By DEREK FAY
Say the name “black widow,” and you can get most people to shudder as they picture the poisonous little arachnid that has inspired everything from horror stories to tattoos.
Mention the name “hobo spider,” and the most you will usually get are wrinkled brows and inquisitive looks. However, this eight-legged relative newcomer to Utah is making a name for itself, and is starting to be respected among entomological bad boys (or in the black widow’s case, bad girls).
Last year, the hobo spider, or aggressive house spider, became the third spider to be officially placed on the venomous spider list of the Centers for Disease Control and Prevention in Atlanta. It was introduced into the United States sometime before 1930 in a port in Seattle, according to Dr. Darwin Vest, a research toxinologist in Idaho Falls, Idaho. In 1990, the spider was discovered in Utah and has started moving south. It has been reported in 11 counties, including Salt Lake and Utah counties, said Alan Roe, insect diagnostician for the Utah State University Biology Department.
What’s all the fuss? Well, these nickel-sized, violin shaped, brown spiders deliver powerful bites that rival those of any poisonous insect alive.
“A lot of spiders inject venom and it’s not a problem,” Roe said. “It so happens that this venom is.”
The venom from a hobo spider bite usually causes a large area of redness which disappears after a few hours, leaving a bump similar to a mosquito bite. Within 24 to 48 hours, blistering may occur which ruptures, leaving an open wound. This type of wound, called a nechrotic lesion, can take anywhere from weeks to months to heal.
“It is a spot that won’t heal, essentially,” Roe said. “It may take six months to heal.”
Bites can be more hazardous, even deadly, to small children and infants.
“There is evidence that smaller individuals suffer from it more,” Roe said.
More serious symptoms can include fevers, vomiting and headaches that don’t respond to analgesics.
Recent media attention has been focused on the spiders because it is prime spider season. Right now conditions are perfect for hobos and some other spiders to thrive. Because of their life cycle, most hobos will be seen between late August and early October, said Frank Zabrotzky, environmental specialist for the Salt Lake City and county health departments.
Recently, Utah news anchors have donned concerned expressions as they have recited stern warnings about steering clear of the infamous “aggressive house spider.” This moniker, which is the unofficial name of the hobo spider, has spawned several myths. Stories have been told of hobos attacking people “for no good reason,” simply because hobos are, well, jerks.
This is not true according to some entomologists.
“They look like they are attacking because they are running at you. They are trying to get away and they keep going,” Zabrotzky said.
“This business about being aggressive — frankly, I don’t believe it,” Roe said. He said that if they do attack, it’s most likely in self defense.
Hobos are mostly found on the floors and in basements of homes, a fact that will disturb squeamish college students in Provo who happen to be living in basements.
“About two-thirds of (encounters) come from the basement,” Roe said.
For those arachnophobics who wish to protect themselves, common sense can be the first line of defense.
“It’s a housekeeping matter,” said Carol Rowberry of Rowberry’s Termite and Pest Control in Provo.
Simply vacuuming areas behind furniture and other places will keep hobos at bay, she said.
To keep from being bitten, an article by Vest suggests that a person wear long protective clothing while working in the basement or garden. Although hobos don’t like to climb, they will. Keeping the bed covers from touching the floor can prevent the spiders from ascending into the sheets where they have a tendency to bite people who roll over on them.
Despite their snowballing infamy, some people concede that hobo spiders get a bad rap sometimes.
“It’s a media-controlled situation,” Rowberry said. “People need to stop being made afraid by the media. They need to be educated.”
She said every time hobo spiders are mentioned in the news, telephone calls flood her pest control office. Most of the people who call think they have hobos in their house but usually turn out to be mistaken, she said.
Roe also believes that although people should be aware of the spiders, there is no need for panic.
“You don’t want to get bit by one, but it isn’t anywhere near as life-threatening as a black widow, and (a black widow) is not all that threatening,” Roe said.
Hobos build funnel-like webs and have a few characteristics that help distinguish them from other spiders in the home. They are about 12mm to 18mm in size and have unmarked legs. They have “chevron” patterns that can usually be seen on their backs and males have two “pedipalps” which look like protrusions with small boxing gloves on the ends, growing out of their face.
Vest suggests taking a specimen to a qualified arachnologist for identification if there is a question about what type of spider has been found in the home.
