A cargo ship filled with bananas arrives in a U.S. port.  As workers begin to unload, a huge spider is found bearing furry red markings and glaring eyes.  Is the spider dangerous?  Should the whole shipment be dumped?  Fearing the arachnids could be deadly, crews often collect the spiders and send them to specialists for identification while the fate of the cargo sits and potentially spoils.  It’s a costly and often unnecessary problem, according to University of California archeologist Richard Vetter. 

Vetter studied 135 spider specimens found among international cargo shipments between 1926 and 2014, and published his research to the Journal of Medical Entomology.  Sometimes crews think the spiders have medicinal value and send them to hospitals.  But most often, without knowing if a species is dangerous, they worry their load of bananas has been spoiled by the creatures.  But, Vetter found there’s no need abandon your curds and whey—just yet. 

“Spiders found in international cargo, especially those in banana cartons, are typically harmless species,” they wrote. “ It would be beneficial if this article curtails the hyperbole and media attention whenever a large spider is discovered in a banana shipment, and thereby, reduce unwarranted paranoia and anxiety when media stories about toxic banana spiders are unleashed onto an unsuspecting and easily frightened North American general public.” 

While hitchhiking spiders may not be dangerous to humans, other invasive species traveling over in international shipments can cause widespread environmental damage.  The Asian Gypsy Moth is much less intimidating than a spider in person, but the little beasts defoliate an average of 700,000 acres of U.S. foliage each year.  Last November, the PBS NewsHour profiled the Asian tiger shrimp, which threatens to change the balance of wildlife in the Gulf of Mexico.