If you’re an organic gardener, you probably know that lady beetles (aka ladybugs) play an important role in controlling aphid pests. Adult lady beetles, and more especially their young larval form, vacuum up hundreds to thousands of aphids during their life span. But did you know lady beetles also prey upon small pest caterpillars?
Check out this larval lady beetle working on a Cabbage White Moth caterpillar who (along with several dozen of his brothers and sisters) was devouring our Brussels Sprout foliage:
So if you see one of these alligator-like red and black larvae crawling around on the leaves of your plants, don’t panic! They are baby lady beetles. Leave them alone and let them do their work.
Just one of the many reasons we never spray insecticides here! Spray the bad guys, and you’ll nail the good guys too…and once the good guys are gone, the bad ones tend to come back with a vengeance…
You can buy Lady Beetles to release into your gardens, but I wouldn’t bother. Here’s why. If you buy packaged lady beetles, they are more than likely going to be Asian lady beetles–imported for crop pest control–which have become something in a nuisance in New England for invading houses in the fall looking for a winter home (and causing an allergic sting to some people). And as it often happens, importing a foreign insect introduces unwanted consequences — not only do they introduce foreign diseases and parasites that impact the indigenous species, Asian lady beetles are highly cannabalistic and feed upon the native species with gusto. Will the native lady beetle species disappear completely over time as a result?
(Asian Lady beetles tend to be larger than our native lady beetles, and often have more spots. Click here to learn more about the difference between Asian and native lady beetles)
So, to attract and support beneficial lady beetles, your property should supply food for both the adults and the larval form. Flowering nectar plants supply the adult beetle with the energy it needs to fly, so include a variety of plants that bloom through the season such as coreopsis, phlox, nepeta, asters and other daisy-like composite plants. Grow culinary herbs such as oregano, thyme, cilantro, dill, parsley, basil, common chives and garlic chives (pictured), allow some of them to flower to attract the adult beetles.
As for the larvae, adult lady beetles lay their eggs on plants known to attract aphids and other soft-bodied pests, knowing that there will be plenty of food for their offspring once they hatch and begin to feed. If you’re a gardener, and you don’t spray insecticides, you’re most likely already there…
Pictured at right: A juvenile lady beetle, gobbling up aphids on the back of a milkweed leaf. You can see this one has almost reached its adult form. Milkweeds are prone to aphid attack, but try to think of them in your garden as effective lady beetle habitat!