In the season of colorful flowers, all kinds of flower fragrance are like a pot of hodgepodge for most of our noses. However, insects have a much more sensitive sense of smell than us. They can not only detect subtle odor differences, but also find their favorite among them. For this reason, flowers have customized "fragrance road signs" for their pollinators.
The sweet fragrance of roses and roses is loved by many insects. In many cases, this kind of smell is based on aromatic linalool and benzoin aldehyde, combined with special esters (such as citronella acetate in roses). Although the modulation formulas of different plants will be different, the basic meaning of "sweet taste" is the same, which is to lure insects to "eat". For bees and butterflies who like pollen and nectar, this smell is irresistible.
But there are exceptions. Some flies are indifferent to the sweet smell and are interested in the smell of decay. Therefore, those plants that need fly pollination add amines to the flower fragrance to turn the flower fragrance into flower odor, which is used to attract the odor chaser among insects. The stinking King King flower, which lives in the jungle of Malaysia, is the representative of this kind of plant.
Some flowers are neither fragrant nor smelly, but give off the smell of grass left after mowing the lawn. Who is this for? The answer is wasps. Usually, when plants are invaded by herbivores, they will release a large number of fatty acid derivatives. These grass smelling chemicals will call carnivorous insects such as wasps and Apodemus to attack the enemy and rescue the injured plants. Other plants send fake distress signals that attract real pollinators, as is the case with flowers like burning orchids.