Insects have more trouble identifying flowers to feed on when pollution and other odors get in their way, claims a new study.
Researchers from the University of Washington and University of Arizona looked at how tobacco hornworm moths interacted with plants in both clean and polluted air. The moths feed on the nectar of the Sacred Datura plant, but need to be able to fly hundreds of meters in order to get to them.
That means that they must rely on their sense of smell to know where the next flower will be.
The scientists used a proton transfer-reaction mass spectrometer, which detects different chemicals, in order to study the smells of different flowers in the wild. After that, they flew the moths in a wind tunnel that blasted them with a different variety of scents that varied in intensity.
The researchers found that the tobacco hornworm moths responded best to low levels of Sacred Datura odors, as opposed to high levels.
The researchers also found that in cases of clean air, the moths were able to identify the plants much easier. When pollutants were in the air, the moths had a hard time separating the smell of the pollutants from the smell of the flower.
Jeffrey Riffell, lead author, said: “Local vegetation can mask the scent of flowers because the background scents activate the same moth olfactory channels as floral scents.”
Riffell even noted that other man-made smells, such as the smell of car exhaust, also confused the moths.
“Nature can be complex but an urban environment is a whole other layer on top of that,” he added.
“These moths are not important pollinators in urban environments, but these same volatiles from vehicles may affect pollinators like honeybees or bumblebees, which are more prevalent in many urban areas.”
The researchers are planning on performing similar tests on other pollinators to see which chemicals impact an insect’s sense of smell the most.
The study was published in the journal Science.