While humans spend sticky summer months trying to get rid of mosquitoes, a certain sort of orchid is doing all it can to attract them. Known as ‘masters of deception,” an orchid’s thirst for pollination gets real enough that they’ll disguise themselves as a female bee or attempt to smell like rotting meat.
Now, a new study has found that in order to bring all the mosquitoes to their yard, some orchids will do something different altogether: They’ll smell like humans.
Sensory biologists have discovered that a particular sort of orchid, the Platanthera obtusata, emits an odor that smells like people to attract tiger mosquitoes:
The flower, a bog orchid that is common in the United States, relies on the mosquito as a pollinator. While humans can barely detect the smell in our own noses, the fragrance — which includes chemicals found in human body odor — stimulates electrical activity in a mosquito’s antennae, creating attraction.
This new research was presented Monday at the 2016 annual meeting of the Society for Integrative and Comparative Biology. In their presentation, researchers from the University of Washington explained that female mosquitoes don’t just feed on blood to produce eggs — they need carbohydrates to sustain their metabolism as well. The mosquitoes head to the orchids to get a carb load, while the orchids rely on the mosquitoes for pollination. But until this discovery, researchers did not know why mosquitoes were compelled to dive into the P. obtusata.
After observing mosquitoes hovering about the orchids, the researchers analyzed scent samples from the species and identified which specific compounds of the scents mosquitoes were reacting to by delivering pulses of the chemicals to the insects. The result: Mosquitoes buzzed over to the orchids because of the same chemical components that make them fly to us.
The researchers plan on continuing behavioral tests on the mosquitoes and believe that identification of these chemicals could lead to the creation of new bait for mosquito traps.