MARION, Ohio - They are spindly creatures capable of striking fear in even the most stout-hearted and often regarded as unwelcome pests.
But spiders are thought to provide a sensitive measure of ecological health by those who study them and they are undoubtedly the most important natural predator of insects.
Little research to identify species and distribution patterns of spiders has been done in Ohio until a new study was launched five years ago by Richard A. Bradley, associate professor of evolution, ecology and organismal (EEO) biology at Ohio State University.
Part of this research effort has been to create the Ohio Spider Survey, a collection database consisting of the various types of spiders and their distribution known to occur in the state. The database contains information on 520 species of spiders, which includes the identification of 217 species, since 1994, that are new to Ohio.
"We are working with many students and volunteers on this project," said Bradley. "I have collected specimens that have not yet been identified because this process takes so much time. Many of these spiders are quite small and are similar in appearance to some other species."
It^s estimated as many as 700 species of spiders may be present in Ohio.
While all spiders are venomous, a few species have been known to bite humans, sometimes inflicting a severe injury but rarely a fatal one. Among these are spiders such as the black widow, northern widow, brown recluse, dysdera, and yellow sac spiders.
"Only three widow spiders have been collected among 10,000 specimens, so they are quite rare in central and northern Ohio, but they would be more commonly found in outdoor privies and likely in the area of southwest Ohio. Spider bites that result in deaths are extremely rare in the U.S. and more than 80 percent of suspected spider bites turn out to be bites from something other than a spider, such as an insect," said Bradley.
Another aim of the study is to include research professionals and volunteers for documentation
of spider diversity in Ohio. By learning more about Ohio^s spider community, it is expected that educational materials may one day be developed to help explain how spiders function in natural habitats and why they should be respected, but not feared.
Among these educational materials is a new book titled "In Ohio^s Backyard: Spiders", which is now being written by Bradley, who expects it to be published late next year or early in 2001.
"I^m quite interested to be able to identify which, if any, species of spiders are important to agriculture," said Bradley.
"Much of the spider research today is on how to prevent an outbreak of pests, but I want to look at some possible management techniques that are instead focused on how to get spiders to invade agriculture fields when they would be most beneficial to agriculture. I would also like to obtain some information about any potentially threatened or endangered species of spiders."
One of these potentially threatened species is a large wolf spider named "Geolycosa". This is a burrowing wolf spider that prefers soft, sandy substrates, few of which exist in Ohio. Its body length is 1 to 1 1/2 inches long with legs that span 2 to 2 1/2 inches.
"Geolycosa appears as a very large spider, but most species of spiders as adults are less than 1/4-inch or even 1/8 inch in size. I would estimate that the average suburban yard in Ohio has at least 50 or more different species of spiders present, most which are so small that you would need a magnifying glass to see," said Bradley.
Though many people will not likely change their long-held opinions for disliking spiders, gaining a better understanding for their role in nature may lead to an increased appreciation for their existence. Bradley^s research is supported through cooperation with the Ohio Biological Survey and Ohio Division of Wildlife. A portion of the funding used in this spider research comes from taxpayer contributions to the wildlife agency^s income tax checkoff program for wildlife diversity.