Biologists have found that plants respond to the sound of an approaching insect by rapidly releasing nectar that attracts pollinators.
The union of plants and pollinators is hundreds of millions of years old, but we are only now beginning to realize all its complexity. New work by biologists from Tel Aviv University has revealed another side of this relationship. So, in an article presented in the online preprint library bioRxiv, scientists report on the ability of flowering plants to register acoustic vibrations and recognize the approach of an insect, attracting it by releasing additional amounts of nectar.
The authors used evening primrose plants (Oenothera drummondii), a relative of ivan tea, by exposing them to sounds of different frequencies and measuring the smallest vibrations of the petals. In addition, the interaction of such flowers with pollinating insects was recorded using video recording in natural conditions. Experiments have shown that plant petals tremble in different ways - depending on the frequency of acoustic exposure. But only if this frequency turned out to be close to the frequency of the sound of a flying bee, the plants reacted and after a couple of minutes they began to secrete nectar. This “behavior” should be truly beneficial, allowing both plants and pollinators not to waste nectar for the former, and time for the latter.
By repeating the experiments with flowers that had been completely emptied of nectar beforehand, the scientists found that under the influence of the sound of a pollinator flying, the plant begins to produce nectar containing, on average, 20 percent more sugars. Other acoustic frequencies did not produce this effect. The authors even suggest that the flower itself serves as the "ear" of the plant; in any case, the sound "processing" of leaves and stems did not have the same effect. Perhaps, the registration of acoustic signals is one of the secret functions of a flower, which we did not even suspect until now.