The Magical Jumping Wasp Galls of Chico, California

Every year around the Fourth of July an interesting phenomenon happens underneath the Valley Oaks in Northern California. In July, 2020 the wasp galls in Chico, California seem particularly abundant. There are millions of them. They are easiest to spot on pavement, curbs and sidewalks where they accumulate in dips, crevices and low spots.

A couple details that I didn’t make clear in the video: the “jumping” is caused by the wasp larvae vigorously moving inside the gall. In fact if the larvae was the size of a human, we’d be able to jump 20 feet high. Also, the tiny wasps (there are over 1300 species) are harmless to humans. No stingers. They seem to have one purpose: reproduction. No males are required. This maleless process is known as parthenogenesis.