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fir0002 | via Wikimedia Commons // CC BY-NC 3.0

The Strength of Spider Web Glue Is Affected by UV Light

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fir0002 | via Wikimedia Commons // CC BY-NC 3.0

As you trick or treat today among the ubiquitous giant spiders posed in elaborate fake webs, take a moment to ponder the extraordinary talents of our real arachnid friends. Consider this, for example: Real spiders spin webs covered in an extremely strong natural glue that all but seals the fate of unfortunate insects that bumble into the trap.

Now, scientists are yielding new data about the varying degrees to which different species’ web glue can resist damage by ultraviolet radiation—information that may eventually lead to the development of new, more environmentally friendly adhesive products.

For years, researchers in biologist Brent Opell’s lab at Virginia Tech have been stalking spiders and collecting their webs in order to learn more about how the glue works. They know that spiders secrete tiny droplets containing a special protein as they spin their silken threads. The droplets become sticky once exposed to air, creating the glue-like substance.

That glue’s stickiness can be affected by a variety of conditions, including humidity and temperature. And in a new study recently published in the Journal of Experimental Biology, Virginia Tech scientists report that ultraviolet radiation also affects spider glue—some much more than others.

To test the effects of ultraviolet B (UVB) radiation, the scientists collected fresh webs made by five different species of so-called orb weaver spiders, which make classic wheel-shaped webs. They then harvested the sticky droplets from the web, and exposed them to varying intensities of UVB rays.

Some webs belonged to spider species that prefer to catch their prey in broad daylight. The others came from species that hunt at night or in forests, where webs receive little or no direct sunlight.

“We shocked some of them with UVB radiation under a light like what you might find in a tanning bed, kept some in dark, and then looked at how the drops responded after being subjected to different levels of radiation,” Sarah Stellwagen, the study’s lead author, told mental_floss.

Stellwagen and her team discovered that the glue of spiders that hunt in daylight not only resisted damage from UVB rays much better than those of the nocturnal and shade-loving forest spiders, but was slightly enhanced by it.

What exactly makes some spider web glue better able to withstand UVB rays remains a mystery, at least for now.

“It could be something happening with the protein that UVB rays actually strengthen it [in some species],” Stellwagen said. “Just like the dentist uses UV light to strengthen the bond that they fill your teeth with.”

No one has yet made an adhesive based on the spider’s glue. First, scientists need to better understand the properties and function of the protein from which the glue is created, how it varies from species to species, and how other environmental factors may affect the glue’s stickiness.

But the fact that spider glue is biodegradable, stable for long periods of time, and extremely strong make it a good candidate for biomimicry—the creation of materials inspired by biological substances and processes occurring naturally in plants or animals.

With further study, material scientists could construct new molecules that have similar abilities to resist UVB radiation. That could eliminate the need for UV-stabilizing chemicals that prevent degradation caused by light in manmade adhesives.

“It definitely has uses, and being a green product, it could replace some other products that cause pollution,” Stellwagen said.

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Lucy Stockton/National Trust Images
This Just In
The Tiny, Pretty Diamond Spider Isn't Extinct After All
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Lucy Stockton/National Trust Images

An elusive spider that was believed to be extinct in Britain has been spotted for the first time in nearly 50 years, according to The Telegraph.

Pretty little Thanatus formicinus—more commonly known as the diamond spider—is just a third of an inch long and gets its name from the thin black diamond on its hairy gray abdomen. The spider typically lives in damp areas with moss and flowering plants, like heather and purple moor grass. But since the arachnid was last spotted in England’s Ashdown Forest in 1969, conservationists assumed that it had fallen victim to habitat loss.

Turns out, the spider wasn’t extinct—it was just laying low for a few decades. While conducting an ecological survey of Clumber Park—an expanse of heath, woods, and parkland in Nottinghamshire—two volunteers with England’s National Trust conservation organization recently spotted the long-lost arachnid.

“The spider ran away from me twice, but with persistence and some luck, I caught it,” said Lucy Stockton, the National Trust volunteer who sighted the arachnid along with companion Trevor Harris.

The duo’s discovery in Clumber Park marks just the fourth time the spider had ever been recorded in the UK, and the only time it's been seen in the north of the country. “We are absolutely delighted that this pretty, little spider has been re-found, we had almost given up hope,” commented Mark Shardlow, the chief executive of Buglife, an English conservation group. “It is a testament to the crucial importance of charities like the National Trust saving and managing heathland habitats.”

[h/t The Telegraph]

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20th Century Fox Home Entertainment
The Peppa Pig Episode Kids in Australia Can't See
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20th Century Fox Home Entertainment

Kids in Australia have reason to be wary of eight-legged creatures. The continent is home to some pretty dangerous spiders, including deadly funnel-web spiders, which have strong enough fangs to bite through a toenail. Australia's spiders have claimed a new victim, though: a few episodes of the animated British show Peppa Pig.

As Slate reports, an episode of the show has been pulled from the broadcast lineup in Australia for urging kids not to be afraid of spiders. The episode, "Mister Skinnylegs," first aired in 2004, and had already been banned from public broadcasting in 2012, but it recently re-ran on Nick Jr. through the Australian cable service Foxtel. Another episode featuring the same spider character, "Spider Web," is also banned in the country.

In "Mister Skinny Legs," Peppa Pig's brother George finds a spider in the sink and becomes its friend. Peppa is scared at first, but her father tells her, "There's no need to be afraid. Spiders are very, very small, and they can't hurt you."

Arguing that Down Under, spiders can, in fact, hurt you, parents complained that the episode was inappropriate for impressionable Australian viewers. After the outcry following the August 25 re-run, Nick Jr. has agreed to pull the episode from rotation in Australia.

While Australia does have some scary spiders, the risk may be a bit overblown. In a recent study, researchers found zero deaths from spider bites in the country between 2000 and 2013. (There was one fatality in 2016, but it was the first in 37 years.) Almost 12,000 people did end up in the hospital with spider bites during those years, though. On the other hand, the same study found that more Australians were killed by horses during that time period than all of the country's venomous creatures combined. Still, it's perhaps best to avoid telling kids to make friends with black widows. Watch the episode below at your own risk.

[h/t Slate]


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