Science

Plastic-Eating Mosquitoes Could Threaten Ecosystems on Earth

Plastic-Eating Mosquitoes
Image source: Biology Letters

The world is fighting plastic waste that threatens to pollute Earth and contribute to climate change. Now scientists say plastic-eating mosquitoes are responsible for bringing waste into our ecosystems and polluting our environment.

A new study conducted at the University of Reading discovered small fragments of plastic inside flying insects that lay eggs in water, like mosquitoes. That’s how plastic waste from water is transferred from larvae to adult mosquitoes.

The team working on the study, which was published in the journal Biology Letters, discovered that larvae consumes microplastics from polluted water, and then that waste remains through the metamorphosis stage and into the non-feeding pupa. Eventually, they become plastic-eating mosquitoes.

This process is particularly dangerous for ecosystems around the world and can jeopardize major food chains. Birds and bats feed on flying insects like mosquitoes, which means the plastic may further spread to other animals, causing even greater danger.

The study’s lead author, University of Reading Professor Amanda Callaghan, said in a statement, “Much recent attention has been given to the plastics polluting our oceans, but this research reveals it is also in our skies. This is eye opening research, which has shown us for the first time that microplastics are able to navigate several life stages in flying insects, allowing them to contaminate all kinds of living creatures who would not normally be exposed to them. It is a shocking reality that plastic is contaminating almost every corner of the environment and its ecosystems.”

Plastic-eating mosquitoes consume microplastics which end up in the environment due to pollution; it can take hundreds of years for these plastics to break down in nature. Moreover, scientists find that this problem is spreading around the world in both oceans and freshwater. Plastic waste is also released into the water as remnants of many cosmetic products. After that, marine animals consume them, and the plastic continues to be transferred through the food chain to other creatures.

However, this study is the first to confirm that plastic can be transmitted at different life stages of an animal, like from larvae to adult mosquitoes, as move from the water into a terrestrial environment.

Doctoral student Rana Al-Jaibachi wanted to test this study on plastic-eating mosquitoes by feeding fluorescent plastic microbeads to mosquitoes. Using microscopes, she found that the microplastic was transferred via feeding from the larval stages, grew into  non-feeding pupa, and finally became an adult insect with microplastic inside.

Humans not exposed to risk

“The problem is they are bioaccumulating,” Callaghan told Newsweek. “So, the more animals lower down in the food chain that have plastics in them, they’ll be eaten by something else, which is eaten by something else, so there will come a point where there are quite high plastic loads.”

With more than 8 million metric tons of plastic entering the ocean each year, according to a 2015 study in the journal Science, the amount of plastics in land creatures could add up.

Callaghan also told Newsweek that plant-eating mosquitoes can’t transfer plastic into humans, unlike the diseases they transfer with their bite, like malaria. The only way plastic could be transferred to humans is if it ends up in in the salivary glands in their mouths. However, the team hasn’t found any evidence of plastic in the heads of these insects.