Is there a more adorable arthropod than the ladybug? From kindergartners to gardeners, everybody loves them. Here are 10 cool facts about ladybugs.
1. Ladybugs aren't really bugs at all, they're beetles!
Entomologically speaking, the term bugs applies to insects of the order Hemiptera. Ladybugs belong to the order Coleoptera, or beetles. Europeans have called these dome-backed beetles by the name ladybirds, or ladybird beetles, for over 500 years. In America, the name ladybird was replaced by ladybug. Scientists usually prefer the common name lady beetles.
2. The "lady" in ladybug refers to the Virgin Mary.
Legend has it that crops in Europe during the Middle Ages were plagued by pests, so the farmers began praying to the Blessed Lady, the Virgin Mary. Soon, the farmers started seeing ladybugs in their fields, and the crops were miraculously saved from the pests. They associated their good fortune with the black and red beetles, and so began calling them lady beetles. In Germany, these insects go by the name Marienkafer, which means Mary beetles. The 7-spotted lady beetle is believed to be the first named for the Virgin Mary; the red color represents her cloak, and the black spots represent her sorrows.
3. Ladybugs bleed from their knees when threatened.
A ladybug's hemolymph is both toxic and rank. Startle a ladybug, and the foul-smelling fluid will seep from its leg joints, leaving yellow stains on the surface below. Potential predators may be deterred by the vile mix of alkaloids, and equally repulsed by the sight of a seemingly sickly beetle. Ladybug larvae can ooze alkaloids from their abdomens.
4. A ladybug's bright colors warn predators to stay away.
Like many other insects, ladybugs use aposematic coloration to signal their toxicity to would-be predators. Insect-eating birds and other animals learn to avoid meals that come in red and black, and are more likely to steer clear of a ladybug lunch.
5. Over its lifetime, a ladybug may consume as many as 5,000 aphids.
Almost all ladybugs feed on soft-bodied insects, and serve as beneficial predators of plant pests. Gardeners welcome ladybugs with open arms, knowing they will munch on the most prolific plant pests. Ladybugs love to eat scale insects, white flies, mites, and aphids. As larvae, ladybugs eat pests by the hundreds. A hungry ladybug adult can devour 50 aphids per day.
6. Ladybug larvae resemble tiny alligators, with elongated bodies and bumpy skin.
If you're unfamiliar with ladybug larvae, you would probably never guess that these odd creatures are young ladybugs. Like alligators in miniature, they have long, pointed abdomens, spiny bodies, and legs that protrude from their sides. The larvae feed and grow for about a month, and consume hundreds of aphids or other insects during this stage.
7. Scientists believe ladybugs may lay both fertile and infertile eggs.
Why would a ladybug expend the energy required to produce eggs that will yield no offspring? The infertile eggs provide a ready source of food for the young larvae which hatch from the fertile eggs. When times are tough, a ladybug may lay an increased number of infertile eggs to give her babies a better chance of surviving.
8. Ladybug adults hibernate, usually gathering in large aggregations in protected places.
As days get shorter and temperatures fall, ladybugs seek shelter behind bark, under leaves, or in other protected locations. Thousands of ladybugs may gather in the same location, taking advantage of the collective warmth of a colony. Asian multicolored ladybugs, an invasive species in North America, has earned a reputation as a home invader. These beetles tend to move indoors for winter, where they can become a nuisance in people's houses. Convergent ladybugs gather in the mountains in such numbers that collectors can scoop them up by the bucket.
9. Ladybugs practice cannibalism.
If food is scarce, ladybugs will do what they must to survive, even if it means eating each other. A hungry ladybug will make a meal of any soft-bodied sibling it encounters. Newly emerged adults or recently molted larvae are soft enough for the average ladybug to chew. Eggs or pupae also provide protein to a ladybug that has run out of aphids.
10. You can't tell a ladybug's age by counting its spots.
The spots on a ladybug's back have nothing whatsoever to do with its age, fun as it may be to count them. In some cases, though, you can determine the ladybug's species by taking note of the number and position of those markings. The seven-spotted lady beetle, for example, has seven black spots on its red back.