Because smell is essential to mosquito survival, each mosquito has three pairs of “noses” for sensing odours: two antennae, two maxillary palps and two labella.
The maxillary palps are thick, fuzzy appendages that protrude from the lower region of the mosquito’s head, more or less parallel to its proboscis, the long, flexible sheath that keeps its “feeding needle” under wraps until needed. At the very tip of the proboscis are the labella, two small regions that contain both “gustatory” neurons that pick up tastes and olfactory neurons for recognising odorants.
This image shows a female Anopheles gambiae mosquito with olfactory neurons on her antennae, maxillary palp and labella labeled in green. For more, see a paper published in Nature Communications.