Gardeners Cringe As A Bumper Crop Of Slugs Slithers In
By Teri Randall
Chicago Tribune, 8-8-1998

It’s slime time.
Hordes of slithering slugs, in greater numbers than usual this summer, are staging late-night orgies munching on marigolds, having kinky sex and drowning in stale beer in the most respectable gardens in the Chicago area.

Joining the summer binge are centipedes, earwigs and sow bugs—in short, all those creatures that delight in cool, moist, decaying places and making pests of themselves.

Blame it on the weather. Those same conditions that brought this summer’s mosquito infestation—too dry last year, too moist this year—are bringing out the garden pests in surprising force

"They loved my delphiniums," Teppi Schmidt of Gages Lake in Lake County said of the slugs that have been inching all over her lawn in recent weeks. She didn’t even get the flowers planted, she said.

"I had them sitting out on. the lawn, and they ate them right out of the pot,’ she explained.

Slugs look like snails without shells. Two pairs of antennae extend from the tops of their knobby heads, and those who choose to look at a slug up close and personal will find tiny eyes at the tips of the longer pair of antennae.

Slug gluttony is a problem now in parks and gardens all over northern Illinois, according to Meegan Bilow, supervisor for plant information at the Chicago Botanic Garden. And being an expert hasn’t helped Bilow in her own back yard in Wilmette.

"The slugs have just riddled the leaves on the hostas at home. They look like Swiss cheese," she said.

Hostas, a knee-high, round leafy plant with purple flowers that is extremely common in Chicago area is the most frequent victim of slugs here.

"I haven’t seen a perfect hostas without one or two little feeding marks," Bilow said.

Plant stores throughout city and suburbs are selling of slug bait, a pellet that poisons the inch-long, wriggly pests, gardeners with telltale slime trails on their patios try to protect their plants.

"The slugs are really bad this year," said Robert Shields, manager of the Village Green plant and garden center, which was out of slug bait for a month before a shipment of 50 cases arrived last week. "You can never control the damn things, especially after a mild winter like last year."

Slugs lay eggs from spring to fall, said Fred Miller, entomologist for the University of Illinois Cooperative Extension Service. Though the adults do not survive the winter, the eggs lie dormant until the following spring.

But if the following year is too dry, as was the case last year, slug eggs—like those of mosquitoes and other insects—will wait to hatch the next spring, Miller said This years’ hatch, which began in the spring, was thus much more plentiful than usual.

"The slugs come out at night," Shields said. "They slither up out of the ground where ever soil meets wood or stone. Then they just crawl along the ground until they find a plant."

They eat just about everything that’s soft and leafy. They pass up rhododendrons and evergreens, which they find too hard to eat, but everything else in the garden, including roses, is potential slug food, according to Shields.

They committed a wide range of botanical atrocities in Teppi Schmidt’s garden.

"I had seeded a bunch of annual flowers into the bed, and they devoured those," she said. "They would come up with two or three little leaves, then the slugs would eat them back ‘till there was nothing but a little stalk sticking up, and then they’d die," Schmidt said.

Slug opponents can fight back with chemicals or beer.

Slug bait contains either mesurol or metaldehyde, the slug equivalent of arsenic. Stale beer is the time-honored organic alternative.

(Ed note: metaldehyde is extremely attractive to pets, especially dogs and is very toxic.)

"Sink saucers into the ground, and pour beer in them," Shields suggested. "The slugs slide into the beer and drown. It works."

Slugs, apparently, have discriminating tastes for beer, as discovered in the 1987 official slug-fest at Colorado State University, where researchers ran experiments to determine which beer attracted them the most.

The most attractive beer tested wasn’t a beer at all, but a near beer, a malt beverage with zero alcohol content," Miller said. The experiment showed that products of yeast fermentation, not alcohol, were the attractant.

Kathy Gass, home horticulturalist at the University of Illinois Cooperative Extension Service for south Cook County, has found that the available slug baits work "haphazardly" in her Glenview garden. Physical removal is her most effective strategy.

"I go out at night with a flashlight and pick them off with tweezers," she said.

The slug's slime trail is made of mucus and helps the creature glide over the ground and protect itself from sharp objects in its path. But laying down slime also causes dehydration; hence, slugs prefer to go out on moist, windless nights.

When it comes to reproduction, slugs have many options. Slugs are hermaphrodites, containing both female and male sex organs. After an elaborate courtship, two slugs fertilize one another.

But when necessary, slugs can fertilize themselves.

Though slugs have zero redeeming qualities in the garden, they do serve as food for toads, insects, birds, chickens and ducks, Miller said.

In addition to slugs, earwigs, centipedes and sow bugs are also experiencing a heyday thanks to the moist climate this summer.

Earwigs—long, brown and shiny, with pinchers on their tails—can eat the foliage off a plant leaving only threads where the stems and veins once were, Bilow said.

"Ten years ago, they weren’t considered a plant problem, but now earwigs are so plentiful’, they’re considered a plant pest," said Bilow, whose office fields 12,000 phone calls a year about plant questions.

"Most callers complain about earwigs because they’re coming into the house. People find them in their sinks. I opened my oven one day and an earwig walked out."

Earwigs apparently don’t have a penchant for beer, but chemicals like carbaryl and chlorpyrifos will do them in, Bilow said.

(Ed note: Earwigs are attracted to Snailer and Slug Saloon bait and are caught in the traps. Bran based baits with microbes or boric acid also work against earwigs.)