Fishing spiders in Ohio? It's true.

Arachnophobia, the irrational fear of spiders, is widespread. Some estimates claim that about 6% of the population are arachnophobes. If you are one, my apologies for this column. But you’ve probably already stopped reading.

Spiders are all around us. About 650 species are found in Ohio alone. Numerous species, most likely, are on your property and in your house. In warm seasons, a gentle rain of spiderlings wafts through the air. They disperse to new terrain soon after hatching by “ballooning”; sending out a silken strand that catches a breeze and takes them aloft. Fortunately for the arachnophobe, these spiderlings and the vast majority of spiders go unseen by most people.

Spiders are an important part of food webs – both as predator and prey – and engage in amazing behavior. Many are artistically painted in showy hues, or are ornate in their markings. Their production of silk and use thereof is highly advanced, and some species have the ability to spin incredibly intricate webs.

On September 7, 2013, I was with a group of colleagues late at night in the wilds of Adams County, Ohio. We were seeking caterpillars, and thus inspecting vegetation with flashlights. Suddenly, my beam picked up the eye shine of a big spider about twenty feet away and eight feet up in a redbud tree. I clambered up on some logs to get on the spider’s level, and was treated to the spectacle of a tarantula-sized nursery web spider guarding a nest.

I knew it was one of the fishing spiders, a group within the nursery web spider family. The family is so-named because the females create silken nests (nurseries) and guard the spiderlings for a week or so until they disperse. Many of the fishing spider species in this group are highly aquatic and can even catch small fish.

But this fishing spider was not like any I had seen. The head was a striking ivory-white, very different than the common fishing spiders that I was familiar with. I took photos, one of which accompanies this article. It didn’t take long to identify it: white-banded fishing spider (Dolomedes albineus). A later literature review showed no Ohio records of this southern species. Major excitement! A new spider for Ohio, and a particularly spectacular one!

A few weeks later I learned that another had been documented near Akron, about the time I found mine. Later yet, it came to light that a white-banded fishing spider had been found in 2012 in Perry County. The latter, discovered by moth expert Diane Brooks, was the first state record.

There is no question that white-banded fishing spiders are expanding northward. Spiders are not nearly so well known as birds or mammals, and thus the literature is often sparse. Still, several documents that mention this species from over a century ago describe it as a species of southern swamps, sometimes around cypress trees.

By 1973, white-banded fishing spiders had made it to Kentucky. A paper on fishing spiders published that year documented the northern limits of white-banded fishing spider as two southern Kentucky counties.

Fast forward to today. There are now dozens of records from Ohio, mostly east of a line from Cincinnati to Cleveland. There are also many records from Illinois, Indiana, Missouri, and Pennsylvania. At least one has reached the state up north, courtesy a 2020 record from southern Michigan. Apparently, all of the first records from all of these states date to within the last decade.

Why the recent expansion? Mean winter temperatures probably play a big role in defining the northern limits of white-banded fishing spiders (and many other insects and spiders). They overwinter as adults and can live for two years. As winters have gotten warmer, the spiders can expand their limits, and their quick expansion is abetted by the highly mobile balloon dispersal of the juveniles. Other factors may also be in play. Whatever the case, a very cool spider is now an Ohio resident.