Understanding Iowa Spiders

Oct 18, 2019

By mid fall, spiders gain their most visible presence as they reach full maturity, build larger webs, and prepare to lay their egg sacs for the spring. 

ISU Professor of Entomology Donald Lewis joins Talk of Iowa host Charity Nebbe for this weekly edition of 'Horticulture Day.' He shares facts, debunks myths, and offers words of appreciation about spiders.

"All spiders are predators that are feeding on other critters: things that we don't want in the house, things we may not want in the garden," Lewis says. "We should love spiders, we should be grateful for the biological control services they provide."

Lewis says some of the most common spiders found in Iowa are brown wolf spiders, orb weaver spiders, grass spiders, and cellar spiders, all of which are not harmful to humans. He says the most dangerous spider likely to be found in Iowa is the brown recluse spider, which can cause non-lethal necrosis from its venom. Black widow spiders are also rare but present across Iowa.

Later on, Lewis and ISU horticulture extension specialist Richard Jauron answer calls and emails from listeners about the plants, trees and insects in their lives. 

Guests include:

  • Richard Jauron, Iowa State University horticulture extension specialist
  • Donald Lewis, Iowa State University professor of entomology