Bugs in Balance
- Solstice P-Patch
- Jul 3, 2021
- 3 min read
Updated: Jul 24, 2021
Updated 7/24/2021
It's very likely that our tiny guests, the little lacewing larvae, hatched within a few days given how warm our weather has been. These larvae are so tiny they cannot be seen with the naked eye. Normally they eat for 2 weeks before forming cocoons and eventually turning into the adults, who will then lay more eggs.
Unfortunately in some areas of the patch we're seeing a big enough of a pest infestation that it's likely the population was already too well established for the lacewings to handle. Arbico Organics recommends spraying for now. If you're seeing whiteflies in your patch you could use Neem Oil and spray it on the underside of the affected leaves (but early in the morning or in the evening - not in hot sun). Another option is a new product called Purecrop1 that doesn't hurt beneficial insects.
Original Post:
Earlier this week, Sandra gave the P-Patch a heads up about a couple problem insects in the patch - whiteflies and aphids - and the use of Green Lacewings to help manage the problem. Today, we’re writing to share a bit more information!
Though there are hundreds of whitefly species, only a few of them seem to bother vegetable gardens. They aren’t picky eaters, so you might see them on a lot of different plant types. That said, in our garden, they seem to be drawn to plants from the cruciferous family—such as your kales and broccolis. My poor Dino kale has quite the healthy whitefly population, unfortunately. One way to tell if you have them is to gently wiggle the leaves of some of your plants and they will fly off the plant temporarily. Or, you can look on the underside of your plant leaves. This is usually where they rest and lay their eggs, which look like small white smears on the underside of the leaves.
A few whiteflies probably aren’t a big deal, but if there are too many, they can damage plants through their feeding or by passing diseases on to plants. Normally, their population is managed by predators and especially by the cold weather in the winter season. Unfortunately, this past winter wasn’t very cold – likely explaining why we have an infestation this early in the summer.
Solving the whitefly problem
We can take a number of approaches to address the whitefly problem, though per the P-Patch Program Guidelines, all measures need to be organic. The leadership team approved a request to purchase Green Lacewing eggs from Arbico Organics. Once hatched, the beneficial insect larvae will gobble up the whitefly eggs and larvae. You can view pictures of the eggs and insects on the Arbico Green Lacewing information page. Lacewings also eat aphids, leaf miners and other soft-bodied insect pests – an added benefit of having them in the P-Patch.
The eggs were placed in the P-Patch on July 2 in several plots where whitefly, aphids, and leaf miners were observed. Those gardeners have been notified and asked to avoid overhead watering for at least ten days, so the eggs are not washed off. We will be monitoring their progress. If it looks like they are effective, but the whitefly problem persists, we may consider ordering more eggs. Eventually the current eggs will become adults and start the life cycle over again, so hopefully we will have the lacewings long-term in the garden.
We Can All Help!
Take a look at what Green Lacewings look like and give them a nod of thanks when you see them!
For the next few weeks, please refrain from using pesticides in your garden so that we can give these Green Lacewings a chance at success.
Remove heavily infested parts of plants (leaves) and dispose of them – not on the weed pile please! Put them in a plastic bag and take them home or down to the garbage can at the tennis courts.
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