Spiders and car recalls

In the news today is an interesting story about spiders. Apparently, there have been 20 reports of spider webs found in a part of 4-cylinder Mazda6 sedan fuel systems. Now 52,000 of these cars are being recalled, as the vent lines these webs are in can cause blockage and ultimately cracks in the gas tank. This could result in a fire, though none have been reported.

The spider culprit? Most news reports I can find refer only to "a yellow sac spider," a term which can refer to a few different species in the genus Cheiracanthium. US Recall News specifically sites Cheiracanthium inclusum, but as they readily indicate in the article their source of spider information is Wikipedia (i.e. not always informative or correct). C. inclusum is one of the few medically significant spiders in the United States, so it's little surprise (to me at least) that this particular species would be targeted first.

Cletus Lee Flickr

C. inclusum is a native spider often finds its way into homes and may be the most common cause of spider bites. The bites normally cause just local pain and a wound which should heal in a few weeks.

Whether the Mazda spiders are C. inclusum or C. mildei (another very common yellow sac spider which is invasive from Europe), I wonder why they are making webs in car innards. I'm not sure how small the vent is, but yellow sac spiders make webs for hiding out in rolled up leaves. They are otherwise active predators.