Motorists in Argentina were faced with a confronting sight as they drove towards what appeared to be a forming tornado recently – but on closer inspection, it was actually something else entirely.
Footage filmed by a person driving along Route 74 between General Madariaga and Pinamar revealed the dark tornado-like formation was actually a huge swarm of mosquitoes.
“It’s getting bigger and bigger, I’ve never seen anything like this in my life,” the person filming says, according to local media reports.
The video was shared online where it quickly went viral, attracting horrified reactions from social media users.
The bizarre scenes occurred after the Buenos Aires region of Argentina recently saw an explosion of mosquitoes after consistent heavy rains.
“Heavy rains caused flooding resulting in large pools of stagnant water where female mosquitoes lay their eggs,” researcher at the Centre for Parasitological and Vector Studies (CEPAVE), Juan Jose Garcia, told local media.
Mr Garcia said this can result in “huge numbers” of the insects being born at once, with population numbers so high they appear to “invade cities”.
Though the idea of coming face-to-face with a mosquito tornado isn’t pleasant, Mr Garcia said they pose little threat to humans.
However, he did add that they could interfere with farming activities.
He said the swarm should start to dissipate after 15 days, when many of the insects will likely die.
Last year, Australians were warned parts of the country could see a mosquito explosion due to the wet weather brought on by La Nina.
The weather event generally means above average rain for northern and eastern Australia for the second half of the year, often spreading far inland.
All that moisture can be great for farmers, watering the land. It can also make bushfires less likely.
However, mozzies love moisture too. They like nothing better than stagnant or still water, such as a pond, marsh or just a plant pot filled with rain, to lay their larvae in.
“Historically, major outbreaks of mosquito-borne disease have been associated with extensive inland flooding. This flooding is typically associated with prevailing La Nina conditions,” Dr Webb told The Conversation.
BOM records have shown that widespread flooding over summer 2010/2011 resulted in a boom in mosquito-borne diseases.