A pristine stretch of Amazon rainforest–teeming with malaria-transmitting mosquitoes? Photo by Phil P. Harris

Most people consider saving the Amazon rainforest a noble goal, but nothing comes without a cost. Cut down a rainforest, and the planet looses untold biodiversity along with ecosystem services like carbon dioxide absorption. Conserve that tract of forest, however, and risk facilitating malaria outbreaks in local communities, a recent study finds.

Nearly half of malaria deaths in the Americas occur in Brazil, and of those nearly all originate from the Amazon. Yet few conservationists consider the forest’s role in spreading that disease. Those researchers who do take malaria into account disagree on what role forest cover plays in its transmission.

Some think that living near a cleared patch of forest–which may be pockmarked with ditches that mosquitoes love to breed in–increase malaria incidence. Others find the opposite–that living near an intact forest fringe brings the highest risk for malaria. Still more find that close proximity to forests decrease malaria risk because the mosquitoes that carry the disease are kept in check through competition with mosquitoes that don’t carry the disease. Most of the studies conducted in the past only focused on small patches of land, however.

To get to the bottom of how rainforests contribute to malaria risk, two Duke University researchers collected 1.3 million positive malaria tests from a period of four-and-a-half years, and ranging over an area of 4.5 million square kilometers in Brazil. Using satellite imagery, they added information about the local environment where each of the cases occurred and also took rainfall into account, because precipitation affects mosquitoes’ breeding cycles. Using statistical models, they analyzed how malaria incidences, the environment and deforestation interacted.

Their results starkly point towards the rainforest as the main culprit for malaria outbreaks. “We find overwhelming evidence that areas with higher forest cover tend to be associated with higher malaria incidence whereas no clear pattern could be found for deforestation rates,” the authors write in the journal PLoS One. People living near forest cover had a 25-fold greater chance of catching malaria than those living near recently cleared land. Men tended to catch malaria more often the women, implying that forest related jobs and activities–traditionally carried out by men–are to blame by putting people at greater risk for catching the disease. Finally, the authors found that people living next to protected areas suffered the highest malaria incidence of all.

Extrapolating these results, the authors calculated that, if the Brazilian government avoids just 10 percent of projected deforestation in the coming years, citizens living near those spared forests will contend with a 2-fold increase in malaria by 2050. “We note that our finding directly contradicts the growing body of literature that suggests that forest conservation can decrease disease burden,” they write.

The authors of the malaria study do not propose, however, that we should mow down the Amazon in order to obliterate malaria. “One possible interpretation of our findings is that we are promoting deforestation,” they write. “This is not the case.” Instead, they argue that conservation plans should include malaria mitigation strategies. This could include building more malaria detection and treatment facilities, handing out bed nets and spraying for mosquitoes.

This interaction between deforestation and disease outbreakis just one example of the way efforts to protect the environment can cause nature and humans to come into conflict. Around the world, other researchers have discovered that conservation efforts sometimes produce negative effects for local communities. Lyme disease–once all but obliterated–reemerged with a vengeance (pdf) in the northeastern U.S. when abandoned farmland was allowed to turn back into forest. Human-wildlife conflict–including elephants tearing up crops, tigers attacking livestock, and wolves wandering into people’s backyards–often comes to a head when a once-declining or locally extinct species makes a comeback due to conservation efforts.

“We believe there are undoubtedly numerous ecosystem services from pristine environments,” the PLoS One authors conclude. “However, ecosystem disservices also exist and need to be acknowledged.”

Periodical cicadas, like the one pictured above, have missed a lot of news about insects since they last appeared. Photo via Wikimedia Commons

After 17 years underground, billions of cicadas are ready to emerge and see sunlight for the first time. They will blanket the East Coast until around mid-June, buzzing like jackhammers in harmony as they search for a mate. Since 1996, the periodical insects, which belong to a group called Brood II, have lived as nymphs two feet deep in the soil, feeding on nothing but the liquid they suck out of tree roots. Once they crawl up to the surface, they molt, mate, lay eggs and die within a month.

