Bed bugs are getting tougher 'skin,' scientists warn

Using high-tech scanning equipment, scientists in Australia have discovered that in the battle between bed bugs and humans, some of the insects wield thicker exoskeletons, making them more resistant to insecticide.

Bed bugs are a source of itchy misery and expense for those whose homes are infested, and the number of such infestations have increased in a “dramatic” way since 2000, according to a new study in the journal PLOS ONE.

Astronaut Scott Kelly Is Psyched About The Private Space Industry

NEW YORK — The man who spent a year living in space couldn’t be happier to welcome Silicon Valley to the final frontier.

“It helps NASA do more deep space exploration-type missions,” astronaut Scott Kelly told The Huffington Post on Saturday, more than a month after returning from a year at the International Space Station. “Now, rockets and spacecraft built by commercial companies pick up the mission objects of flying into a lower orbit.” 

Signaling a shift in the space business, private companies and startups are now entering a field long dominated by NASA and industrial giants like Lockheed Martin and Boeing.

Amazon CEO Jeff Bezos recently revealed new details about his secretive rocket company, Blue Origin. Over a year after suffering a deadly test crash, Virgin Group founder Richard Branson’s space company, Virgin Galactic, has unveiled its new “mothership.” Perhaps most stunningly, billionaire Elon Musk’s SpaceX nailed a historic at-sea landing last Friday after delivering inflatable bedrooms to the International Space Station, where the 52-year-old Kelly lived from March 2015 until last month.

“It was amazing,” Kelly said in a red-carpet interview at the New York premiere of “A Beautiful Planet,” a documentary featuring footage from the year he spent on the nearly 18-year-old satellite, which holds a crew of six. A trailer for the film can be seen below.

For now, the money to be made in the private space business comes from transporting cargo to space. This serves as a revenue stream as companies shaping the industry work on perfecting the reusable rocket, a critical step to making space travel cheaper. 

The next step will be to safely transport human beings from their native planet.

Last year, NASA named the first four astronauts who will fly on the first-ever U.S. commercial spaceflight. The crew — comprising NASA’s Robert Behnken, Eric Boe, Douglas Hurley and Sunita Williams — is set to travel in spacecraft built by Boeing and SpaceX. They could take off as soon as the middle of next year. 

“It’s a really exciting time,” said Samantha Cristoforetti, a fellow record-breaking astronaut from Italy who was at the “A Beautiful Planet” premiere. “The next few years will be interesting.”

Brain Study May Shed Light On How We Fall Asleep And Wake Up

When we fall asleep at night and wake up in the morning, our brain switches between opposite modes of consciousness — but scientists know surprisingly little about how these key transitions work at a neural level. 

Now, though, we may have some answers. Research published last week in the journal Nature Communications sheds light on the neurological mechanisms that allow these processes to occur successfully. It also offers a clue as to why we sometimes can’t fall asleep — or stay awake — when we want to.

Researchers from the University of Maryland School of Medicine are investigating, for the first time, the workings of a pathway that seems to play a key role in regulating the “switch” between sleep and wakefulness. 

“If you want to understand how something as complex as sleep is produced by the brain, you have to understand the molecules within the brain that create specific patterns of neuronal activity that put the brain into particular states, such as sleep or wake,” Dr. Andrea Meredith, a neuroscientist at the university and one of the study’s authors, told The Huffington Post in an email. “Our study identified a set of central molecules (or ion pathways) in the brain’s clock circuit that perform this encoding step.”

These molecules control the sleep-wake cycle by regulating the pattern of electrical activity in the suprachiasmatic nucleus, or SCN. The SCN is a brain region within the hypothalamus — a part of the brain responsible for hormone production, among other functions — and it acts as an internal clock, governing the body’s circadian rhythms. The SCN determines when we fall asleep, how long we sleep and when we wake up. 

