🚨 ARTHROPOD OF THE DAY 🚨

Joro spiders are big spiders about the size of the tip of your thumb. Their long skinny legs can reach a span of 3-4 inches. Instead of being all black or all brown like most spiders, their females are very colorful. Their backs are black with yellow stripes and a red splotch, there are red markings on the stomach as well. Joro spiders have striped legs, with bands of yellow and blue. Besides their color what makes them stand out is their giant golden webs. They are part of the orb-weaver family and can weave large intricate 3-D webs.

In 2014 people reported seeing this unusual spider and their enormous webs in Georgia. Scientists confirmed that it was the East Asian Joro spider. It is unlikely they ballooned across the ocean to get here. Scientists think it is most likely that these spiders hitched a ride on a shipping container and started reproducing here. It is likely that they used the ballooning technique to disperse through Georgia and South Carolina.

The majority of ballooning is done by spiderlings. A few days after hatching, large groups of baby spiders will take to the air. Their main purpose is to spread out and find new places to live but they also do it to avoid cannibalism from other spiders and to increase the availability of resources.

Ballooning spiders operate within the planetary electric field. When their silk leaves their bodies, it typically picks up a negative charge. This repels the similar negative charges on the surfaces on which the spiders sit, creating enough force to lift them into the air. And spiders can increase those forces by climbing onto twigs, leaves, or blades of grass. Plants, being earthed, have the same negative charge as the ground that they grow upon, but they protrude into the positively charged air. This creates substantial electric fields between the air around them and the tips of their leaves and branches—and the spiders ballooning from those tips.