Scientists are still trying to determine how periodical cicadas know when to emerge. But in the last 17 years, researchers have made some other important discoveries about other insects, some of whom also enjoy swarming the United States. Here are 17 news items about the bugs’ brethren since 1996.

1. British researchers figured out how insects fly. In 1996, scientists at the University of Cambridge solved the mystery of how many winged insects can produce more lift than can be explained by aerodynamic properties. The team unleashed hawkmoths into a wind tunnel with smoke and then took high-speed photos of the insects in flight. By studying how the smoke moved around the moths’ wings, researchers were able to determine that flying insects create whirling spirals of air above the front edges of their wings, providing more lift.

2. Cuba claimed that the United States brought an insect infestation to the island. In 1997, Cuban authorities accused the U.S. of staging a biological attack the previous year by using a crop-duster to spread insects over the island. But what really happened? An American commercial airliner had flown over the country and released smoke to signal its location, an event that coincided with bug infestations on Cuba’s potato plantations.

3. A plague of crickets ravaged the Midwest. In 2001, hordes of crickets descended upon Utah, infesting more than 1.5 million acres in 18 of the state’s 29 counties. The damaged wreaked on the ironically named Beehive State’s crops totaled nearly $25 million. Michael O. Leavitt, Utah’s governor at the time, declared the infestation an emergency and sought help from the U.S. Department of Agriculture in combating the little critters.

4. Scientists uncovered an entire new order of insects. In 2002, entomologists discovered a group of inch-long wingless creatures that comprised a new order, a taxonomic rank used in the classification of organisms. The first to be identified in 88 years at that time, the order, dubbed Mantophasmatodea, consists of insects with features similar to praying mantises. The finding became the 31st known insect order.

5. A swarm of butterflies, thought to be one single species, turned out to be 10 of them. In 2004, researchers used DNA barcoding technology to study the Astraptes fulgerator butterfly, whose habitat ranges from Texas to northern Argentina. What they found was remarkable: an insect that was thought to be one species was actually 10 different species. The species’ habitats overlapped, but the butterflies never bred with its doppelganger neighbors.

6. Researchers pinpointed the world’s oldest known insect fossil. Until 2004, a 400 million-year-old set of tiny insect jaws—originally found in a block of chert along with a well-preserved and well-studied fossil springtail—lay untouched for almost a century in a drawer at the Natural History Museum in London. The rediscovery and subsequent study of the specimen meant that true insects appeared 10 million to 20 million years earlier than once thought. The researchers believe these ancient insects were capable of flight, which would mean the tiny creatures took to the skies 170 millions years ago, before flying dinosaurs.

7. Brood X invaded the East Coast. In 2004, another group of cicadas known as Brood X emerged after 17 years underground. The bugs’ motto? Strength in numbers. This class is the largest of the periodical insects, including three different species of cicada.

8. America’s bee population started to plummet. By spring of 2007, more than a quarter of the country’s 2.4 million honeybee colonies had mysteriously vanished. Something prevented the bees from returning to their hives, and scientists weren’t sure why, but they gave it a name: colony-collapse disorder. According to a recent report by the U.S. Department of Agriculture, the phenomenon continues to plague apiaries across the country, and no cause has been determined.

9. Gypsy moths destroyed thousands of trees in New Jersey. In 2007, gypsy moths ravaged more than 320,000 acres of forest in the Garden State. One of North America’s most devastating forest pests, the insect feeds on the leaves of trees, stripping branches bare. Agricultural officials said the infestation was the worst of its kind since 1990.

10. Scientists figured out how to extract DNA from preserved insect specimens. In 2009, researchers removed a barrier from the study of early insects, a practice that often left ancient specimens destroyed. In the past, too much tinkering around with tiny specimens meant that the samples often became contaminated or eventually deteriorated. The scientists soaked nearly 200-year-old preserved beetles in a special solution for 16 hours, a process that allowed them to then carefully extract DNA from the bugs without damaging them.

11. Hundreds of ancient insect species were found lodged in one chunk of amber. In 2010, a team of international researchers discovered 700 new species of prehistoric insects inside a block of 50-million-year-old amber in India. The finding signaled to scientists that the area was much more biologically diverse than previously thought.

