Ghouls and ghosts may take the spotlight this time of year, but for people in Colorado, it’s the cat-faced spider that might cause the most fright. The regional spider, known for its protruding horns that resemble the ears of a cat, drops an egg sac in the fall, which means come Halloween they’re at their plumpest size.
For the last 11 years, Whitney Cranshaw, professor of bioagricultural sciences and pest management in Colorado State University’s College of Agricultural Sciences, has held a contest to find the biggest cat-faced spider (Araneus gemmoides), and this year, the entry farthest from Fort Collins in the history of the contest was also the largest ever submitted. Dubbed “Princess Raya” by Raya Davis Thompson, a 9-year-old girl from Lamar, Colorado, it clocked in at a whopping 3.75 grams, roughly 25% larger than the previous record holder, “Arach Obama.”
“Little kids getting into spiders,” says Cranshaw. “It’s a rarity, and she knocked it out of the park.”
Our region’s Charlotte’s Web
According to Cranshaw, the cat-faced spider is the most common representative of the spider genus Araneus in Colorado, a type of orbweaver spider. It is Colorado’s regional representative of this spider group that in the Midwestern U.S.would be represented by the “barn spider” Araneus cavaticus, which happens to be the spider that inspired the book Charlotte’s Web.
“This is a not uncommon spider, and people can see it around their homes,” says Cranshaw. “It’s odd looking, so there’s a lot of anxiety about it. People worry about things that look strange.”
The spider is most often seen within a web constructed on the sides of buildings, commonly around windows where nighttime light helps bring in insects.
Origins of the contest
Cranshaw started the contest as a way to reduce anxiety about the common spider. As the female spiders grow in size prior to laying an egg sac, they can appear quite foreboding to those unfamiliar with them.
“[People] assume the worst,” says Cranshaw. “The contest is one of several things I try to do to make people in Colorado more familiar with arthropods, so they can approach them more rationally.”
Unfortunately, this Halloween does deliver on its promise of doom. Cat-faced spiders die after delivering an egg sac, and “Princess Raya” passed on a few days before.
As for the contest, this year also might be its last. Cranshaw is planning to retire in the summer, and admits this will probably be the last time he calls for entries.
“This is a high note, and I’m going to end it on this one,” says Cranshaw. “This will be the last time, and I like the way it ended.”
