Ridding Playground Of Hobo Spiders
My daughter’s preschool has a natural, landscaped outdoor play yard covered in bark chips for safety and includes some logs for balancing, jumping and encouraging creative play. A hobo spider with its funnel web was found under a log and my daughter is obviously concerned for her students’ safety. No pesticides have been introduced in this space — again, for obvious safety. How should she approach eliminating the hobos as best she can?
Multnomah County Oregon
"The hobo spider (Tegeneria agrestis, renamed in 2013 to Eratigena agrestis) was introduced to the Pacific Northwest United States in the 1930’s, and populations subsequently expanded throughout the region. The hobo spider is a large, brown spider that is easily and often confused with other funnel weaving spiders found in Oregon.5,6 The hobo spider is far less likely to be encountered than similar looking species (the domestic house spider and the giant house spider) in most parts of Oregon. Careful, close examination is required to tell the hobo spider apart from these other species. Not only is the hobo spider less likely to be encountered in Oregon than similar looking species, but research shows that hobo spider bites are highly unlikely to cause necrosis either due to venom or antibiotic-resistant bacteria. 2,7 In one U.S. study presented in 1987, the hobo spider’s venom was said to cause necrotic skin lesions in humans. Since then, however, numerous studies examining hobo spider venom have been unable to show skin necrosis. An analysis of patients claiming to suffer from spider bites found over 30 different health conditions associated with skin necrosis that patients or their doctors falsely attributed to spider bites. Research also shows no significant difference in chemistry between the venom of hobo spiders from their native Europe (where their bite is not a reported problem) and the venom of hobo spiders collected from Oregon and Washington. Lab studies likewise show no effect of hobo spider venom on mammalian red blood cells. Numerous spider experts have concluded that hobo spider venom does not cause skin necrosis, and cite misinformed medical professionals and urban legend as perpetuating this myth."