Around 300 million years ago, dragonflies were insects to evolve. According to Smithsonian Magazine, fossils of ancient dragonflies have wingspans of up to two feet, but modern versions have wingspans of only two to five inches.
Algerian biologist Rassim Khelifa, a quantitative ecology postdoctoral researcher at the Biodiversity Research Center at the University of British Columbia, said that he could see dragonfly species that he had not seen in a century. Now, he studies their diet to see if they can be used on farms as natural pesticides. Previous studies showed that artificial pesticides are the largest driver of the population decline of insects.
Dragonflies Could Potentially Replace Pesticides, Algerian Biologist Suggests
Dragonflies as Natural Pesticides in Farms
Khelifa told Forbes that reducing pesticides while also maintaining yield is a challenging part of farming. Many farmers would use artificial pesticides to control pests. Also, it needs a good understanding of the different natural or biological interventions that could work against pests without harming the crops.
He noted that dragonflies had been overlooked as a potential natural pest control compared to other insects despite being commonly used in agricultural lands and their higher position in the food chain than a range of insects. But then he pointed out that the biggest challenge in his work is catching the biggest species of dragonflies because not only do they rarely land, but they also fly very fast.
But then, by chance, he found his "Eureka moment" when he came across a rare species of damselfly that had never been seen in a century. He narrated that he was conducting genetic analyses on the feces of dragonflies to know their diet across farms that have different agricultural practices. He was in his early 20s and was studying biology at the University of Guelma in northeastern Algeria.
But aside from the potential of dragonflies as natural pesticides, other scientists have also found an inspiring, smart solution on the molecular level. Sandra Arias, a Colombian scientist, said that they are also investigating how they can use the mechanism behind dragonfly wing structure in making smart materials that use only microscopic, spiky texture in eliminating bacteria.
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Dragonflies and Other Insects in the Verge of Extinction
The alarming new assessment by the International Union for the Conservation of Nature's (IUCN) Red List of Threatened Species showed that nearly one-fifth of the dragonflies and damselflies in the world are at risk of extinction. Both insects rely on swamps, marshes, and free-flowing rivers to survive and breed.
Also, they serve as a natural predator to mosquitoes and act as prey to birds and fish, according to National Geographic. However, the destruction of their habitats due to urbanization and unsustainable agricultural practices caused their species' population decline. Now, they have a 16% risk of getting extinct, equivalent to 962 species that could completely die off.
Smithsonian Magazine reported that since the last century, 64% of the world's wetlands have disappeared, and more than a quarter of all species are threatened in Southeast Asia. Meanwhile, deforestation due to residential and commercial buildings has contributed to insect's decline in Central and South America. Likewise, pesticides, pollutants, and climate change were the biggest threats to dragonflies and damselflies in North America and Europe.
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