Ion channels are proteins that conduct electrical currents in different parts of the brain. The researchers already knew from previous work that certain ion channels, known as “BK potassium channels,” were important for regulating electrical activity in the SCN. However, they believed that in human beings, the most important activity in these ion channels took place at night.

But the new findings reveal this not to be the case. In fact, they suggest that for humans, it’s what these channels do during the day that’s more important. 

“The major surprise revealed by this study was that there is a specific biophysical switch mechanism, called ‘inactivation,’ that prevents the daytime BK channels from influencing neuronal activity in the SCN,” Meredith said. “Without daytime inactivation of BK channels, the SCN doesn’t encode the circadian time signal properly, and mice don’t sleep during the day like they are supposed to.”

In an experiment on mice, Meredith and her colleagues were surprised to find they could change the pattern of neuronal activity associated with daytime into a pattern associated with nighttime — and that it was as simple as flipping this molecular switch.

Mice sleep during the day, when their BK channels are typically inhibited — the result of this inhibition is high levels of neuronal activity that leads to sleep. When a mouse’s BK channels become active at night, its neuronal activity is lowered, triggering wakefulness. Humans, of course, sleep at night and are awake during the day, but otherwise their association between neuronal activity and the sleep-wake cycle is similar.

Having a better understanding of this neuronal pathway might help us find new ways of treating certain sleep disorders like jet lag and insomnia, which involve dysfunction of the circadian clock. 

“These channels could be specifically manipulated to correct jet lag, the clock de-synchrony that results when you travel across time zones,” Meredith said. “It has also been shown that the circadian clock can influence mood disorders, and may underlie seasonal affective disorder, a type of depression linked to fewer hours of daylight in winter.”

Sleep was once something of a mystery to scientists, but more and more research is shedding light on why we need sleep and what happens in the brain while we’re at rest. 

Another study, published Monday in the journal Nature Neuroscience, shows that memories formed in one part of the brain are replayed and transferred to a different area of the brain during sleep. The findings could tell us more about the brain mechanisms involved in Alzheimer’s disease. 

“This is the first time we’ve seen coordinated replay between two areas of the brain known to be important for memory, suggesting a filing of memories from one area to another,” study author Dr. Caswell Barry, a biologist at University College London,said in a statement. “The hippocampus constantly absorbs information but it seems it can’t store everything so [it] replays the important memories for long term storage and transfers them to the entorhinal cortex, and possibly on to other areas of the brain, for safe-keeping and easy access.”

Light-Up Device Lets You 'Talk' to Fireflies

One of summer's most magical sights is an otherwise ordinary field or backyard illuminated by tiny, pulsing points of living light, as fireflies emerge at dusk. And now, a handheld gadget called the Firefly Communicator will allow people to take part in fireflies' light-coded "conversations."

With the device, which resembles the insect it was built to mimic, users can communicate with fireflies by pushing a single button to emit stored patterns of light pulses that copy actual firefly signals, issuing a "come hither" message that attracts fireflies and lets users observe them up close.

Fireflies send their coded messages using a chemical process calledbioluminescence, which takes place in a specialized structure in their abdomens. The insect controls its own "light switch," triggering when the light goes on and off by regulating the amount of oxygen introduced into its light organ.

Scientists have found that firefly species generate unique light patterns to communicate with their own kind and to attract mates. Some species also use light flashes to lure other fireflies as prey, with females imitating the coded messages of other firefly species to trick males into coming closer so they can eat them.

Inventor Joey Stein — the Firefly Communicator's creator and the owner and lead interactive designer for Genus Ideas Inc. in New York City — told Live Science that he collaborated with entomologists specializing in fireflies in order to identify known firefly communication codes for the device, and to test it in the field. He launched a Kickstarter campaign for the Firefly Communicator on March 14, and the project reached its $10,000 funding goal after only two weeks. The campaign has raised more than $14,000 to date.

