ISU Extension News

Extension Communications
3614 Administrative Services Building
Ames, Iowa 50011-3614
(515) 294-9915


Donald Lewis, Entomology Extension, (515) 294-1101
Elaine Edwards, Extension Communication Systems, (515) 294-5168

Yard and Garden Column for the Week Beginning May 14

Ants, Bees and Ladybugs - Old Legends Die Hard

By Donald R. Lewis
Extension Entomologist
Iowa State University Extension

Everyone believes some facts that aren't true. We think we know something to be true only to discover that it is an urban legend, a folk tale, just a rumor or worst of all, a hoax.

This is certainly true for insects. A great deal of folklore about insects passes for fact but is actually misinformation. While most of this misinformation is harmless, it is still a good idea to know the truth.

For example, do you subscribe to the popular notion that ants must be present for peony blossoms to open? It seems logical enough, but there is no truth, whatsoever, to the long-standing, widespread and oft-repeated folk tale that ants are essential for the normal opening of peony flower buds.

It is true that there is a special relationship between ants and peony buds. However, the relationship is the reverse of what the folk tale claims. The peonies don't need the ants, but the ants do take advantage of the peonies!

Peony buds have very small extrafloral nectaries (special glands that produce nectar) along the outside edges of the scales that cover the developing buds. Ants devour this mixture of sugar, water and amino acids in what may resemble a feeding frenzy. In exchange for the free nectar, the ants drive off pests that might nibble on the buds. But rest assured that the peony flowers would open normally and on time even without ants walking across the surface of the bud.

Bumble bees can't fly

Of course, bumble bees can fly. But if you are like most people, you have heard (and maybe believed) the legend about an engineer that proved it was aerodynamically impossible for a bumble bee to fly. Bah, humbug!

There are several versions regarding the origin of this myth. The generally accepted version has it that the calculations were speculations overheard by a member of the media during a reception. Once the story was printed, it slipped into our collective memory banks. Unfortunately, less attention has been given to the retraction that was issued almost immediately. The retraction didn't make it into the papers, the damage was done and an urban legend was born.

Luck and ladybugs

An enduring and nearly international insect belief is that finding a ladybug brings good luck. This myth might not be all wrong. Since ladybugs eat aphids, other small insects, mites and the eggs of insects and mites, you could argue that ladybugs do bring good luck to farmers and gardeners. However, there is no evidence to prove that the good luck extends beyond the benefit of fewer aphids feeding on your plants.

What about a ladybug's spots? An old myth states that you can tell the age of a ladybug by counting its spots. Balderdash!

There are more than 5,000 different species of lady beetles (ladybugs) in the world and approximately 475 species in North America. There may be as many as 100 different kinds in Iowa.

The numbers and arrangements of spots on the backs of ladybugs are distinctive for the different species. The number of spots on ladybugs likely to be seen in your backyard varies from zero to 19. Again, the number is "fixed" for each species; that is, once a lady beetle emerges it never changes its spots.

In case you're interested in ladybugs, here is a list of the names of the most common species and their number of spots. I think you'll see an interesting pattern that tells you a lot about the imagination of entomologists who give names to things.

Convergent Lady Beetle (13 spots), Twelvespotted Lady Beetle (12), Sevenspotted Lady Beetle (7), Asian lady beetle (19), Twicestabbed lady beetle (2 red spots on a black background), Twospotted lady beetle (2 black spots on a red background), Thirteenspotted lady beetle (13), and Fifteenspotted lady beetle (15)

Why do lady beetles have spots? The spots are part of what is called "warning coloration." Insects with bright colors are intentionally announcing their presence to the rest of the world, especially to the bug-eating world. Announcing your location to a predator is an invitation to be eaten, UNLESS you possess a secret defensive weapon (for example, brightly colored wasps and bees that sting).

Ladybugs defend themselves with a foul smelling (and presumably foul tasting) liquid that oozes from the joints when the insect is harassed. Birds, spiders and other predators that tangle with one ladybug learn the hard way that ladybugs are not defenseless. The bright spotted coloration helps the predators learn to not do that again.


ml: isugarden

Extension programs are available to all without regard to race, color, national origin, religion, sex, age, or disability.

News Menu | ISU Extension