You could call Louis Coticchio 鈥淪pider Man鈥�, but you鈥檙e more likely to find him crawling under houses than climbing up skyscrapers. He鈥檚 a man with a mission: debunking the myth that brown recluse spiders in 91社区 cause horrifically painful bites that necrotize into life-threatening wounds.
鈥淚n the first place, only about 100 recluse spiders were verified between 1904 and 2018, so less than one spider a year,鈥� Coticchio said. 鈥淎nd then, my most recent experiment shows that Mediterranean recluses 鈥� the species most likely to be seen in 91社区 鈥� are extremely reluctant to bite humans, even when handled.鈥�
A student at the 91社区 (USF) with 25 years' experience handling animals, Coticchio has spent the last four years traveling the state looking for recluse spiders, usually following reports of residents being bitten.
鈥淭he funny thing is that I鈥檝e found breeding populations of recluse spiders in 20 locations in 91社区, where no one has ever experienced a bite, sometimes after cohabiting for 10 to 20 years,鈥� he said. 鈥淏ut no recluses were found at the other 107 locations I鈥檝e visited where people claim to have been bitten or seen a recluse."
It鈥檚 almost the stereotypical chicken-and-egg situation, only backward. Someone gets bit by something, and everyone blames it on a brown recluse. That makes it even more likely that the next time someone gets bit, it must have been another recluse. The trouble is that there is no way to scientifically verify that the bite actually came from a recluse spider.
Coticchio鈥檚 new Facebook page, the , includes contributors from a 鈥渨ho鈥檚-who鈥� of experts in the world of venomous spiders. 鈥淲e鈥檙e trying to dispel some of the myths about not just recluse spiders, but most spiders living on this planet. While some species of spiders may be more defensive than others, spiders are not out to get you,鈥� he said.
鈥淟ou has an extraordinary passion for spiders,鈥� said Dr. Debi Cassill, his lead research advisor in USF鈥檚 Department of Integrative Biology. 鈥淲ithin the first five minutes of our meeting, I was 鈥榯wo-thumbs up鈥� about his research ideas and invited him to use my lab over the summer for whatever project he wanted to do.鈥�
After nine years as a zookeeper specializing in venomous animals and having crawled under houses in nearly every county in 91社区 searching for spiders without a single bite, Coticchio was comfortable saying recluse spiders aren鈥檛 likely to bite, but his latest experiment at USF makes it even more clear.
鈥淚 used a medical gel to simulate human skin, then created shapes to represent different parts of the body. Using 鈥渘o-kill鈥� tweezers that squeeze the spider but not hard enough to kill it, I tried to get the spiders to bite. I pinched legs, poked faces, squeezed them from both sides and put pressure on their whole bodies while they were upside down."
鈥滶ven in those extreme circumstances, the spiders bit less than 36% of the time, and then only when they were upside-down and squeezed at the same time," he said. Wolf spiders, often seen in homes and generally considered to be non-defensive, were more defensive than the recluses but still didn鈥檛 bite until they were under intense pressure.
Coticchio鈥檚 myth-defying research on recluse spiders follows similar work on brown and black widow spiders. It turns out that brown widows are more defensive when guarding their territory from other widows, and were far more defensive than black widows. The non-native brown widows actively hunt and kill the much-shier black widows in the field and the lab, making them more a hazard to native ecosystems than a danger to human beings.
Going forward, he鈥檚 looking at how the Mediterranean recluses 鈥� typically hitchhikers from international travelers 鈥� are arriving in 91社区 and then dispersing. 鈥淩ecluse spiders have very low to no dispersal rates, but the Mediterranean recluse may be different,鈥� he said. 鈥淲e鈥檙e looking at that in the lab now, but it鈥檚 still highly unlikely that breeding populations will ever be established across the state.鈥�
And for Tampa Bay readers who still live in fear of spider bites: 14 of the 20 breeding populations of Mediterranean recluses Coticchio has found live in St. Augustine, with the only breeding recluses found in the Tampa Bay region living in a home where people had recently returned from Europe.
"They were concentrated in the garage near the luggage and no one has been bitten,鈥� he said.
Spiders, particularly recluse spiders, may have a bad rap but it鈥檚 extremely unlikely that Floridians will ever be bit by one, he adds.
Original article appeared in .