Scientists find a crab party deep in the ocean

A year ago, researchers in two small submarines were exploring a seamount — an underwater, flat-topped mountain — off the Pacific coast of Panama when they noticed a dense cloud of sediment extending 4 to 10 meters above the seafloor. One of the submarines approached closer, and the scientists could soon see what was kicking up the cloud: thousands of small, red crabs that were swarming together like insects.

“The encounter was unexpected and mesmerizing,” Jesús Pineda of the Woods Hole Oceanographic Institution in Massachusetts and colleagues write in a paper published April 12 in Peer J.

The team decided to investigate further. They sent an autonomous underwater vehicle to pass over the swarm several times, capturing images and video of the crabs. At the densest points in the swarm, there were more than 70 crabs in a square meter of ocean bottom, and this occurred consistently in a water depth of 350 to 390 meters. The crabs, all 2.3 centimeters in carapace length and larger, were moving together in the same general direction. Some would jump and swim for about 10 centimeters or so before landing back in the pack.

Using one of the submarines, the researchers collected some crabs from the swarm. Back in the lab in Woods Hole, they used DNA barcoding to identify the species: Pleuroncodes planipes. This is the same species of crab that has sometimes washed up in mass stranding events on California beaches, which the team confirmed by comparing the DNA barcodes to those of crabs from a stranding event in La Jolla, Calif., in June 2015.

For reasons that scientists still don’t fully understand, seamounts are ecological hot spots where plankton get trapped and feed a wide array of fish and marine mammals higher up in the food web. Fishermen have figured out that they can take advantage of this, but scientists are just now getting into the game and exploring these sites. Because of this, less than one percent of the world’s seamounts have been checked out by researchers. That probably explains why no one had seen a crab swarm like this before on a seamount.

But this is not the first time crabs have been seen swarming. Scientists have previously documented large aggregations of king crabs, spider crabs, tanner crabs and lyre crabs on the seafloor. Such behavior may be linked to reproduction.

And then there are the red crabs of Christmas Island in the Indian Ocean, which swarm in the millions during the wet season, coming out of the forests and making a long trek to the beach for a massive mating party.

Cassini Samples, Analyzes Interstellar Dust at Saturn

he NASA/ESA Cassini spacecraft has detected the faint but distinct signature of dust coming from outside our Solar System, from the Local Interstellar Cloud — an almost empty bubble of gas and dust we are traveling through with a distinct direction and speed.

Cassini has been in orbit around Saturn since 2004, studying the giant planet, its rings and satellites. It has also sampled millions of ice-rich dust grains with its Cosmic Dust Analyser instrument.

The vast majority of the sampled microscopic grains originate from active jets that spray from the surface of Saturn’s moon Enceladus. But 36 stick out from the crowd – and scientists conclude they came from beyond our Solar System.

In the 1990s, the ESA/NASA Ulysses mission made the first in-situ discovery of interstellar dust, later confirmed by NASA’s Galileo spacecraft. The dust was traced back to the Local Interstellar Cloud.

“From that discovery, we always hoped we would be able detect these interstellar interlopers at Saturn with Cassini: we knew that if we looked in the right direction, we should find them,” said Dr. Nicolas Altobelli of the European Space Agency and lead author of the study reporting the results in the journal Science.

“And indeed, on average, we have captured a few per year, traveling at high speed and on a specific path quite different to that of the usual icy grains we collect around Saturn.”

“Interstellar dust is one of the last bastions of the unknown in space, its individual particles being only about 200 nm in size and very hard to find,” added co-author Prof. Mario Trieloff, from the University of Heidelberg.

The dust grains were speeding through at over 72 000 km/h, fast enough to avoid being trapped inside the Solar System by Saturn’s – or even the Sun’s – gravity.

Cassini analyzed the composition of the grains for the first time, showing them to be made of a very specific mixture of minerals, not ice.

They all had a surprisingly similar chemical make-up, containing major rock-forming elements like magnesium, silicon, iron and calcium in average cosmic proportions.

