Turning blue is not something we tend to associate with a viral infection. And yet, this Smurf-like symptom is common among invertebrates.
Photographer Josh Coogler from Dallas, North Carolina, found a group of these brightly-colored bugs in his backyard on Wednesday afternoon. Coogler took to social media to share footage of the iridescent invertebrates.
"I've known about them for years but I found a lot of them that day," Coogler told Newsweek. "I usually only see them every once in a while but that time I found about seven in just a minute or two."
The group of viruses responsible for this unusual coloration are called invertebrate iridescent viruses and can infect a wide range of species.
"Invertebrate iridescent viruses (IIVs) infect insects and crustaceans, often those in aquatic/damp habitats or soil-dwelling species," Vera Ros, a professor of virology at Wageningen University in the Netherlands, told Newsweek. "Most infections are found in isopods, mosquitoes, beetles and lepidopteran larvae, also known as caterpillars. But other insects can be infected [too]."
Woodlice are a type of isopod, a group of crustaceans characterized by their hard, segmented exoskeletons and seven pairs of legs. The virus turns them blue because of the way it grows inside the animal's body.
"The virus replicates in the woodlouse and starts to pack into crystal-like structures made up of lots of [virus particles]," Samuel Jones, a researcher at the University of Manchester who studies the interactions between viruses and materials, told Newsweek. "These crystals refract light in a specific way to create light. This is called structural color and is seen in some insects, butterfly wings and some fruits and berries where it's not caused by a virus."
Ros said that the extent of this coloration will depend on the severity of the infection. "The blue color is seen in heavily infected individuals, and the colors range from lavender to turquoise for most host species, although green or orange has been seen in some species," she said.
The infection can be spread through a range of different interactions and will vary between different viral strains. "Cannibalism, intraspecific predation and necrophagy are effective transmission routes in some species," Ros said.
The infection can be lethal, particularly in younger individuals or those with a high viral load. In others, the infection may simply be chronic and result in reduced reproduction and longevity.
Blue woodlice can be found around the world, across Europe, Asia, North America and Australia. However, the details of its distribution are largely unknown. While studying the virus, Jones and his team launched a Citizens Science Project called Blue Woodlice to help map the location of this infection across the United Kingdom and the world.
"It reached quite a wide global audience, and anyone could go out and search for blue woodlice," he said. "The virus seems to be common in certain locations...once people found one or two in a location there seemed to be quite a few around."
It is important to note that, while these viruses are widespread among invertebrates, they do not infect human cells.
Uncommon Knowledge
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Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
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Pandora Dewan is a Senior Science Reporter at Newsweek based in London, UK. Her focus is reporting on science, health ... Read more
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