Archive for Saturday, July 22, 2000


Identifying the brown recluse spider

July 22, 2000


Mmm, summertime.

The season signals the arrival of baseball, apple pie and barbecues. Oh, and don't forget brown recluse spiders -- whose venom can be deadly.

Beware the brown recluse!

Beware the brown recluse!

The dangerous house guests are roaming through Lawrence area residences this summer.

While you sleep, the tiny terrors wander over and under beds, through kitchens and bathrooms searching for prey. When the sun rises, they seek shelter in closets, behind cabinets, underneath couches and in clothes and shoes -- anywhere dark and uninhabited.

"They are everywhere," said Bruce Chladny, Kansas State University Research and Extension-Douglas County horticulture specialist. "They are dangerous. They are mobile and work their magic all over."

Prime time

Hank Guarisco, 52, Lawrence, who has studied spiders for 30 years in Lawrence, said brown recluse spiders live year round in homes but become active during the summer.

"The main reason you are seeing more recluses and a lot more bites is because it is hot," Guarisco said. "This time of year, they are much more active because they eat more."

Chladny said consecutive dry winters combined with substantial amounts of rain have produced prime brown recluse conditions.

Dr. Christopher Penn, an infectious diseases specialist, said he has treated more brown recluse bites this summer than the previous seven he has been in Lawrence.

Recluses do not attack humans; they bite as a defense mechanism.

"I have seen some very severe cases," Penn said. "There are some particularly bad bites this year."

Ryen Anderson, a 20-year-old Kansas University student, spent 48 hours under Lawrence Memorial Hospital care after being bitten while sleeping June 20. The bite left a 6-inch by 4-inch purple, blistered bruise on the back of his right calf that may require plastic surgery.

"It was really intense," Anderson said. "My chiropractor, who knows a lot about bodies, said he thinks that is as close to death as I will ever come."

Fatalities are rare, but are most common among children, elderly and people with poor health.

Recluses do not attack humans; they bite as a defense mechanism. The venom eats away the skin and muscle, according to Gaurisco. Many people don't know they have been bitten; the bite is often painless and, at worst, it feels like a needle prick. Other bites, however, cause intense burning from the onset.

Penn said there is no antitoxin for brown recluse venom. The most doctors can do is treat the effects: chills, fever, nausea, muscle pain and flu-like symptoms.

He said that bites take up to six months to heal and often require skin graft plastic surgery.

Anyone who is bitten by a brown recluse spider is advised to apply a cold-pack to the bite and see a doctor immediately.

Meet your guests

Brown recluse spiders are usually one-fourth to one-half inch in size with eight legs. They are usually yellowish-tan to dark brown. They live up to three years. The leg span is about the size of a half-dollar.

Guarisco said recluses are true house spiders because they can procreate and survive in homes.

They are found mostly in Midwestern states such as Texas, Kansas, Oklahoma, Missouri and Ohio. They are easily transported when people move. Brown recluses have been found in areas as far away as Maine, Arizona and Mexico.

Gaurisco said the recluses are difficult to distinguish.

"People can recognize them, but it is hard," Gaurisco said.

The brown recluse has been studied since the 1950s, but he said there is still much more to be learned.

Other findings

Lawrence residents may have help containing recluses. Gaurisco discovered the steatoda triangulosa spider, another house spider that preys on brown recluses, living in the area.

Gaurisco found 15 dead brown recluses in the cobwebs of steatoda triangulosa spiders in a Douglas County home he studied. The steatoda triangulosa is a spider who lives in cobwebs and can be found in between the walls and ceilings, often in kitchens.

Gaurisco plans to continue his research on the steatoda triangulosa and its effects on brown recluse spiders. In the meantime, he cautioned Lawrence area residents to be aware of the tiny creatures.

"It would be good to know if you've got them in your house and take measures to limit the possibility of bites," Gaurisco said. "It can be a problem, especially if you are bitten in a bad area."

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