Conversely, more reactive elements like sulfur and carbon were found to be less abundant compared to the average.

“Cosmic dust is produced when stars die, but with the vast range of types of stars in the Universe we naturally expected to encounter a huge range of dust types over the long period of our study,” said co-author Dr. Frank Postberg, also from the University of Heidelberg.

“Surprisingly, the grains we’ve detected aren’t old, pristine and compositionally diverse like the stardust grains we find in ancient meteorites,” Prof. Trieloff said.

“They have apparently been made rather uniform through some repetitive processing in the interstellar medium.”

The scientists speculate that dust in a star-forming region could be destroyed and recondense multiple times as the shockwaves from dying stars passed through, before the resulting similar grains ended up streaming towards our Solar System.

Mothers' milk and the infant gut microbiota: An ancient symbiosis

Nursing infants' gastrointestinal tracts are enriched with specific protective microbes. Mother's milk, itself, guides the development of neonates' gut microbiota, nourishing a very specific bacterial population that, in turn, provides nourishment and protects the child. Now a team from the University of California, Davis, has identified the compound in the milk that supplies this nourishment, and has shown that it can be obtained from cow's milk. This work could result in using cow's milk to provide that compound as a prebiotic for infants. The research is published ahead of print on April 15th in Applied and Environmental Microbiology, a journal of the American Society for Microbiology.

In earlier research, these investigators, led by David A. Mills, PhD, had shown that glycoproteins from milk, which contain both protein, and molecules containing multiple sugars, called oligosaccharides, were the source of that nourishment. They also had found that the infant-associated subspecies of the bacterium, Bifidobacterium longum subsp. infantis (B. infantis), produced an enzyme that could cleave the oligosaccharides from the milk glycoproteins, and they had identified that enzyme.

For the current study, Mills, who is Professor and Shields Endowed Chair in Dairy Food Science, and his collaborators posited that these oligosaccharides were the food source for B. infantis. They then showed that the enzyme could break down glycoproteins not only from mother's milk, but from cow's milk, releasing the oligosaccharides.

"The released oligosaccharides turned out to be an incredible substrate for B. infantis' growth," said Mills. At the same time, Mills et al. showed that the oligosaccharides did not nourish adult-associated bifidobacteria.

All that suggests that getting the bioactive oligosaccharides into infant formula could improve it, said Mills. But his emphasis is on the science, he said. "The amazing thing to me is how selective these released oligosaccharides are as a substrate for growth."

Mills noted that B. infantis has many genes involved in breaking down glycoproteins in mother's milk in order to release the oligosaccharides. Mother's milk coevolved over millions of years with mammals, and with their beneficial gut microbiota that it helped to thrive. "It is the only food that co-evolved with humans to make us healthy," said Mills.

Ultrathin organic material enhances e-skin display

University of Tokyo researchers have developed an ultrathin, ultraflexible, protective layer and demonstrated its use by creating an air-stable, organic light-emitting diode (OLED) display. This technology will enable creation of electronic skin (e-skin) displays of blood oxygen level, e-skin heart rate sensors for athletes and many other applications.

Integrating electronic devices with the human body to enhance or restore body function for biomedical applications is the goal of researchers around the world. In particular, wearable electronics need to be thin and flexible to minimize impact where they attach to the body. However, most devices developed so far have required millimeter-scale thickness glass or plastic substrates with limited flexibility, while micrometer-scale thin flexible organic devices have not been stable enough to survive in air.

The research group of Professor Takao Someya and Dr. Tomoyuki Yokota at the University of Tokyo's Graduate School of Engineering has developed a high-quality protective film less than two micrometers thick that enables the production of ultrathin, ultraflexible, high performance wearable electronic displays and other devices. The group developed the protective film by alternating layers of inorganic (Silicon Oxynitrite) and organic (Parylene) material. The protective film prevented passage of oxygen and water vapor in the air, extending device lifetimes from the few hours seen in prior research to several days. In addition, the research group were able to attach transparent indium tin oxide (ITO) electrodes to an ultrathin substrate without damaging it, making the e-skin display possible.

