With Fewer Pesticides, Black Widow Spiders Find A Feast In Grapes

WASHINGTON - It's hard to know who was more frightened: the 17-year-old Rockville, Md., resident eating unwashed grapes out of a bag, the mother who heard her scream, or their unwanted visitor.

Sheila Laws of Rockville said she bought some seedless red grapes at the Safeway recently, dumped them into a bag and thrust them in the refrigerator, unwashed. Her daughter, Katina Carwile, took them out and was munching on them for a few minutes before she discovered a black widow spider in the bag. Naturally, she reacted.

"I went digging through the bag and I found it," Laws said. "It was very, very, very black."

Black widows have begun to turn up occasionally in grape supplies as growers cut back on pesticides, which has meant more insects for the spiders to feast upon. A grape-industry spokeswoman said growers are trying to deal with the problem.

Laws used salad tongs to put the spider in an empty mayonnaise jar and noticed the red hourglass shape on its abdomen. She took the specimen to the Brookside Nature Center in Rockville, which confirmed her suspicion that it was a black widow, one of the most poisonous - though rarely fatal - spiders found in North America.

Other reports of black widows on grapes have surfaced in the past several years. Spider discoveries were reported by newspapers in Minneapolis last month and in Montreal this summer, for example. The British press has mentioned black-widow sightings as well.

The grape industry has been under pressure in the past decade to reduce its use of pesticides, said Melissa Hansen, research director for the California Table Grape Commission. Consequently, vineyards in California, Mexico and Chile all rely heavily on other bugs to help out.

"You live with a higher insect population with the hope that the good bugs will take care of the bad bugs," Hansen said. "We want spiders in our vineyards and our orchards to eat insects."

Black widows are not among the dozens of harmless spider species used to combat pesky, fruit-destroying insects, though - they just show up to feast on the leftovers. Research has shown that for every few thousand spiders in a vineyard there are about five black widows, Hansen said. Although they are generally found at the base of a vine's trunk or in woodpiles, she said, occasionally a black widow will crawl into a bunch of grapes.

John Deckard, a spokesman for Safeway, said the company is taking Laws' word for it that the spider came from the grapes she bought at its store and not from her house. He said chances are the spider arrived at the store in a crate of California grapes, but he has called in the store's pest-control firm to make sure it did not crawl onto the grapes from elsewhere in the store. The store also has posted a notice informing produce employees of the discovery.

"We have put a lot of money into black-widow-spider research to see what we can do," Hansen said. "What (consumers) need to understand is this industry has responded to the demand to reduce pesticide use; now there's a trade-off for that. . . . We don't have a sterile environment, we have a living vineyard out there. Spiders are beneficial."

Hansen said growers are trained to recognize the especially sticky black-widow web, and carefully inspect the clipped bunches before they are packed and sent to cold storage and on to supermarkets.

"We always stress when you buy any grapes you should rinse them off before you eat them to remove dust," Hansen said.