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NUTS AND BOLTS : Cannibal Snails Eat at Their Own Pace

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Is there room in the human psyche for a passion for both horror movies and gardening?

A real stumper, isn’t it? Imagine sending your average Joe Six-Pack to a slasher film festival, then handing him a Garden Weasel and pointing him toward the rose bushes. Result: lots of yelling, and American Beauty mulch.

Gardeners of my acquaintance are serene folk, lovers of subtlety and delicacy, custodians of beauty, enhancers of life, keepers of the earth.

Horror movie fans (particularly the ones who adore the slasher sub-cate-

gory) like to go fishing with bazookas, cut their blood-rare steaks with chain saws and think they’ve been cheated out of the price of their Indy ticket if at least one of the Andrettis doesn’t go up in flames.

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These people would take up gardening only if it were legal to use spitting cobras for aphid control.

But wait. The gardening world may yet be joined by the Freddy Krueger Fan Club once word gets out about . . .

The Killer Snails!

Yes! Hideous cannibalistic terror right there among your aspidistras! Horrible, ghoulish, flesh-feeding monsters! Rapacious, ghastly slaughter in your very own flower bed!

If you loved “Nightmare on Elm Street VII (to the 10th power),” that sounds pretty good, right? Especially when you realize that the favorite snack of these little hellions is their cousin, the common brown garden snail. Call it cannibalism if you like, but there’s a subtle wrinkle here: The killer snail--or Rumina decillata-- is smaller than the brown, or helix, snail, and has a conical shell. They look like sea snails. And they also chow down on dead leaves and molding fruits and vegetables.

Otherwise, though, they’re the invertebrate world’s answer to the Visigoths.

Ray Harrie thinks they’re wonderful. He sells them. His company, Bio-Con Systems in San Bernardino, has been providing killer snails (Harrie’s pet name for Rumina ) to Southern California gardeners for about 10 years now. To the organic gardener, he says, they’re as good as hiring a bunch of gunmen led by Yul Brynner.

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“It has odd behaviors that we find useful for biological pest control,” said Harrie, who is a pest detector (“one of the guys who chases Medflies”) for the San Bernardino County Department of Agriculture.

Odd? Make that horrific, at least in brown snail terms. The scenario is straight out of “Night of the Living Dead.”

You take a snail and place it under a small plant (multiple snails are used for larger plants) and wait a bit. The snail will burrow into the ground and stay there throughout its lifetime. It’s unlikely, said Harrie, that you’ll ever see it again. But it’s in there. And it’s hungry. And mean.

“It’s not a moving animal,” Harrie said. “It’s territorial. It stays put under the bush and defends that territory.”

Enter the unsuspecting brown snail, intent on finding damp, cool soil in which to build a burrow and lay eggs. This is exactly where the killer snail has made its home. Never mind that the brown snail can move at the blistering clip of 75 feet an hour and leave Rumina in the dust (“We’ve caught (the killer snails) going as fast as 60 feet a year,” Harrie said). The brown snail isn’t going anywhere. It’s laying eggs. And the killer snail begins to stir. . . . The weird music starts. Someone screams, “Don’t go into the basement!”

But it’s too late. The slimy little Dracula has struck.

And it doesn’t stop there. When it’s done polishing off the snail, it eats the eggs too.

And it will keep repeating this ghastly tableau for two years. Then it dies. But before that happens, it lays eggs and new generations of killers take over the territory.

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The butchery eventually ends nine months to a year after the killers were first introduced to the garden.

The killer snails have been carrying on this sort of slaughter in America for about 100 years, said Harrie. They came originally from the southern coast of the Mediterranean Sea and are considered a desert snail. They began to show up in the the Carolinas about a century ago and brown snails in the area soon started to disappear. But at the time, said Harrie, “nobody put two and two together.”

Then, in the mid-1960s, they showed up near Riverside.

“We’d been searching the world over for just such a control,” said Harrie, “and the thing comes right to our door.”

Commercial snail poisons are always available but, said Harrie, they have become more dangerous as the brown snail has developed more resistance to the central nerve poison they contain. Over the years, the concentration of the poison has had to be increased “to the point of being deadly to vertebrates”--this means pets and small children--if it is ingested.

Citrus farmers were the first to take to the killer snails eagerly, and Caltrans has been using them alongside freeways since 1977, said Harrie. He sells them packed in a bit of soil in lots of three dozen (about $9.50), 100 (about $21) and 500 (about $90). They can be ordered by writing to Bio-Con Systems at P.O. Box 30186, San Bernardino, Calif. 92413, or by calling at (619) 242-3800.

And if the munching noises keep you awake some gloomy night, relax. Put a slasher movie on the VCR and have a little escargot.

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