The Aphid vs. Ladybug Saga Continues


So we’re about 10 days out from releasing our first batch of ladybugs into the greenhouse to deal with our aphid infestation. We released approximately half the first day, and then we’ve been slowly releasing a few more at time every couple of days.

Things were looking good, within just a few hours there was a marked difference in the number of aphids on the seedlings. We were optimistic that 1000 ladybugs had solved our aphid problem. A week out, we’re not so sure…

We made a shroud of tulle fabric that we had in the sewing room to try and keep the ladybugs from escaping the greenhouse so quickly. At first we just had it hung over the door of the greenhouse. Then we moved it so if hung straight down to the floor over the entire length of the shelf of plants. It worked ok, but plenty of them still found their way out.

They did pretty well, within a few days the Dracaena seedlings were almost clear of aphids. We’re still not positive if they’re all going to survive since the aphids did so much damage before the ladybugs arrived. Most of the other seedlings in the greenhouse are doing ok now too, they seem to be mostly clear of aphids.

But, the petunias, which had the worst infestation to begin with, are still not out of the woods. At first it was looking optimistic, like everything else. But a few days after the rest were looking good, we noticed more leaves on the petunias that were loaded with aphids again. So we’ve sort of isolated them from the rest.

We moved them up onto the top shelf, and completely shrouded them in the tulle. The tulle is wrapped around, underneath all the trays, up to a bar above the trays, and then around the ends too. We’ve got it clothes-pinned together to seal off the exit opportunities as much as possible. Every few days we add a few more lady bugs in and close it up quick. A couple of days ago we released the last of them into the shroud.

The bag says that in 7-10 days we should be seeing ladybug eggs and nymphs. I haven’t seen any yet, but that doesn’t mean they’re not there. Either way, I hope they pretty much take care of the aphid problem soon, so our petunias don’t all die.

It’s clear we’re going to lose some of the seedlings, there is a few here and there that are in pretty rough shape. I’m just hoping that the one batch of 1000 aphids will be enough to get our little baby plants through until they are a little stronger and can be moved outside.

I feel like I need to add a note about the much-discussed efficacy of ladybugs. If you google live ladybug suppliers, as I did, you’ll mostly likely come up with a long list of articles about “why you shouldn’t buy ladybugs for aphids.”

I’ve previously mentioned that I think these articles are a bunch of BS. But after thinking some more I realized that in a broader garden they’re probably right. Ordering 1000 ladybugs and releasing them over my entire yard/garden would be an exercise in futility. 1000 ladybugs free in my garden is 1000 ladybugs free in my entire city, they would disperse quickly and have very little impact on my yard or garden as a whole. We have a more controlled environment, a small greenhouse, with the ability to control their movement somewhat with fabric and release them slowly over time.

So, if you have an aphid problem in your yard, I probably wouldn’t recommend ordering ladybugs to deal with it, unless of course you want to order 100,000 or something. But if you have an aphid problem in your house, or in a greenhouse, or even a cold frame, it might be worth a try.