The brown recluse spider is a common spider in the southeastern United States, but its territory has increased over the past several years to include midwestern areas, such as Champaign-Urbana.

The spider has been found in three schools in Paxton, Ill., most recently at Paxton-Buckley-Loda High School.

Brown recluse poison is said to be deadly, causing necrosis, or the death of human cells and tissue, to those particularly sensitive to it. However, the spider rarely bites, and there are not many studies or cases on brown recluse spider venom, said Phil Nixon, an extension entomologist in the department of Natural Resources and Environmental Sciences. Often, all the venom will do is cause a rash.

“How a person reacts to a poison depends on the genetic makeup,” Nixon said. “This is not a spider which commonly bites.”

Brown recluse spiders commonly come out to hunt for food at night and avoid daytime. They migrated to midwestern areas most likely by traveling in people’s possessions. It is much more common to find them in buildings and farmhouses below Interstate 70, which Nixon said seems to be a man-made border to the places where they can live year-round.

“It just seems to be the nicest limit to surviving outside,” Nixon said.

But in the South, Nixon said the spiders are as common as dogs. Also, their bites are often over-reported, giving them a much more fearsome reputation than they may deserve. This is because anyone can report a spider bite to the Centers for Disease Control and Prevention in Atlanta but few can successfully claim that the brown recluse is at fault for the bite because it is not captured at the time.

“I can decide to report a bite when nothing has happened to me,” Nixon said. “It’s an easy thing to do.”

W.K. Floyd, owner of M&S; Pest Control, 2501 Sheridan Drive, Champaign, said that though he has not seen the spider this year, he has seen them and confirmed their existence in Champaign-Urbana homes. Floyd was born in Alabama and nearly lost his grandmother to a brown recluse spider bite. He said it is always important to be cautious when near the spider.

“I wouldn’t want to get bit by one,” Floyd said. “I think it’s a big deal.”

The spider varies in size from six to 20 millimeters long and may have markings along the body that look similar to violin strings. If a spider is found, it should be captured for proper identification before being killed, Nixon said. Also, if a bite occurs and the victim begins to breathe heavily, he should seek immediate medical attention. The spider may be increasingly common in the Midwest, but the effect of its bite is still uncertain.