Summer’s Last Stand

Getting to know my uninvited guests

by Vicki Marsh

Do you really know who — or what — you’re bringing into your home?

Apples have replaced summer’s peaches, but my guests are still with me.

One afternoon, in September, I brought home sweet, juicy yellow peaches, fresh from a farm stand. I dropped them into a glass bowl and sniffed their sweet aroma. I could hardly wait for breakfast: fresh peaches for my cereal in the morning.

What I didn’t know was that invisible invaders were lurking nearby, waiting to sample my peaches.

In the morning, tiny flying insects hovered around my fruit bowl.

I shooed them away; I peeled a couple of peaches for my cereal. This set off an alarm. Out of nowhere hundreds of fruit flies, or so it seemed, were vying for my bowl of cereal.

They’re still around, apparently just as happy with apples and bananas as with peaches.

Where do these pesky little flying critters come from? These weren’t there when I bought the peaches, but arrived, unseen and uninvited. How do they appear out of nowhere?

There’s more to them than meets the eye.

Invaders Found Out

Fruit flies, as it turns out, have a life, a wild outdoors life.

Drosophila melanogaster is the most common species of fruit fly, but there are hundreds of others, each one with its own markings, wing pattern and color. But these eighth-inch long, red-eyed insects all have one thing in common: Their whole sensory apparatus is devoted to sniffing out the distinctive odors of fermentation.

They are attracted to rotting and fermenting material, according to Sue DuPont, spokeswoman for the Maryland Department of Agriculture. “They come when they smell your peaches nearing — what they consider — the rotting stage.

“Flies are not interested in unripe material; they only like rotting material,” DuPont says. “If you find flies immediately on your fruit, then it has begun to rot, and the flies have already visited the fruit and laid their eggs underneath the skin. But not to worry. Ingesting them won’t harm you.”

That explained why I didn’t see any flying critters around the fruit stand. Everything was fresh.

You can use your new-found knowledge of their taste for rotting fruit to get rid of the insects. Before your uninvited guests use your fresh produce for a nursery, find a secure covered area. I hide my fruit in the refrigerator, a covered bowl or the microwave — though hidden fruit has its own disadvantages.

Another solution is more generous. I share my wine, which is the result of fermentation. A wine bottle — or any bottle with a narrow neck — will work. Leave a little wine in the bottom to entice them in; then roll a piece of paper into a funnel and insert the narrow end into the bottle. A few sips of the ole’ vino, and they’re trapped.

You’ll be killing a near relation.

James Erickson, a biology professor, at Texas A&M University has identified many similarities in human and fruit fly genomes. A genome is part of our chromosome and part of our DNA.

I was amazed to learn, however, that this tiny nuisance could be valuable in helping us fight diseases.

“Those small fruit flies buzzing around your bananas are more than pests,” Erickson says. They may be allies in a fruitful search for clues to human diseases caused when genes malfunction.

Says another scientist: “The little people with wings are pointing the way to advances in curing birth defects, cancer, degenerative diseases like Huntington’s and aging.”

Each female can lay 500 eggs in her short eight-day life span. Their rapid reproduction gives scientists a plentiful supply of fast-evolving subjects.

Research on fruit flies may help scientists understand, for example, how the sex of mosquitoes is determined, with an eye to eradicating those that carry diseases, Erickson explains.

It’s getting on to Christmas and I’m still bothered by a few fruit flies in my kitchen. I’m praying that the frosty season — and my holiday wine — will end their invasion.

Until next year.

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