Using the new protective layer and ITO electrodes, the research group created polymer light-emitting diodes (PLEDs) and organic photodetectors (OPDs). These were thin enough to be attached to the skin and flexible enough to distort and crumple in response to body movement. The PLEDs were just three micrometers thick and over six times more efficient than previously reported ultrathin PLEDs. This reduced heat generation and power consumption, making them particularly suitable for direct attachment to the body for medical applications such as displays for blood oxygen concentration or pulse rate. The research group also combined red and green PLEDs with a photodetector to demonstrate a blood oxygen sensor.

"The advent of mobile phones has changed the way we communicate. While these communication tools are getting smaller and smaller, they are still discrete devices that we have to carry with us," says Someya. He continues, "What would the world be like if we had displays that could adhere to our bodies and even show our emotions or level of stress or unease? In addition to not having to carry a device with us at all times, they might enhance the way we interact with those around us or add a whole new dimension to how we communicate."

Saturn spacecraft samples interstellar dust

NASA's Cassini spacecraft has detected the faint but distinct signature of dust coming from beyond our solar system. The research, led by a team of Cassini scientists primarily from Europe, is published this week in the journal Science.

But among the myriad microscopic grains collected by Cassini, a special few—just 36 grains—stand out from the crowd. Scientists conclude these specks of material came from interstellar space—the space between the stars.Cassini has been in orbit around Saturn since 2004, studying the giant planet, its rings and its moons. The spacecraft has also sampled millions of ice-rich dust grainswith its cosmic dust analyzer instrument. The vast majority of the sampled grains originate from active jets that spray from the surface of Saturn's geologically active moon Enceladus.

Alien dust in the solar system is not unanticipated. In the 1990s, the ESA/NASA Ulysses mission made the first in-situ observations of this material, which were later confirmed by NASA's Galileo spacecraft. The dust was traced back to the local interstellar cloud: a nearly empty bubble of gas and dust that our solar system is traveling through with a distinct direction and speed.

"From that discovery, we always hoped we would be able to detect these interstellar interlopers at Saturn with Cassini. We knew that if we looked in the right direction, we should find them," said Nicolas Altobelli, Cassini project scientist at ESA (European Space Agency) and lead author of the study. "Indeed, on average, we have captured a few of these dust grains per year, travelling at high speed and on a specific path quite different from that of the usual icy grains we collect around Saturn."

The tiny dust grains were speeding through the Saturn system at over 45,000 mph (72,000 kilometers per hour), fast enough to avoid being trapped inside the solar system by the gravity of the sun and its planets.

"We're thrilled Cassini could make this detection, given that our instrument was designed primarily to measure dust from within the Saturn system, as well as all the other demands on the spacecraft," said Marcia Burton, a Cassini fields and particles scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, and a co-author of the paper.

Importantly, unlike Ulysses and Galileo, Cassini was able to analyze the composition of the dust for the first time, showing it to be made of a very specific mixture of minerals, not ice. The grains all had a surprisingly similar chemical make-up, containing major rock-forming elements like magnesium, silicon, iron and calcium in average cosmic proportions. Conversely, more reactive elements like sulfur and carbon were found to be less abundant compared to their average cosmic abundance.

"Cosmic dust is produced when stars die, but with the vast range of types of stars in the universe, we naturally expected to encounter a huge range of dust types over the long period of our study," said Frank Postberg of the University of Heidelberg, a co-author of the paper and co-investigator of Cassini's dust analyzer.

Stardust grains are found in some types of meteorites, which have preserved them since the birth of our solar system. They are generally old, pristine and diverse in their composition. But surprisingly, the grains detected by Cassini aren't like that. They have apparently been made rather uniform through some repetitive processing in the interstellar medium, the researchers said.

