Ladybug, Ladybug, Fly Away Home

It was two days before Halloween, and there was the seasonal spirit of ghouls and witches impatient to descend. I was busy carving pumpkins in the late afternoon sun when I looked up to an even more nightmarish vision: the full side of my house darkened and writhing. With a closer look I realized I was witness to thousands upon thousands of ladybugs swarmed all together on the usually bright white clapboard siding, and more were coming, in my hair, up my nose. I shrieked, feeling like a Hitchcock blonde under attack, and rushed to open the back door to get inside. The ladybugs had the same idea. Great clouds of the creatures swarmed into the house, taking up positions by the hundreds and thousands in the corners of every room, in each recessed lighting socket, in the hems of my curtains - literally every nook and cranny of the house.

We grow up loving ladybugs as children, and as adults we are taught that they are our garden saviours, devourers of the aphids that prey on our roses. Their common name is testament to their popular esteem; since they were so beneficial to the farmer in aphid control they were taken to be a blessing sent from the Virgin Mary, and given the moniker ’Our Lady’s Beetles.’ If a single ladybug is spotted on a rose, or on my clothes, I will take great delight in letting it clamber over my fingertip and protect it until it flies away like the nursery rhyme. En masse, my reaction was the opposite; I got out the vacuum cleaner.

To assuage my guilt at the ensuing mass ladybug genocide I did some research. These are not the native nine-spot ladybug Coccinella novemnotata, they are an imported non-native species from Asia called Harmonia Axyridis. The native ladybugs like to over-winter under bark and fallen leaves, but the nonnatives like things a bit more plush, and prefer the walls of our houses. However they are useful. They were imported as pest control and do a valiant job. I found one report that told of its great success at controlling another non-native soybean aphid, saving the soy industry a great deal of money, and they are also beneficial in the garden for this purpose. It is postulated that they swarm in areas with high aphid populations, and so their numbers ebb and flow with the pest they feed on.

But they do also have a darker side. They outcompete native ladybugs for food sources, are highly resistant to diseases that kill the natives, and as such spread them as well as a parasite that kills the natives off too. There are increasing reports of their contamination of fruit crops with some evidence to suggest that their presence on grapes on the vine alters the taste of the future wine. Indoors they release an odor when frightened, and I also read that if you leave them be to happily over-winter they will release a pheromone so that future generations will keep returning to that place for years to come. There are reports that they can bite humans, and I was certainly fascinated to watch them fall and play dead when I approached with my vacuum cleaner, only to revive themselves and scuttle off when they thought the coast clear. They are certainly clever, worthy of admiration, and it is hard to get angry with a creature that is clearly only trying to survive and to find a cozy warm spot over the winter, but when they are ten deep and coating window frames and door frames by the square foot one’s hospitality goes out the door far quicker than the bugs. I have since vowed that if my home is host to another swarm this year, I will still vacuum them up as before, but this time I will take the vacuum cleaner up to Bear Mountain and release them and let them become someone else’s problem, with the hope that they find a nice cave instead of someone else’s house and continue to do their good work in pest control the following summer.

If you are interested in documenting native or non-native ladybugs seen in our area and how to identify them, as well as great kids activities, go to