The bloodsucking insect with a saw for a mouth: How the tsetse fly bites through almost anything

Tsetse flies, notorious bloodsucking insects, employ a unique feeding strategy that allows them to penetrate a wide range of skin types with remarkable efficiency. These insects transmit diseases like sleeping sickness, which poses a threat to human health, livestock production, and rural development across sub-Saharan Africa. The tsetse fly's feeding apparatus, equipped with rows of tiny teeth and a labellum with a labellum, enables it to pierce various skin types, including soft mammalian skin and tough reptilian scales.

Instead of relying on a single specialized tool, the fly's success lies in a combination of anatomy, mechanics, and behavior. During feeding, the fly opens the labellum inside the skin, exposing its teeth, while repeatedly pushing and pulling its proboscis through the tissue. The forces generated during the backward strokes are stronger than those used to push forward, acting like a cutting motion to drag the teeth through tissue and enlarge the feeding site.

This versatile approach allows tsetse flies to overcome diverse physical challenges and effectively transmit parasites among wildlife, livestock, and humans.