Mindsuckers

Nature, first prize stories

December 8, 2013

Larvae of horsehair worms infiltrate house crickets when they scavenge dead insects, and then grow inside them. The cricket is terrestrial, but the adult stage of the worm’s lifecycle is aquatic. When the worm is mature, it alters the cricket’s brain, causing it to leap into the nearest body of water. As the cricket drowns, the mature worm emerges.

Many parasites not only feed off their hosts, but appear to manipulate the host’s behavior in a way that is advantageous to the parasite’s life cycle. Recent research indicates that this influence occurs at a genetic level—certain parasite genes seem to be able to take control of the host’s brain. Research has shown that in some cases a single parasite gene is responsible for altering the host’s behavior, though in most instances it is thought that the phenomenon is brought about by a combination of genes.

Commissioned by: National Geographic

Photo Credit: Anand Varma

Anand Varma is a freelance photographer and videographer who grew up in Atlanta, Georgia. He started photographing natural history subjects while studying biology at the University of California, Berkeley. His work tells the story behind the science on everything from primate behavior and hummingbird biomechanics to amphibian disease and forest ecology. He spent several years assisting David Liittschwager before receiving a National Geographic Young Explorers Grant to document the wetlands of Patagonia. He has since become a regular contributor to National Geographic and his first feature story, called ‘Mindsuckers’, was published on the November 2014 cover of the magazine. Anand lives in Berkeley, California.