Scott Bauer, USDA via Wikimedia Commons // Public Domain
Scott Bauer, USDA via Wikimedia Commons // Public Domain

Ticks' DNA Data May Someday Help Us Control Them

Scott Bauer, USDA via Wikimedia Commons // Public Domain
Scott Bauer, USDA via Wikimedia Commons // Public Domain

When ancient military strategist Sun Tzu counseled his readers to “know thy enemy,” he was almost certainly not talking about ticks. But for many Americans, especially those with Lyme disease, ticks are the enemy. And now we know a whole lot more about them, because scientists have sequenced the tick’s genome. The results were published today in the journal Nature Communications. 

Like bedbugs, whose DNA also got a closer look recently, deer ticks (Ixodes scapularis) continue to spread across the United States. A recent survey found them in nearly half of U.S. counties—a huge increase from the last tick inventory. But it’s not just the ticks that are spreading. Where they go, disease follows: Lyme disease, yes, but also human granulocytic anaplasmosis, babesiosis, and the deadly Powassan virus.

In other words, understanding the little bloodsuckers has become pretty important to a lot of people. The tick genome project was a massive undertaking, involving 93 scientists from 46 institutions. 

"Genomic resources for the tick were desperately needed," lead author Catherine Hill said in a press release. They were also difficult to come by. The tick’s DNA would not give up its secrets easily. The tick’s genome is smaller than those of humans, but just as complex, and peppered with redundant sections that made it harder to parse.

But even these tricks were no match for an army of determined scientists. And once the genome was decoded, it revealed all kinds of useful tidbits. The researchers found proteins in the tick’s salivary glands that help transmit disease-causing bacteria to its host. 

They also found hormones that affect tick growth and sexual maturity. Researchers say that manipulating those hormones via a tick “birth-control pill” may be a viable form of tick control in the future. 

"The genome provides a foundation for a whole new era in tick research," Hill said in the press release. "Now that we've cracked the tick's code, we can begin to design strategies to control ticks, to understand how they transmit disease, and to interfere with that process."

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Michael Hutchinson
Spiders Can Fly Through the Air Using the Earth's Electric Field
A spider exhibiting ballooning behavior.
A spider exhibiting ballooning behavior.
Michael Hutchinson

Every so often, otherwise Earth-bound spiders take to the air. Ballooning spiders can travel hundreds of miles through the air (and, horrifyingly, rain down on unsuspecting towns). The common explanation for this phenomenon is that the spiders surf the wind on strands of silk, but there may be other forces at work, according to a new study spotted by The Atlantic.

In the research, published in Current Biology, University of Bristol scientists argue that Earth's atmospheric electricity allows spiders to become airborne even on windless days. To test their hypothesis, the researchers exposed spiders in the lab to electric fields similar to those naturally found in the atmosphere.

When the electric field was turned on, the spiders began to exhibit behavior associated with ballooning—they "tiptoed" on the ends of their legs, raised their abdomens, and released silk. Spiders only exhibit this behavior when ballooning. And when they did become airborne, the spiders’ altitude could be controlled by turning the electric field on and off. When the electric field was on, they rose through the air, but when it was off, they drifted downward.

This provides a potential explanation for why spiders take to the skies on certain days but not others, and how they can fly in calm, windless weather— something scientists have puzzled over since the early 19th century. (Even Darwin was flummoxed, calling it "inexplicable," The Atlantic notes.) However, the researchers note that these electric fields might not be totally necessary for ballooning—wind alone might work perfectly fine on some days, too. But understanding more about when and how spiders become airborne could help us predict when there will be large masses of arachnids flying through the skies (and hide).

[h/t The Atlantic]

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iStock
How Spiders Surf the Wind For Miles on Strands of Silk
iStock
iStock

Spiders may very well be hairy and scary, but at least they can’t fly … right? Well, that depends on your definition of flight. As The New York Times reports, new aeronautical research is shedding light on the little-understood phenomenon of “ballooning,” which lets spiders span great distances—even oceans—by riding the wind like paragliders.

Moonsung Cho, an aeronautical engineer, started researching “spider flight” after witnessing a spider being carried by the wind in Denmark. Scientists have long known that spiders sometimes use flight to evade threats or seek food and mates in other locations, but prior to this study, the physics of how it actually works remained fuzzy.

Cho and his colleagues brought crab spiders back to the laboratory and used a wind tunnel to observe their response in a controlled setting. They discovered that a spider will use its leg as an anemometer, lifting one limb to test the strength of the wind. (Their idea of perfect flying weather is a light breeze of about 7 mph.)

Then, the spider lifts up its abdomen, shoots strands of silk skyward, and lets itself be carried off into the sunset. These strands of silk are far thinner than a strand of human hair and can measure up to 6 feet long. As Live Science puts it, a strand of silk contorts when it’s caught in the wind, thus “catching air like an open parachute.” This lets spiders surf the air current, at least for a few miles.

Instances of “spider flight” have been witnessed all over the world. Residents of one Australian town reported seeing a “tunnel of webs” in the sky back in 2015. Spiders sometimes migrate en masse, and although they use the wind to move about, they can’t control where they end up. Some have even landed on islands in the middle of the ocean.

Check out this video from The New York Times to learn more ballooning.

[h/t The New York Times]

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