The authors speculate on how this processing of dust might take place: Dust in a star-forming region could be destroyed and recondense multiple times as shock waves from dying stars passed through, resulting in grains like the ones Cassini observed streaming into our solar system.

"The long duration of the Cassini mission has enabled us to use it like a micrometeorite observatory, providing us privileged access to the contribution of dust from outside our solar system that could not have been obtained in any other way," said Altobelli.

No trace of Neanderthal DNA on Y chromosome of modern men

Modern men have no traces of Neanderthal DNA on their Y chromosome, the first-ever analysis of the male Neanderthal sex chromosome has revealed.

The disappearance of the Neanderthal Y chromosome may be due to genetic incompatibilities between the two species that led to miscarriages, suggests a study published today in the American Journal of Human Genetics.

The Y chromosome is passed exclusively from father to son.

Until now, all sequencing of the Neanderthal genome had been done on females because those happened to be the specimens that provided enough good-quality DNA, the study's lead author, Dr Fernando Mendez of Stanford University, said.

"Characterising the Neanderthal Y chromosome helps us to better understand the population divergence that led to Neanderthals and modern humans," he said.

"It also enables us to explore possible genetic interactions between archaic and modern [gene] variants within hybrid offspring."

It is widely known that modern non-Africans have around 2.5 to 4 per cent Neanderthal DNA in their genes, but the Y chromosome is special, Dr Mendez said.

"Either you get the whole Y chromosome, or you get nothing," he said.

Analysis compared ancient and modern Y chromosomes

Dr Mendez and his colleagues compared the Y chromosome of a 49,000 year-old Neanderthal male found in El Sidron in Spain, with the Y chromosome from two modern humans.

Their analysis supports earlier data that estimated Neanderthals and modern humans diverged from their common ancestor around 588,000 years ago.

They also found the Neanderthal Y chromosome was distinct from any Y chromosome observed in modern humans, suggesting the lineage is extinct.

The researchers then searched for evidence that would explain why the Neanderthal Y chromosome disappeared.

"The Y chromosome has a number of genes that are specific for male functions, like making sperm, so we said maybe we'd find something in one of those, but we didn't," Dr Mendez said.

These genes did contain mutations that distinguished Neanderthals from modern humans, but none would have adversely affected their function.

Chemical composition of dust from beyond the solar system analyzed

A Heidelberg-designed dust detector on the Cassini space probe -- known as the cosmic dust analyser (CDA) -- has identified several extremely rare and minuscule particles of interstellar dust from outside our solar system, and examined their chemical composition. Surprisingly it turns out that the different dust particles are very similar in composition and have collected the whole element mix of the cosmos. The experts therefore suspect that dust is continually destroyed, reformed and thereby homogenised in the "witch's cauldron" of outer space. The results of an international research team, including scientists from the Institute of Earth Sciences and the Klaus Tschira Laboratory for Cosmochemistry of Heidelberg University, are published in "Science."

"Interstellar dust is one of the last bastions of the unknown in space, its individual particles being only about 200 nanometres in size and very hard to find," explains Prof. Dr. Mario Trieloff, earth scientist from Heidelberg University. The dust is part of the interstellar material consisting of gas and helium, as well as heavy metals, and which can arise from the condensation processes of stars and planets. These particles are the raw material that were the main building blocks for Earth and other terrestrial planets.

When it comes to studying interstellar dust, science has so far depended on particles reaching our solar system. The Stardust space probe was already able to capture particles of the very weak flux crossing our solar system. "But these particles were unusually large, so the research findings are possibly not representative," Prof. Trieloff says. By contrast, the Cassini probe could identify 36 particles of interstellar dust among millions of planetary dust particles. Furthermore the CDA is in a position to analyse them on the spot with the assistance of mass spectrometry. This has enabled much more precise results than before.

