This killer fungus strikes at sunset. Here’s how

The Sunset Zombie Fungus: A Deadly Precision

No, this fungi-infected fly did not just step out of a bubble bath. The white, sudsy looking structures erupting from the insect's back are for launching fungal spores.
Credit: Carolyn Elya Lab

Entomophthora muscae is a parasitic fungus that transforms fruit flies into "zombies," compelling them to die at sunset. Once infected, the fungus infiltrates the fly's body, spreading to the brain and manipulating its behavior. The fly climbs to an elevated surface, attaches itself, and dies with wings extended, allowing the fungus to launch its spores into the environment.

For years, scientists were puzzled by the consistent timing of the fly's death. Recent research led by Carolyn Elya at Harvard University has uncovered that the fungus possesses its own internal clock. Experiments with genetically modified flies, including those with disrupted circadian rhythms, showed that the timing of death remained unchanged, indicating the fungus controls the timing, not the fly. Additionally, the fungus exhibits daily cycles of gene activity, even in complete darkness, further supporting the presence of an intrinsic biological clock.

This discovery sheds light on the sophisticated mechanisms fungi employ to ensure their propagation, highlighting the intricate relationships between parasites and their hosts.