Students living in University Village had some unexpected house guests this summer – brown recluse spiders.

The spiders, known as Loxosceles reclusa, were reported in University Village in July, said Kate Bruns, communications specialist for the Department of Residence. All spider reports came from apartment building 148.

Glue boards were laid on apartment floors to catch the spiders as they emerged from the corners and dark spaces they prefer. Reports of spiders continued throughout the summer, so the department called ABC Pest Control from Des Moines last week to apply a treatment called an “exciter,” a chemical similar to tear gas, Bruns said. The exciter is designed to scare the spiders out onto the glue boards. Residents were asked to leave the building for two hours while the treatment was applied.

Alternate housing arrangements were offered to all residents of the building, but only two have moved out of their apartments. “We’ll come back every couple of days to monitor the situation,” Bruns said.

Brown recluse spiders are probably the most poisonous spiders in the United States, said Wayne Rowley, professor of entomology. However, 90 percent of bites result in “little or no injury.” He said the bites result in small, blister-like lesions on the skin, and develop into an “oozy-type open sore.”

“The poison is actually a neurotoxin and a cytotoxin. The [neurotoxin] damages the nerve endings around the area where the spider bites the skin, and the [cytotoxin] kills the cells,” Rowley said.

The Iowa Poison Control Center Web site, www.iowapoison.org/Spiders.htm, describes the bite as a bruise with a small blister in the center, which may look like a bull’s-eye or a halo. The blister can break and leave an open sore that is painful, itchy and red. It advises applying a cool wet cloth or a bite pack, and notifying a doctor upon the onset of chills, fever, nausea, convulsions or extreme fatigue, or if the bite area is larger than a quarter-inch.

Rowley said the idea that brown recluse spider bites leads to death is “greatly exaggerated,” but recommends anyone who suspects they have a bite see a doctor as soon as possible.

The brown recluse is not an aggressive spider, he said, but instead prefers to hide in dark areas such as garages, basement and unused shoes.

“Most bites occur when the spider is forced against the human skin,” Rowley said. “It’s a defensive move on the part of the spider.”

Brown recluses do not use webs to catch their prey, but instead rely on their quickness.

Brown recluses are relatively uncommon in Iowa, as they are unable to withstand Iowa’s cold winters, he said.