Peak of spider season in the Treasure Valley

Credit: Theresa Palmgren / KTVB

A small spider hides near a plant at KTVB photojournalist Theresa Palmgren's home.


by Bonnie Shelton

Bio | Email | Follow: @BonnieKTVB


Posted on September 4, 2013 at 5:14 PM

Updated Thursday, Sep 5 at 2:26 PM

BOISE -- They're creepy, crawly, and experts say a lot they're on the move. That's because it's the peak of spider season in Idaho.

Scientists say many species of spiders are typically on the move during this time of year -- but they're not looking for you -- they're looking for a mate.

However, even people who study the arachnids for a living admit it's not always fun to come across one during this active time.

"I don't have a huge fondness for spiders," said Boise State Biology Professor Ian Robertson. "My expertise is in entomology and insect ecology."

Robertson knows the habits of spiders well. He says many species are currently looking to reproduce, and may be headed indoors.

"The day lengths are getting shorter, the nights are getting cooler, and spiders often seek refuge in houses," said Robertson.

Exterminators from Gemtek in Boise told us they're seeing an increase in calls from homeowners who want to keep spiders out of their homes.

"It's been a hot summer --dry, perfect conditions for them to do what they do, and increase their populations," said Kip Roberts, a Gemtek technician.

Roberts uses a plant-based spray around door frames and other crevices to keep eight-legged creatures out.

"We put a barrier around the home," said Roberts.

Experts say only two types of spiders that live in Idaho are poisonous, including the black widow and the hobo spider.

"Hobo spiders tend to stay low to the ground, usually away from open areas," said Roberts, adding that this kind of spider is often misidentified. "Hobo spiders don't have any stripes on their legs."

If you think you've been bitten by one of those two spiders, see a doctor immediately.

Despite their venom and less-than-friendly looks, experts said your first instinct shouldn't always be to kill a spider when you see one.

"They're just a natural part of the ecosystem," said Robertson.

In fact, he said some will kill other spiders for you.

If you still dislike the creepy crawlers take note, the spider season ends in October when the weather gets colder and spiders hunker down for the winter.