The charming, useful ladybug
During the warm months of the year, ladybugs are like adorable, bright-colored lapel pins. They land on us, accessorize our clothing in brilliant red or orange with stylish black spots, and are delightful to have around. Several cultures even think of ladybugs as good luck charms for anything from marriage to childbirth to the weather to a good harvest.
Then fall arrives and the ladybugs need to find warmth, which is most available inside people’s homes — where they often descend in large numbers. Suddenly they’re not as cute to many people as they seemed outdoors. But Jessica Ware, an insect expert and assistant professor of biology at Rutgers University-Newark, says having ladybugs indoors serves a very useful purpose, and humans should welcome their temporary houseguests.
“They’re actually great to have around,” Ware says, “because they’re most often predatory and they eat the insects we consider to be pests — especially aphids, soft-bodied insects that feed on vegetation. If you have aphids on any of your houseplants, and you have ladybugs in your house, you’ll no longer have aphids and your plants will be fine. Do not kill them. Do not spray them — because if you do, then you’re destroying some of the natural predators that keep pests in check.”
Because ladybird beetles (which Ware points out is the insects’ actual name) gather in big groups — mutually attracted by each other’s pheromones — they’ll often enter just one home in a neighborhood and skip the others. Ware says there is no good way of predicting which house they will want — except that they tend to like their environment moist and warm — much as we humans do.
If they’re already in your house, says Ware, you’ve probably got them ’til spring. Many will die over the winter, and those that don’t will go back outside when the weather warms up. That is when Ware says you will have performed a true public service by hosting them through the cold months. They’ll devour aphids in your garden — if you have one — as they did all winter for your houseplants. They also will go after aphids in your neighbors’ gardens — as well as on farms where summer fruits and vegetables grow.
“Aphids are one of the most common pests in people’s flower gardens and they especially like to destroy ornamental plants like tulips and daffodils and the beautiful things you see in spring,” says Ware. “Aphids basically suck the juice out of the plants and kill them, and they can breed by the thousands in a matter of days. But not if ladybirds get them first.”
Ware even wishes that ladybird beetles had come to her mom’s house one year when they didn’t. “My mother had a beautiful jade plant that her mother had had for decades, and she got scale insects on it. In a short matter of months, that plant was destroyed. Having ladybugs would have solved that.”
People may wonder why ladybird beetles are so brightly colored — in reds and oranges and even yellows. Ware says the colors protect them from birds and other predators that otherwise would want to eat them.
“Birds that have tried to eat monarch butterflies, for example, don’t forget how foul tasting and vomit-inducing the monarchs are, and learn to avoid them. Many predators learn to avoid anything with bright so-called “warning” coloration — including the ladybird beetle, which has this kind of coloration and also is foul tasting.”
But if birds shy away, humans still find them beautiful — as least when the ladybirds are not indoors. Ware says that — of course — there are both male and female ladybirds, but they probably have “lady” in their names for the same reason another species of insect is called the damselfly. “If insects are attractive or delicate, they’re called female, and ladybirds are.”
The above story is based on materials provided by Rutgers University. The original article was written by Rob Forman.