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They're Not So Innocent

Although useful in the garden, this bug isn't always a lady

Irene Virag | GARDENING

September 14, 2003

The seven-spotted ladybug beetle, pictured, which decimated New Yorks native nine-spotted ladybug beetle population in the 40s, later came under attack from the Asian ladybug beetle. (Newsday Photo/Bill Davis)

Hornets give me the heebie-jeebies, mosquitoes make me itch and I shudder at the sight of carpenter ants. I do not court the company of spiders. Roaches revolt me and I reach for a swatter at the buzz of a fly.

But until recently, I had always thought of ladybugs as insects of a different color - and I just don't mean red with black dots. Ladybugs are cute. Ladybugs are a gardener's best friend. They eat aphids. And there's the old rhyme that starts "Ladybug, ladybug, fly away home ..."

Last fall, a ladybug showed up in my home. If it were any other beetle, I probably would have squashed it like - well, a bug. But it was a ladybug. "Make yourself comfortable," I said. Folklore has it that a ladybug in the house portends all sorts of good luck - romance, children, pots of gold. I already have romance and three stepchildren almost as old as I am. I was holding out for the pots of gold.

The ladybug stayed around till spring, popping up here and there and now and again in different parts of the house. But the gold never came. And now I find that I shouldn't have been so hospitable. My guest wasn't exactly what I thought. Yes, it was a ladybug or lady beetle as they're more often called these days, but experts tell me that it most likely was the invasive multicolored Asian lady beetle.

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Instead of hibernating beneath logs and leaves like self-respecting native ladybugs - the convergent ladybug, for instance, or the pink spotted ladybug - the multicolored Asian lady beetle goes indoors in October. That - plus its occasional pumpkin coloring - is why it's sometimes called the Halloween lady beetle. I'm lucky I wasn't deluged by hundreds of its relatives.

So forget all the PR. Ladybugs have a dark side.

First, a little background. About one-fourth of all the animal species on our planet are beetles, and more than 4,000 of them are ladybugs. Their family name is Coccinellidae, which means "clad in scarlet" - and about 400 different types live in North America. And they're not all clad in scarlet - they come in orange, black, yellow and pink.

Basically, the bodies of ladybugs are hardened wing covers made of chitin, the stuff of human fingernails. Beneath these colorful covers lie transparent wings strong enough for a ladybug to flap 85 times a second. Ladybugs have six legs and two antennae that are used to touch, smell and hear. They also can smell with their feet. Think about that the next time you let a ladybug walk all over you.

The main reason for their goodie-goodie reputation is that aphids - the archenemy of roses - are their favorite food. A female ladybug can eat about 75 aphids a day, and she'll go on a feeding frenzy and pig out on about 300 a day of the pear-shaped sap-suckers before mating and laying eggs. Sometimes she mates and eats at the same time. How gross is that?

Mother ladybugs deposit clusters of as many as 50 tiny yellow eggs on the undersides of leaves near aphid colonies. That way ladybug larvae - which look like tiny, blue-black alligators with orange spots - won't go hungry. By the way, the female keeps laying eggs over a three-month period, and as many as six generations could hatch in a year and gobble up 200,000 aphids.

Ladybugs know a thing or two about protecting themselves from hungry stalkers. They roll over and play dead. Or if they're stressed, they exude a foul-smelling yellow-orange fluid from the joints of their legs that makes them distasteful to birds and spiders.

So forget cute. And consider the history of ladybugs in our fair land. Almost half the ladybugs found in North America were introduced as biological controls of aphids and other soft-bodied pests like scales. But one good turn hasn't always resulted in another.

It all started in the winter of 1888, when a tiny ladybug called the vedalia beetle was imported from Australia to save the California citrus crop from a scale. Its success triggered a wave of ladybug imports. But the exotic pest-controls spread. For instance, the seven-spotted ladybug, brought from Europe in the 1940s, decimated our native nine-spotted ladybug. Not that the nine-spotted species is forgotten. Decades later, in 1989, it was named New York's official insect by the state legislature. "Someone came up with the nine-spotted ladybug because records showed it was a native," said entomologist Tim McCabe, curator of the insect collection at the New York State Museum in Albany. "They didn't realize the seven-spotted ladybug had wiped it out across the state."

Now the multicolored Asian lady beetle is bullying the seven-spotted ladybug. Harmonia axyridis - which has a black M on its head and comes in various combinations of spots and colors - debuted as a biological control agent in 1916 in California and was introduced in other states over the years. It's fast becoming the dominant ladybug of the land.

"When something like the Halloween bug shows up, it disrupts everything," McCabe said. "I don't think the native populations of ladybugs will ever recover from it. It's not cute."

"It's big and voracious and reproduces quickly," says Jody Gangloff-Kaufmann, an entomologist and Long Island specialist with Cornell University's integrated pest management program.

The problem with the Halloween bugs is what they do when the cold comes. In their Asian homelands, they winter in cliff crevices. Here, they congregate on the south-facing sides of buildings and snuggle indoors. This could mean your house or Suffolk County's Dennison Building in Hauppauge. On sunny days or when the heat's jacked up, they bop around or gather on windows by the thousands. Which accounts for my lone visitor and the hordes that show up in Suffolk's seat of government, where light traps are placed in the ceilings to attract them so they can be relocated.

They don't feed or reproduce while indoors. They don't eat wood or otherwise damage structures. They don't carry diseases. But their swarming ways are a nuisance and their smelly orange ooze can stain almost any surface. I didn't see any stains on my rugs or curtains over the winter, but, come to think of it, I did have some mysterious nips on my legs - multicolored Asian lady beetles don't actually bite but they've been known to pinch.

Like I said, nothing's what it seems to be. Even ladybugs. Their appetite for aphids keeps them in the good bug category, but if I find one inside this fall, I'll vacuum it up, as the entomologists recommend. Or I'll toss it out the door.

Ladybug, ladybug fly away - from my house.