Columns

Wild Neighbors:The Curse of Drosophila

By Joe Eaton
Tuesday October 25, 2011 - 10:51:00 AM
Drosophila melanogaster, lab hero and kitchen pest.
Thomas Wydra (Wikimedia Commons)
Drosophila melanogaster, lab hero and kitchen pest.

I’m almost embarrassed to admit this, but I have a fruit fly problem. It’s recent—within the last month or so—and specific to the kitchen. This is a novel experience. We have Argentine ant invasions now and then, and a resident spider population, but never before fruit flies. So far they have me, as my father would say, buffaloed. 

I assume they’re the classic Drosophila melanogaster of genetic fame. I haven’t examined them that closely, though. They’re very small. They pay a lot of attention to fruit, ripe (to the human eye) or not, as well as anything else edible that’s left out on the counter, including such unfruitlike objects as a plate of brownies. 

We’ve gone through several stages of dealing with them, including denial. It didn’t take long before my inner Samuel L. Jackson emerged. Ron found a flyswatter (“The bug stops here,” it says) and that was gratifying for a while. Swatting didn’t make much of a dent in their numbers. Nor did sucking them into the vacuum cleaner, which was an awkward thing to have in the kitchen anyway. 

Ron set up a bunch of traps, with small quantities of vinegar in lab beakers and flasks we’d acquired from a retired chemist. Although the flies seemed interested, there were always more of them. We bought a fruit fly trap at Pastime, our hardware store of last resort: a colorful fruit-shaped plastic container that had to be filled with a special bait that smelled for all the world like vinegar. It seemed to work for a day or two; now they’re ignoring it. 

Preventive measures have been taken. Suspecting they might be breeding in the coffee grounds we saved for use in the garden, we dumped the grounds. We still have flies. I check all the unrefrigerated fruit daily, sequestering anything that’s beginning to ripen. We still have flies. The spiders have been useless; that’s gratitude for you. 

A web site apparently run by the state of California recommends luring the flies into no-exit containers with a piece of banana sprinkled with yeast. We’re willing in principle to try that as soon as we can get hold of a banana. The produce shelves at the soon-to-be-closed University Avenue Andronico’s had been stripped clean as of yesterday. Yes, they had no bananas. 

The fruit fly war has left me in no mood to appreciate D. melanogaster as an organism. Yes, I know that its oversized chromosomes, prolific reproduction, and adaptability to life in the lab have made it the model organism for modern genetics. I know about Morgan and the white-eyed mutant that started it all. I’ve read the books. I still don’t want them in my kitchen. 

What I do have to admire is the creativity that’s gone into the naming of fruit fly genetic mutations over the years. Fly geneticists have been having too much fun. For a sample, check out the fly page at the Curiosities of Biological Nomenclature web site (www.curioustaxonomy.net). Several are named for British baked goods, e.g. clootie dumpling and currant bun. The Methuselah and Indy (for “I’m not dead yet”) mutations prolong life. Lush mediates responses to alcohol. Cleopatra is lethal if asp is also present. Snafu mutants hatch out looking like normal flies but become progressively more abnormal as they develop. Others: armadillo, dachshund, dreadlocks, 18 wheeler, Genghis Khan, glass bottom boat, lame duck, okra, saxophone, shuttle craft, tango, and zipper

I’m also aware that the fruit fly radiation of the Hawai’ian Islands is one of the evolutionary wonders of the world. The founding flies that reached that remote archipelago have given rise to at least 500 species in eight lineages. Some 85 per cent of those are confined to a single island. The males in one group have evolved patterned wings and elaborate courtship displays. Another cluster of species have become parasites of spider eggs. Some Hawaiian Drosophilas are endangered. I wish them well. They’re in Hawai’i. They’re not in my kitchen. 

Maybe I’m approaching this wrong, though. Maybe what I should do is make my peace with the flies, find the microscope that’s somewhere in the storage unit, and watch the damn things mutate.