What Can Mosquitoes See?

Until now, scientists didn’t know what can mosquitoes see. Mosquitoes have two compound eyes and use several senses to “see” their surroundings. They can see outlines, shapes, and motion. They can also detect heat and carbon dioxide.

To determine what can mosquitoes see, scientists studied a mosquito called Aedes aegypti. Aedes aegypti is a diurnal mosquito, active during dawn and dusk. It is also known to carry disease. It has 10 rhodopsins. These rhodopsins are orthologs of medium-wavelength-sensitive opsins. It also has a mutant gene that affects color vision.

In order to determine what can mosquitoes see, scientists built a test chamber. The chamber was 450 mosquito body lengths long and had colored disks on the floor. The chamber was lined with cameras that recorded flight patterns. They also had a video projector that projected visual stimuli. The test chamber was designed by Diego Alonso San Alberto, a software engineer from the University of Washington.

Researchers tested the mosquitoes’ visual responses to moving objects. The moving bars were positioned with a 19-deg wide bar that moved clockwise. The bars had a peak at 455, 547 nm, and 633 nm. The bars were tested ten to thirty times per mosquito.

Researchers also recorded electroretinograms from the mosquitoes. These electroretinograms showed that mosquitoes showed a strong response to green wavelengths. They didn’t show a strong response to blue, violet, or other dominant wavelengths.

The researchers also tested the mosquitoes’ response to CO2. CO2 is a gas that humans exhale. When mosquitoes smell CO2, they boost their activity. They then search for hosts.