Migration

“Ladybug, ladybug fly away home…” Whoops, she did! And she’s made my home, and perhaps your home, her home. With spring just around the corner, she’s awakening and coming indoors.

Ladybugs are such lovable creatures that we — or I, at least — can’t call them a pest even when they act like one. Just now they’re creeping on windows along with cluster flies, also benign creatures but “pests” not at all welcome in my home. Ladybugs do get even peskier indoors: I occasionally find them marching across a pillow just before I lay down my head or scuffling along the edge of a teacup just before I take a sip.

It’s not your imagination that the annual ladybug migration indoors has increased from years’ past. These homebodies are one particular kind of ladybug, known officially as Harmonia   axyridis or, commonly, as Harlequin beetle or Asian multicolored lady beetle. Like other species of lady beetles, Asian multicolored lady beetle is friend to gardener and farmer, and she was deliberately introduced from Asia to help us out here. She’s happy in her new home and thus far has escaped enough natural predators to let her numbers soar and spread.

(Note the word change in the previous paragraph from “ladybug” to “lady beetle.” That comes about because when scientists enter the picture, as in naming Asian multicolored lady beetles, they’re more exacting. Ladybugs are not true bugs, genus Hemiptera, but beetles, genus Coleoptera. Or, to delve deeper etymologically into entomology, lady beetles are in the Family Coccinellidae; that word derived from coccineus, Latin for red. A couple more tidbits: the insects are called “ladybirds” in the UK, Marienkafer, meaning “Mary beetle” or “Mary bug” in German. The “lady” in all these common names refer to the Virgin Mary who, in older paintings, is often wearing red, as do lady beetles, usually.)

Harlequin beetles are not easily distinguished from the almost 6,000 other ladybug species worldwide.

Harlequin beetles

With a red, orange, or yellow-orange back dotted with anywhere from none to twenty dark spots, she looks like . . . well . . . a ladybug. Recognize her mostly as the ladybug that comes to your breakfast table. Or, more scientifically, by the W on her head.

Pests or Pets?

This season’s encounters with lady beetles began last fall. Harlequin beetles are also known as Halloween beetles for their habit of clustering on walls in late October, preferably light colored walls that face southwest and are not too far from wooded areas. Later in the season, frosty weather drove them to seek shelter in cracks and small openings in the wall. They’re hoping to find shelter that is cool, to limit burning up their energy supplies, but not too, too cold. 

With spring just around the corner, the beetles are awakening. Perhaps bleary eyed, they don’t remember how they got into a wall, so as they creep around looking for light, some find their way into our homes. 

These bugs could be looked upon as cute pets. And they wake up hungry, so will devour some aphids and scale insects.

Lady beetle larva

Lady beetle, eggs hatching

If they don’t soon find sufficient food, they die.

Lady beetles don’t want to be indoors and neither do we really want them here — at least not so many. One way, then, to please ladybugs and humans is to check and repair caulking around window and door frames or any other potential entry points. Any gap larger than 1/8 inch provides an invitation.

They hang out on windows because they’re attracted to light. (So am I, especially in late winter.) So a win, win situation for these two and these six legged creatures alike might be now and then over the next few weeks to open a window for a few minutes; the ladybugs will stretch their wings and be off — maybe. 

Even better is to use a light trap. Not one that zaps and kills them, for a reason I’ll soon get to. But one that just eases them into a container, such as this design from the USDA for a home made trap: https://www.ars.usda.gov/is/br/lbeetle/001030.trap.pdf. With this trap ladybugs fly towards the blacklight, bump into smooth plastic, vertical panels, then slide through a funnel into into a waiting bag which can be periodically emptied outdoors.

Gentle Removal

One thing you definitely do not want to do is to crush, swat, or overly upset any lady beetle. When upset she’ll emit a yellow fluid (hemolymph, their blood) that has a very foul aroma and taste. Not that you’d taste it but it does keep birds from going for the insects. 

Dead ladybugs stink and attract other insects. Carpet beetles, for instance, which, besides carpets and dead lady beetles, also dine on leather, soft wood, grains, and many other things. Not an insect you want to attract.

Gathering lady beetles up with a vacuum cleaner is also a no-no because when the beetles reach the impeller, all hell breaks loose with chopped bugs and hemolymph. Unless, that is, you stretch a nylon stocking over the intake hose, emptying it outdoors when sufficiently full.

Not to close on a sour — or stinky — note, let’s remember that these beetles control aphids, scale insects, mites, whiteflies, mealybugs, and other plant pests. Specific kinds of ladybugs have their preferences. In past years, scale insects ran amok in my greenhouse. I ordered some larvae (they stay around better than mail-order adults) of Cryptolaemus montouzieri, commonly known as the “mealybug destroyer” and they took care of the problem. Unfortunately, they did not establish there to help out the next year.

Even as I release ladybugs outdoors in coming weeks, I’m hoping that they don’t fly too far away. To that end, I’ll plant dill, daisies, and other flowers heavy in nectar in my garden as well as limit use of pesticides. But Ms. Ladybug, mi casa no es su casa. Fly away home.