Pesticides Help Spiders Thrive, Researcher Says

Lawrence, Kansas — It's a common pest, with an average of 65 inhabiting a typical home in this area.
 
But the first reaction of most homeowners who want to get rid of brown recluse spiders — spraying pesticides —  may actually make the problem worse.

While pesticides kill other organisms, they typically don't harm the brown spiders. In fact, new Kansas University research shows pesticide applications may actually help the spiders thrive.

That's because the spider is a scavenger.

"If they are eating the dead things, it's pretty obvious what needs to be done," said Jamel Sandidge, a KU doctoral student in ecology and evolutionary biology. His new research indicates the spiders prefer dead prey over live.

Sandidge studies the spider not only in labs but in private homes. During the past few years he has tracked a variety of the spider's activities in about 400 homes in Kansas, many of them in Lawrence.

Sandidge's most recent study showed the brown recluse fed on the carcasses of dead insects. Many homeowners use pesticides but don't clean up insect carcasses, creating an open meal for the brown recluse, Sandidge found. His study appeared in the Nov. 6 edition of Nature magazine.

"You've got to get out the vacuum or the broom and sweep them up," Sandidge said. "Most people just leave them on the floor."

Source: Lawrence Journal World