Untangling the web

Along with collecting data, researchers conducting a survey of spiders in Ohio want to help people better appreciate the little eight-legged guys.

Richard Bradley

Published in the May/June 2011 issue of Ohio State Alumni Magazine

by Lawrence Houck
photo by Chris Crook

 

Entomologist Richard Bradley says spiders are “charismatically challenged.”

Their creepy reputation is unfair, he believes, but perhaps understandable.
“Most spiders are nocturnal, which I think is one of the reasons they’re scary to people,” said Bradley, an associate professor at Ohio State’s regional campus at Marion. “Things that come out at night tend to be scary.”

Much of Bradley’s work has gone toward showing that spiders are more fascinating than terrifying. Back in 1994, he launched an ambitious survey aimed at filling in the huge gaps in knowledge about the state’s spiders.

The Ohio Spider Survey relies in part on volunteers, and that involves getting the word out about the important role spiders play in nature. “It’s teaching people to appreciate spiders. I don’t expect people to like them, but I want them to understand their importance to the ecosystem,” Bradley said.

They’re everywhere!
Most of what scientists previously knew about Ohio spiders came from a study and an addendum published in 1919 and 1924 by William M. Barrows, a professor of zoology and entomology at Ohio State.

His work was a great start but far from comprehensive, Bradley said. Barrows listed only 306 species of spiders living in Ohio. Some 630 species have been identified since then, including 220 found as a result of Bradley’s survey.

“It’s not like a whole bunch have been moving in,” he said. “They just hadn’t been discovered.”

To encourage volunteers to scour their homes and gardens for spiders, Bradley launched a Web site where people can learn how to collect and document specimens.

Samples have come in from locations across the state, from suburban backyards to farmlands and hedgerows. Some of the most important research takes place in nature and wildlife preserves, which remain closer to the original state of the land.

“We’re trying to get samples to see what spiders were there before human development. It’s a good chance to see what their habitat was like originally,” Bradley said.

The survey documents not only what spiders are in Ohio, but where they live. “There are a few species that haven’t been found anywhere near here before,” said Bradley.

Because most spider species have a fairly broad range, those in Ohio typically are not unique to the state—with one exception. Tapinocyba emertoni lives in the Cantwell Cliffs area of Hocking Hills State Park and nowhere else in the world, as far as anyone knows. T. emertoni was discovered in 1928 and last recorded in 1938—until it turned up in the Ohio Spider Survey in 2000.

“It’s just a mystery as to why it’s in only one spot,” Bradley said. “Maybe there is something really special about the chem-istry of the soil.”

 

A kinder, gentler reputation
Bradley’s spider survey is not the only research that’s been done at Ohio State on the eight-legged creatures.

Most spiders eat only insects. Robin Taylor, an instructor in the Center for Life Sciences Education, learned that some spiders in the tropics also feed on nectar.

“There had been anecdotal reports of that before, but nobody had done a systematic investigation,” Taylor said.

Her research from the late 1990s through 2000 showed that certain spiders can meet a significant amount of their dietary needs through extrafloral nectaries: nectar-bearing tissues that are outside of a flower—on leaves, for example.

“Many, many spiders are engaged in nectar feeding regularly,” Taylor said.
Her finding is significant because the ability to survive primarily on nectar means the spiders might be able to avoid their larger predators.

“It’s not just about not having to go out and get prey, but it’s what you avoid by not having to go out and get prey,” she said.

Like Bradley’s work, Taylor’s research illustrates the variety of existing spiders. “When people think of a spider, they think of a big thing hanging in a web, but spiders engage in other strategies for getting around and capturing food,” she said.

She acknowledges that the fact that some spiders prefer nectar to prey does little to calm fears. People often ask her about unexplained bumps and marks that they think might be due to spiders.In reality, spider bites are fairly uncommon, Taylor said. Spiders don’t roam your house in search of a meal.

“The spiders that are wandering around are usually outside. The ones that do get in our houses are usually the cellar spiders that stick in one place,” she said.

Bradley also gets lots of questions—some 1,200 are submitted to his Spiders in Ohio Web site each year. Among the most common: “Is the spider I found in my home poisonous?” In almost every case, the answer is no. “People think whatever they have must be deadly,” Bradley said.

In fact, spiders play an important role in pest control. Rather than fearing them, perhaps people should be thankful.

“If you have a lot of spiders, it’s probably because you have a lot of food,” Bradley said.
 
Find a spider?
The Ohio Spider Survey continues to accept specimens found in the field; however, the focus of the study has moved from collection to identification.
To learn how to submit a spider, visit the site below and click on the “Ohio Spider Survey” link. The link “How to Study Spiders” provides information about preserving spiders and recording data.

Ohio Spider Survey
www.marion.ohio-state.edu/SpiderWeb


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

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