Spiders may have entered Mazda cars before assembly, expert says

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Could new cars have come with spiders?

Mazda’s spider problem could be the result of an infestation by the venomous arachnid at an auto parts supplier or the Flat Rock, Mich., plant where the automaker assembles its Mazda6 cars, rather than at the garages of owners, an entomologist said.

This week, Mazda Motor Corp. said it would recall 65,000 cars to fix a problem with spiders nesting in tiny rubber hoses linked to fuel tank systems that could cause pressurization and ventilation problems in certain cars.

The Japanese automaker said the infestation by the yellow sac spider, or Cheiracanthium inclusum, could cause fuel leaks and even fires.

“It is a serious problem.... The gas tank could crack, and we want to make sure that every owner of a Mazda6 brings their car to a dealer and have it checked,” said Jeremy Barnes, a spokesman for Mazda North American Operations.


John Trumble, a UC Riverside entomologist, has an idea about when the spiders entered the fuel systems.

“These spiders are not getting into the cars while they are parked at homes,” he said.

Trumble said the spider is a “nocturnal hunter” that hides during the day and goes in search of prey at night.

“This is probably going on at some warehouse. The inside of a tube is the perfect place to spend the day waiting for night to go hunting,” Trumble said.

The spiders probably crawled into the tubes before some worker shipped the tubes to the assembly plant or placed them in cars, he said.

Barnes said Mazda believes the spiders are entering the vehicles after they leave the factory. He noted that one vehicle was at least two years old when the problem was discovered, and Barnes doubted that either the spider or the gas tank could have survived that long if the problem began before assembly.

“The tank is just not engineered for that type of blockage,” he said.

How the spiders got into the fuel systems remains a mystery, Barnes said.

Trumble said Mazda should check the tubes in storage at the factory and at any suppliers.

There are no reports of auto workers, mechanics or drivers being bitten by the spiders in the cars. And there are no reports of gas tanks cracking or of any accidents or injuries related to the problem.


The yellow sac spider is indigenous to all but the most northern states in the U.S. and accounts for a large percentage of spider bites in America.

According to an Ohio State University report, the spider is mildly venomous, causing a reaction similar to a mosquito bite, but can be more dangerous to some individuals. As with bee venom, some might experience “general systemic reactions that include fever, malaise, stomach cramps and nausea” and, in extreme cases, an ulcerated lesion that takes weeks to heal, the university said.

Mazda announced the recall after dealers around the country found 20 cases of the arachnid infestation. It includes 65,000 Mazda6 cars from the 2009 and 2010 model years in the U.S., Canada and Mexico. It seems to occur only in the four-cylinder version of Mazda6.

Dealers who find evidence of the spiders will clean out or replace the hoses and, if necessary, swap out the gas tank.

Pest infestations of vehicles are not all that uncommon. Messy, food-strewn vehicles are known to attract cockroaches, and there are reports of bees and wasps making nests in autos. Rats sometimes nest in the engine compartments of parked cars and chew away at the wiring.

A spokesman at the National Highway Traffic Safety Administration said the agency was not aware of any previous recalls caused by pest infestations.