In the understory of a tropical forest, a carpenter ant has descended from the canopy away from her regular foraging trails and staggers drunkenly along a branch. Her movements are jerky and conspicuous. She twitchily moves forwards and suddenly starts convulsing with such ferocity that she falls from the branch onto the ground before resuming her erratic, zigzaging path. This is a “zombie ant”, and she’s unwittingly become part of the lifecycle of a parasitic fungus commonly known as Cordyceps.
Around noon, after several hours of climbing and aimless lurching, the ant is now no more than about 25cm above the ground, crawling aimlessly on the underside of a sapling leaf where, without warning, she forcefully sinks her powerful jaws into one of the leaf’s veins, gripping it firmly between her tightly locked mandibles.
Within six hours, she is dead. After two days, white hairs bristle from between her joints and a few days later these have become a thick, brown mat covering the whole insect. A pinkish-white stalk starts to erupt from the base of the ant’s head and continues to grow. Within two weeks it has reached twice the length of the ant’s body reaching down towards the ground below. MORE
Header image: Cordyceps infected ant from Sabah, Borneo, Malaysia. Credit: Gino Brignoli.