From Pet to Pest

The Multi Colored Asian Lady Beetle is bugging lots of people where they live.

Our attitude toward our fellow animals tends to be fickle. We may think they’re cute,  as long as we feel secure in our status as alpha predators, lording it over the rest of the food-chain. But when other creatures threaten our comfort-zone in any way, the Disney moment comes to an abrupt halt.

A current case in point: the ladybug. How cute! What could go wrong?

All over Los Angeles, multiple garden plants attract these beloved red-and-black beetles as summer approaches. In my neighborhood, they are madly pupating on the leaves of Buddleia, or Butterfly Bush. For centuries, they have been beloved as a biological control agent, meaning that they eat pests which damage crops, notably aphids and scale insects.

In fact, the “lady” in ladybug references none other than Notre Dame, the Blessed Virgin Mother, Mary.  A medieval legend tells us that, in the midst of an aphid plague, the village prayed and a cloud of Coccinella Septempuntata (7-spotted ladybug) appeared, munched the aphids, and saved the crops.  The red shell of the beetle was seen as a sure sign of the insect’s divine origins, since the Virgin often was depicted in those days wearing scarlet robes. The seven spots on the beetle’s shell represented the Virgin’s Seven Sorrows.

This insect– not a true bug, at all, by the way, and sometimes called “ladybird”, which is even more confusing– has enjoyed cult-status ever since. For instance, ladybugs are championed as our adorable partners in non-toxic gardening, and you can purchase them, live, in containers of 1,500, from garden supply centers and online.

The trouble is, many of the glossy spotted beetles in our gardens these days are not the familiar ladybug of times past, but a troublesome cousin, the Harmonia Axyridis. Native to broad swathes of Asia, this related species has been introduced, both intentionally and accidentally, multiple times in the USA since the early part of the 20th century.

Harmonia Axyridis, also known as the Multi-Colored Asian Lady Beetle, tends more toward the pumpkin-orange or schoolbus yellow range, and has more spots. This insect does indeed chew through aphids better than the best of them, making it a valuable biocontrol agent for pecans and soy crops especially.

But, in doing so, it’s aggressively displacing the 7-spotters. And its voracious appetite extends to eating other ladybugs. It’s also fond of eating the eggs of another of America’s favorite insects, the Monarch Butterfly.

We’ve heard this kind of thing before, all part of the giant, “Thanks for telling me NOW” cautionary tale against the dangers of introduced species. But there’s more.

The Multi Colored Asian Lady Beetle, back in the old country, is accustomed to hibernating in millions-strong swarms in crevices within natural cliff-faces. When it gets cold, they get together and crash until spring.  Similarly, in the forests of North America, hungry bears seek out fallen tree-trunks which may contain a nourishing cache of drowsy ladybugs, and gobble them down by the crimson pawful.

But across the USA, the introduced variety has become fond of human habitations instead. When the snow flies on the lonesome plains of Iowa-y, they get comfy-cozy for several months in a protected indoor space (between beams, or in the attic or basement), usually without the consent of the mortgagees. Then when the air-temperature reaches about 50 degrees Farenheit, it’s wakey-wakey. They pour out of kitchen cabinets like a shiny rain of m&ms, spilling down walls and slithering in gleaming waves across floors, triggered into action by a combination of sunlight, pheromones and the urge to make ladybug-whoopee.

As with so many things, proximity–and quantity–breeds contempt. People who find themselves cohabiting with the Multi Colored Asian Lady Beetle have revoked the insect’s blessed, “good luck” status. One reason: when jostled, the beetle employs “reflex bleeding”, exuding a stinky, bitter, yellow alkaloid toxin from the joints of its legs. The point of doing this is to discourage you from swallowing it. This may seem like a given, except that they often land in martinis and cups of tea during a full-on infestation.

The liquid the insect exudes may stain light-colored surfaces, and some people report allergic responses to it, including eye-irritation.

Some people claim they have been nipped by the beetles, although these insects do not have any capacity to sting or pierce the skin in any way.

Like most insects, once they lay claim to your space, they are reluctant to leave. Black-light traps and vacuuming are among the current treatment techniques.

The professionals say that prevention (i.e., sealing up every crack on your property) is, of course, the best way to deal with potential infestation. So, the next time a ladybug lands on your morning paper (a-w-w-w-w…), just open the screen-door and tell it to fly away, fly away, fly away home– and leave yours alone.

–Victoria Thomas

Victoria Thomas

About Victoria Thomas

Brooklyn-born Victoria Thomas loves writing about flora and fauna, although she chooses to do so in an urban setting. If she had it all to do over again, she might have become a forensic entomologist. She lives in Los Angeles.
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