2015 Photo Contest, Nature, 1st prize



Anand Varma

National Geographic

08 December, 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.

About the photographer

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 Universi...

Technical information

Shutter Speed
Focal length
50.0 mm
Canon EOS 5D Mark III

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