attack of whitefly, and reached for the organic pest spray that I only use as a last resort. But, before I had a chance to spray, I noticed a ladybird on one of the leaves and it stopped me in my tracks. Thankfully.


I also realised that there were actually very few caterpillars. Considering I only visit the plot around once or twice a week, my egg squishing efforts couldn’t be that effective. I wondered whether birds were visiting and eating them.

So after watching him on TV, Simon King got me wondering about wasps. We didn’t seem to see many wasps last year, but have noticed a few around just lately. Maybe the hot weather has been better for them this year? So on my latest plot visit, I had a little look at my plants. I initially couldn’t find a single caterpillar, plenty of eggs and a few leaves have been well nibbled, evidence that caterpillars have been around. I spotted a couple of ladybirds who are gradually hoovering up the whitefly, brilliant, and then after just a few minutes, wha’d’ya know, a wasp.


I had to double check I hadn’t mistaken it for a hoverfly or bee, but no, definitely a wasp. I’ve never been so excited to see a wasp before. And then his mates showed up, non of whom were too impressed with my camera antics, so I had to stand back for a while to give them access. Sorry lads, in you go! I just about managed to capture one as evidence.

They didn’t hang about for long, they swooped in like a fleet of military helicopters from Apocalypse Now. The Ride of the Valkyries should have been playing in the background somewhere. They didn’t land on any leaves but expertly glided in and around the leaves, going from one plant to the next, seeking out the scent of caterpillar (as opposed to napalm), and after deciding there was nothing to be had, they were off to check out the next joint.  Quite scary, I imagine, if you’re a tiny wee caterpillar. I know grown humans who are afraid of them, well imagine if you are this size …


… and they’re going to eat you alive or feed you to their babies, rather than just slightly annoy you by trying to get in your beer glass. There was a wasp nearby when I spotted him, and I was willing the wasp to find him, not for any gruesome viewing, but just to confirm my theory. It didn’t happen. I’d put some grass clippings down as a mulch under the plants, so maybe the fresh grassy smell was confusing things. Mr hungry caterpillar was wiggling about, nose in the air, ‘is that … is that a WASP I can smell?’ More likely it was me. I’m actually starting to feel sorry for the caterpillars now. It’s a harsh world. But at least my plants are safe! My ‘organic’ pest control spray is going in the bin, who needs it.

Please don’t use chemicals on your crops. Through watching and observing on my allotment, I have learnt that there’s a whole ecosystem at work, even if you don’t see it, and it’s fragile and we need to take care of it, and in return, in time, it will take care of your plants if you just allow it to.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s