Moisture is as crucial as aroma in attracting pollinators to a plant, according to a new Cornell study that improves basic biology and creates new ways to boost agriculture.
In a study published in Current Biology, a team of Cornell researchers and colleagues from Harvard University and the Montgomery Botanical Center found that the weevil responsible for pollinating the Zamia furfuracea plant was as sensitive to moisture as it was to scent.
“The world of plant-insect interactions has changed drastically because of the work that has been done on visual and olfactory cues,” said first author Shayla Salzman, a National Science Foundation postdoctoral fellow in the College’s School of Integrative Plant Science Plant Biology. agriculture and life sciences.
Dahake was the first author of a groundbreaking study published in 2022 in Nature Communications that found that moisture acts as a signal that encourages hawks to pollinate the sacred Datura flower (Datura wrightii). Overall, the studies show that the two very distantly related plants actively use moisture to promote pollination, Dahake said.
“Prior to our research, moisture was only seen as a result of nectar evaporation, a side note,” he said. “We found that this is an active flowering process that goes through specialized cells, and these organisms may have even evolved to favor the release of moisture because it attracts pollinators.”
Until now, the study of pollination and plant-insect interactions has focused on visual and olfactory markers—senses that can also be interpreted by humans. But insects are much more adept than humans at sensing changes in humidity, carbon dioxide and temperature, Salzman said.
“Especially because climate change directly affects these very things,” she said, “it’s critical that we understand how insects use all of this information in their interactions with plants.”
For example, farmers and food distributors could use the information to promote pollination of food crops or direct insects away from stored food and into traps, Salzman said.
While humans need relatively large changes in humidity before we can feel the difference, insects can sense minute changes, Dahake said.
“Insects have specialized receptors that respond to very small changes in humidity: Even a change of 0.2% to 0.3% causes a neuron to fire,” he said. “Even a 1 part per million change in carbon dioxide concentration will cause the insect’s neurons to respond. What does this mean behaviorally? We are just beginning to scratch the surface.”
