- Air pollution changes the scent of flowers and makes it difficult for bees to find them.
- Research shows that ground-level ozone changes the scent of flowers, and bees only recognize the smell of flowers after they are only a few meters away.
- Recent reports show that particulate matter (PM) pollutants, diesel emissions, and tropospheric ozone also impact insect pollination.
- Increasing exposure to ozone makes Erodium paularense flowers smaller, with a reduced purple color brightness. As a result, flies and butterflies have a little difficulty finding it.
Beetles have difficulty finding flowers. This metaphor really applies to the relationship between pollinating insects and various flowers. Because of pollution, many insects are forced to work harder to find flowers. For example, the Apis mellifera bee , a superior honey bee that is developed everywhere, including Indonesia.
According to scientists , bees can find flowers in several ways. One way is through smell. Initially, bees' olfactory receptors detect floral aromas called volatile organic compounds (VOC) or organic compounds that evaporate easily. This information is then stored in the insect's brain. Insects follow the scent path in the air until they land on a flower. The flowers then provide them with honey, and the bees help the plants through pollination.
But pollution disrupts this mutually beneficial relationship that has existed for 140 million years. A study conducted in 2023 by the UK Center for Ecology and Hydrology , Universities of Reading, England, found that ozone pollutant had changed the aroma of flowers. As a result, bees only recognize the smell of flowers after they are only a few meters away. In fact, honey bees in the right conditions can smell flowers from a distance of more than 100 meters.
The ozone referred to in the research is ground-level ozone which is formed when nitrogen oxide emissions from vehicles and industrial processes react with VOCs.
"Our research provides strong evidence that changes in ground-level ozone that affect flower aroma cause pollinators to have difficulty carrying out their important role in nature, which also has implications for food security," said Christian Pfrang, who collaborated on the research, as quoted by Sciendaily .
The latest report , published in January 2024, records even more impacts of pollution on insect pollination. The report was done by Laura Duque and Ingolf Steffan-Dewenter from the University of Würzburg, Würzburg, Germany. This time they focused on particulate matter (PM) pollutants, diesel emissions and tropospheric ozone, the amounts of which continue to increase from year to year.
Increasing exposure to ozone makes Erodium paularense flowers smaller, with a reduced purple color brightness. As a result, flies and butterflies have a little difficulty finding it. The smell of tobacco flowers (Nicotiana alaba) also changes when exposed to high levels of ozone. As a result, the tobacco moth (Manduca sexta) , which is responsible for pollinating this plant, does not like the changing aroma of flowers.
Pollution has been proven to make flowers less aromatic, thereby reducing the attraction of pollinating insects. Pollinators also have difficulty detecting the presence of flowers. As a result, pollinators take longer to get food.
The duration of the honey bee Apis mellifera foraging increased by 71 percent during a dust storm. This assumes the same results as concentrations of PM originating from human activities increase. Other research shows that honey bees experience stress, and their survival rate decreases when they are in a polluted environment.
Unfortunately, pollution also disrupts insects' love affairs. One of them is Drossophila which is also known as fruit fly. A number of researchers from Max Planck Germany found that ozone exposure caused sexual communication disorders in these flies.
"We already know that environmental pollutants such as ozone and nitric oxide reduce the aroma of flowers, making them less attractive to pollinators," said Markus Knaden, one of the researchers, as quoted from Phys .
Carbon double bonds are very sensitive to ozone, and almost all insect sex pheromones contain these double bonds.
"We wondered whether air pollution also affects how well female and male insects find and identify each other when mating," he continued.
When several Drosophila flies were placed in a room exposed to ozone, the attraction of males to females apparently increased. Males are not attracted to females that have mated with other males because of the pheromone trails they leave behind. Surprisingly, the increase in ozone makes males attracted to other males. How this sexual orientation changes still needs further research.
Now they want to further research the impact of ozone on other species such as bees, ants and wasps. This animal is known to use chemical compounds as a means of communication. For example, in ants and bees, can ozone pollution affect their social structure?
According to them, the study provides an additional explanation for why insect populations are declining drastically throughout the world. If chemical communication is disrupted by pollutants, it will affect the pollination process of various plants. In fact, most of the plants cultivated by humans depend heavily on insects for pollination. Thus reducing pollution drastically as well as saving food crops.