Ladybugs are one of the few insects everyone seems to love. They come in many colors, shapes and sizes. In fact, there are more than 450 different species found here in North America. Most people know they are good for the garden, but have you ever stopped to wonder why?
Some species of ladybird beetles congregate in masses during winter to hibernate.
Ladybugs come in many colors. This is the pink spot ladybird beetle, Coleomegilla maculata.
Photo Credit: ©2005 Buglady Consulting
Ladybug larvae don’t look like adult ladybugs at all, but they’re just as beneficial to have around. The best way to get larvae in your garden is to attract adults, which will lay the eggs.
Photo Credit: ©2005 Buglady Consulting
While not all its spots are visible in this shot, the seven-spotted ladybird beetle, Coccinella septempunctata, can be identified by its polka dots.
Photo Credit: ©2006 Buglady Consulting
Ladybugs, or ladybird beetles, are “generalist predators.” This means they feed on a wide range of insect pests and mites (sometimes they even eat the other good guys). As the adult and immature ladybugs wander through your garden and landscape, they’ll eat just about anything in their path.
Because many of today’s gardeners want to control their pests naturally, they’re turning to these little friends to eat away garden pests. Many people are buying adult ladybugs at garden centers or over the Internet to release at home.
Where do these ladybugs come from?” Most ladybugs for sale are the convergent lady beetle, Hippodamia convergens, and sadly, they’ve been “harvested” from natural winter aggregation sites.
What does this mean exactly? Well, in the western United States, after the ladybugs have fed all summer, they head up into the mountains by the millions to spend their “off season.” While resting clumped together by the thousands, collectors come along and scoop up the hibernating ladybugs. Next, these dazed beetles are either packaged and shipped out to retailers or they’re held in refrigeration to break their hibernation. If they aren’t held to “break” their hibernation cycle, they won’t lay eggs when released. This dormancy stage must be broken for the life cycle to continue.
If you do purchase wild-harvested ladybugs after they’ve had their dormancy broken, what will happen? Most of the time once they’re released, the beetles migrate before starting to feed or laying their eggs. In most cases, they’ll migrate right out of your garden. Unfortunately, this means little or no control for your pests.
Another concern is that harvested ladybugs may have been parasitized by a small wasp called Perilitus coccinellae. The wasp develops as an internal parasite, killing the ladybugs. There is no test for the parasite, so you may inadvertently be adding them to your garden when you buy your ladybugs.
The short point here is that purchasing wild-harvested ladybugs, which almost certainly what you will find at retail outlets, will not do much good for your garden, and it may introduce non-native species into your local ecosystem. Additionally, purchasing these ladybugs may contribute to the decimation of the wild ladybug populations. This is an unfortunate situation because some collectors are taking advantage of an opportunity to literally pick money (the ladybugs) from the landscape, and they don’t see the longer term consequences. If more people know about this reality and stop purchasing wild-harvested ladybugs, this problem can be stopped.
How can you control your pests naturally without buying ladybugs? There are other beneficials you can purchases that are reared in labs – like green lacewings or minute pirate bugs. Or you can use plants to attract your native beneficials, and they’ll do the pest clean-up work for free.
Ladybugs are great to have in the garden to help control your pest problems, but it’s best to let your local ones do the work for you.