As the demand for organic products grows so does the use of natural predators like spiders as a kind of biological pest control. The grapes aren’t harmed by the spiders who prey on insects.
“IPM (integrated pest management) is very mainstream in the table-grape industry and has been for a while now,” Kathleen Nave, president of the California Table Grape Commission, says. “It’s just a smart, logical way to grow grapes, and spiders are a beneficial part of that.”
In vineyards spiders account for 95 percent of predators used in IPM. Some of the vines have 10-50 spiders on them. Increasing percentages of black widows are being used. This is posing a serious problem though for the humans who love the grapes.
Not only do black widows thrive in organically farmed grape orchards where insects of all types abound, but they’re also thought to be resistant to many of the newer, less toxic insecticides and pesticides currently used by conventional growers.
Grapes aren’t the only fruit that carries spiders at times. Bananas have been known to have large brown spiders attached to. Last month a store manager at a Tulsa, Oklahoma Whole Foods found one of the spiders. It was feared that the furry beast was the Brazilian wandering spider which is one of the world’s more venomous spiders. It turned out to be a huntsman spider who just looks like a killer.
While most of the spiders are cleared from the fruit during the packing stage some do manage to take a free ride from the vineyard to a grocery story.
In Australia and New Zealand grapes are gassed before they are brought into the country.
“Organic growers don’t have a lot of proven options for controlling spiders,” Dr. Devin Carroll, an IPM consultant who has spent more than 20 years observing spiders in vineyards, says. “Care during packing is important, but it’s hard to avoid missing a few.”