Dr. Frank Postberg, on a Heisenberg grant at the Institute for Earth Science, notes that mass spectrometric measurements can now be made for the first time on "a statistically significant quantity of such dust particles." This process had only become possible through a complex series of tests conducted in Heidelberg to calibrate laboratory models of the CDA. To achieve this aim, silicate dust had to be accelerated in the laboratory to upwards of 40 km a second, which is roughly the speed of interstellar dust.

"The result of the measurements was truly amazing," Dr. Postberg reports. "The 36 particles of interstellar origin, that are very similar in their composition, contain a mix of the most important rock-forming elements -- magnesium, iron, silicon and calcium -- in average cosmic abundance. Although a dust particle has a mass of less than a trillionth of a gram, the whole element mix of the cosmos is collected there, with the exception of very volatile gases. Such particles cannot be found in our solar system." Most scientists had expected dust populations with different compositions, corresponding to the different processes of origin in atmospheres of dying stars. These differences are also found in the stellar dust of meteorites, which is highly individual in its isotope composition. "Our data tells a completely different story," he underlines.

According to the scientists, the dust has lost its individuality because it was homogenised in the cosmic "witch's cauldron" of the interstellar medium. It contains gigantic, million-degree hot bubbles of supernova explosions, whose edges arise from shock fronts expanding at hundreds of kilometres per second, explains Dr. Nicolas Altobelli, who is the first author and a scientist at the European Space Agency (ESA). There had already been a theory, he says, that interstellar dust can survive this energy-rich environment for only a few hundred million years and that very few "lucky survivors" succeed in reaching newly forming planetary systems as intact stellar dust. The latest research results now confirm that most particles are destroyed and reformed in molecular clouds, i.e. cool, dense regions of outer space. Interstellar winds bring these particles as homogenised dust into our solar system.

New species of tumbleweed is just as bad as its parents

The humble tumbleweed — that icon of the American West, blowing across the dusty, dry landscape of every old Western movie — is an immigrant.

And it isn’t a single species, but several. The first known tumbleweed species to arrive in the United States, Salsola tragus, or Russian thistle, is thought to have hitched a ride in a package of flax seed that some Russian immigrants brought with them to South Dakota in 1873. Over the years, other tumbleweed species arrived, including S. australis, which is thought to be a native of Australia or South Africa, though their paths into the country are less well known.

The species all look pretty similar, though despite the name, they don’t all tumble. They are all weeds, and ones that can pose a fire hazard during drought — a flaming ball of dry plant material that can be blown from place to place. It’s such a serious problem that scientists have even suggested importing fungi from Russia to control the plants.

So scientists have incentive to keep track of the tumbleweed invasion. In 2002, researchers reported that there was a new tumbleweed on the scene in California, S. ryanii. The new species was truly new; it combined the 36 chromosomes of S. tragus with the 18 chromosomes of S. australis to form a hybrid species with 54 chromosomes. S. ryanii was an intermediate of its two parents, with traits like fruit size and tumbling behavior falling square in the middle of the two others. And in 2008, scientists predicted that this made it likely that S. ryanii wouldn’t be as much of a problem as its parent species because it wouldn’t be as well adapted to the landscape.

It appears that isn’t the case. Shana Welles, now at the University of Arizona, and Norman Ellstrand of the University of California, Riverside surveyed tumbleweeds at 53 sites across California. In 2002, S. ryaniihad been found in just two places in the San Joaquin Valley, but in 2012, the researchers found the plant in nine. In addition, the species also showed up at six other sites, including in coastal areas near San Francisco and Ventura. Clearly, the weed is spreading, Welles and Ellstrand report March 29 in theAmerican Journal of Botany.

“It seems likely that the range of S. ryanii will continue to expand and [the species] is likely to become an important invasive species,” the team writes. It’s now another lookalike invader that can cause problems in the drought-prone West.

It’s even possible that S. ryanii could become an invasive species in other countries, the scientists say, should its seeds find a way to hitchhike across international borders, just like its great-great-great-great-great-grandparents did.