Almost everyone likes seeing ladybugs in their gardens. We welcome these tiny insects because we consider them good bugs, or beneficial insects, creatures that eat the insect pests that eat our plants. What we refer to as ladybugs are not actually true bugs, but beetles. Bugs are a separate classification of insect entirely, so entomologists prefer the term lady beetle (or ladybird beetle) to avoid confusion.
Here are a few ladybug-related facts to marvel at as you watch them scurrying around your plants this summer:
There are about 5000 species of lady beetles in the world, about 450 species native to the U.S. Most eat other insects, but some can be pests of agricultural crops, such as the Mexican bean beetle and the squash beetle.
Lady beetles largely prey on aphids, scales, mites, and fruit flies, laying their bright yellow eggs right among these pests, so their offspring immediately have something to eat once they hatch. The worse an aphid infestation, the more lady beetles around. When the aphids are gone, lady beetles fly away to look for the next meal.
The larvae look nothing like adult lady beetles. In fact, they look like little black and orange alligators. Depending on the species, lady beetle larvae can eat hundreds of aphids a day, while adults eat about 50 aphids per day.
Adult beetles also eat nectar and pollen, and are attracted to the flowers of chives, cilantro, dill, marigold, sweet alyssum, and yarrow.
Using pesticides in your garden to kill pest insects can harm lady beetles as well.
That bright red color is a warning to predators to leave lady beetles alone. Their joints emit a liquid that tastes bad to predators (and can stain fabric when they get indoors). That said, some spiders and stink bugs do eat them. Lady beetles can also bite, but that's not a first line of defense.
The number, size and shape of the spots on a lady beetles' back differs among species. Some lady beetles have no spots, and some have stripes. Lady beetles can also be orange, yellow, black, even pink.
Native lady beetles are being squeezed out by non-native species, including the Multicolored Asian lady beetle (Harmonia axyridis). These are the ones you see clustered on outside walls in autumn, looking for a place to overwinter. Native to Asia, they were introduced in the States starting in 1916 to help control aphids in pecan orchards. They settled in, and have been here ever since.
The lady beetle is the state insect of Delaware, Massachusetts, Ohio, New York, New Hampshire and Tennessee. In some cultures, a lady beetle landing on you is considered good luck.
Contributor bio: Therese Ciesinski is editor of GardenSMART's In The Dirt newsletter and a freelance writer whose articles appear in Garden Design and Coastal Home magazines. While an editor at Organic Gardening magazine, her writing received a Gold and six Silver Media Awards from the Garden Writers Association. She has also written for Houzz.com,This Old House, and Green Scene magazines.
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