As Wetland Habitats Disappear, Dragonflies and Damselflies Are Threatened With Extinction

Nearly a fifth of the world's dragonflies and damselflies are at risk of extinction, according to an alarming new assessment by the International Union for the Conservation of Nature's (IUCN) Red List of Threatened Species.

The insects rely on marshes, swamps, and free-flowing rivers for breeding and survival. Likewise, dragonflies and damselflies are crucial to wetland ecosystems because they munch on mosquitos in both their nymph and adult stages and serve as prey to birds and fish, per National Geographic. But destruction of these wetland habitats is driving the species' population decline, per a statement by the IUCN. Of 6,016 damsel and dragonfly species, 16 percent are at risk of extinction, or about 962 species total, reports Holly Bancroft for the Independent.

Wetland ecosystems are being lost to urbanization and unsustainable agricultural practices. Since 1900, 64 percent of the world's wetlands have disappeared, with 35 percent of wetland habitat losses occurring after 1970, per the 2021 Global Wetland Outlook report. More than a quarter of all species are threatened in Southeast Asia because rainforest and wetland areas are cleared to make room for palm oil plantations, per the Independent. In Central and South America, deforestation for residential and commercial buildings is a significant cause for the insect's decline. In North America and Europe, the biggest threats to dragonflies and damselflies are pesticides, pollutants, and climate change, per a statement.

"Marshes and other wetlands provide us with essential services," IUCN director general Bruno Oberle said in a statement. "They store carbon, give us clean water and food, protect us from floods, as well as offer habitats for one in 10 of the world's known species." Globally, wetlands are being lost three times faster than forests, Oberle further explained in the statement. 

Soon after mating, female dragonflies will deposit eggs in rotten wood, directly into the water as a jelly-like substance, or in plant material, like plant stems, leaves. Once hatched, a nymph will spend most of their lives in this stage before crawling out of the water to turn into a dragonfly, per the British Dragonfly Society. For example, the golden-ringed dragonfly (Cordulegaster boltonii) can spend up to five years in the water before they undergo emergence and molt into adult dragonflies. As adults, some dragonflies only live for a few weeks or months before their life cycle ends.

Because dragonflies spend a good portion of their lives in water, they are sensitive indicators of the state of freshwater ecosystems and can be used as a bioindicator, Viola Clausnitzer, co-chair of the IUCN Dragonfly Specialist Group, explained in a statement. 

"To conserve these beautiful insects, it is critical that governments, agriculture, and industry consider the protection of wetland ecosystems in development projects, for example, by protecting key habitats and dedicating space to urban wetlands," Clausnitzer says.

A few colorful species on the IUCN Red List include the sombre goldenring (Cordulegaster bidentata) dragonfly, which lists as near threatened. The yellow-and-black–striped splendid cruiser (Marcomia slendens) and the purple skimmer (Libellula jesseana), with a lilac-colored body and fluorescent orange wings, are both listed as vulnerable. The orangeback Hawaiian damselfly (Megalagrion xanthomelas) and the San Francisco forktail (Ischura gemina) are both listed as endangered, and the giant sprite (Pseudagrion bicoerulans) is listed as vulnerable. 

The total number of endangered species on the Red List exceeded 40,000 for the first time on December 9. The index tracks 142,577 animal species, of which 40,084 face threats of extinction, per the Independent.

Elizabeth Gamillo | | READ MORE

Elizabeth Gamillo is a correspondent for Smithsonian and a science journalist based in Milwaukee, Wisconsin. She has written for Science magazine as their 2018 AAAS Diverse Voices in Science Journalism Intern.