Study Uncovers Olfactory Switch That Turns Young Female Mosquitoes From Nectar Seekers to Blood Feeders

A new laboratory investigation has identified the sensory mechanism that drives young female mosquitoes to abandon nectar and begin hunting for blood, a shift that underpins their role as disease vectors.

Researchers focused on the odor‑receptor repertoire of Aedes aegypti and discovered a specific receptor that is highly responsive to the volatile compound camphor. When this receptor is activated, it triggers a cascade of neural signals that rewire the insect's feeding preferences, prompting a transition from plant‑derived sugars to vertebrate blood.

The study builds on decades of work showing that mosquito behavior is largely dictated by smell. Mosquitoes locate hosts by detecting carbon dioxide, lactic acid, and a suite of skin odors, while nectar sources are identified through floral scents. By pinpointing a single receptor that flips the dietary switch, scientists now have a clearer picture of how the insect’s olfactory system prioritises blood after a certain developmental stage.

Experiments involved genetically silencing the camphor‑sensitive receptor in newly emerged females. Those mosquitoes continued to feed exclusively on sugar solutions and showed little interest in blood meals, even when presented with a warm, carbon‑dioxide‑rich host. Conversely, restoring the receptor’s function reinstated the typical progression to blood feeding within days.

The findings have practical implications for vector‑control strategies. If the receptor can be blocked or its activation delayed, it may be possible to keep female mosquitoes in a sugar‑feeding state, reducing their capacity to transmit pathogens such as dengue, Zika, and malaria.

Future work will examine whether similar olfactory switches exist in other mosquito species and explore chemical compounds that could safely interfere with the receptor in field settings. Understanding the precise sensory cues that drive blood‑feeding behavior could open new avenues for disrupting the life cycle of these globally important pests.