12. The first truly amphibious insects were discovered. In 2011, a study reported that 11 species of caterpillar with the ability to live underwater indefinitely were found in freshwater streams in Hawaii. The twist? The same insects studied were land-dwellers too.

13. Scientists discovered a cockroach with more than just a spring in its step. In 2011, a new species of cockroach, for whom jumping and hopping accounts for 71 percent of movement, was found in South Africa. Saltoblattella montistabularis can cover a distance 50 times its body length with each hop. Dubbed the leaproach, the insect relies on its powerful hind legs, which are twice the length of its other limbs and make up 10 percent of its body weight, to propel it forward in high-speed bursts.

14. Japanese scientists documented radiation-induced mutations in butterflies. When a massive earthquake and tsunami severely damaged the Fukushima nuclear power plant in 2011, dangerous radioactive materials were spewed into the air and waterways. The following year, Japanese researchers said they observed dented eyes and stunted wings in local butterflies, mutations they believe were a result of radiation exposure.

15. The East Coast suffered a stink bug epidemic. In the summer of 2011, growing numbers of stink bugs prompted the Environmental Protection Agency to issue an emergency ruling that would allow farmers to use lethal insecticides. The insects had invaded crops of apples, cherries, pears and peaches from Virginia to New Jersey.

16. The world’s largest insect was discovered in New Zealand. Scientist Mark Moffett, known as Doctor Bugs, discovered the world’s largest insect, a surprisingly friendly female Weta bug, while traveling in New Zealand in 2011. The massive creature has a wingspan of seven inches and weighs three times as much as a mouse. Here’s a video of the bug eating a carrot out of Moffett’s hand.

17. A fly found in Thailand was determined to be the smallest in the world. Discovered in 2012, the fly, named Euryplatea nanaknihali, is 15 times smaller than a house fly and tinier than a grain of salt. But don’t let the miniature bugs fool you: they feed on tiny ants by burrowing into the larger insects’ head casings, eventually decapitating them.

This adult male bedbug wants to suck your blood. Photo: Armed Forces Pest Management Board

For thousands of years, humans have shared their beds with blood-sucking parasites. The ancient Greeks complained of bedbugs, as did the Romans. When the lights go off for those suffering from this parasitic infestation today, from under the mattress or behind the bedboard creeps up to 150,000 of the rice grain-sized insects (though average infestations are around 100 insects). While bedbugs are one of the few parasites that live closely with humans yet do not transmit a serious disease, they do cause nasty red rashes in some of their victims, not to mention the psychological terror of knowing that your body becomes a buffet for crawling bloodsuckers after dark. 

By the 1940s this age-old parasite was mostly eradicated from homes and hotels in the developing world. But around 1995, the bedbug tides again turned. Infestations began flaring up with a vengeance. Pest managers and scientists aren’t sure what happened, exactly, but it may have been a combination of people traveling more and thus increasing their chances of encountering bedbugs in run down motels or infested apartments; of bedbugs bolstering their resistance to common pesticides; and of people simply letting their guard down against the now unfamiliar parasites.

Large cities such as New York have particularly suffered from this resurgence. Since 2000, the New York Times has run dozens of articles documenting the ongoing plague of bedbugs, with headlines such as Even Health Dept. Isn’t Safe from Bedbugs and Bringing Your Own Plastic Seat Cover to the Movies.

As many hapless New Yorkers have found, detecting stealthy bedbugs is only the first step of what usually turns into a long, desperate eradication battle.  Most people have to combine both pesticides and non-chemical methods for purging their apartments. In addition to dousing the apartment and its contents in pesticides, this includes throwing away all furniture the bugs are living on (streetside mattresses in NYC with a “BEDBUGS!” warning scrawled across them are not an out-of-the-ordinary sight), physically removing the bodies of poisoned bugs, subjecting the home to extreme heat or cold, or even hiring a bedbug sniffing dog. Sometimes, after so many sleepless nights and days spent meticulously combing the cracks between the mattress and sheets or searching behind couch cushions, residents simply throw up their hands, move out and start their lives over.

Recognizing this ongoing problem, researchers are constantly trying to come up with new methods for quickly and efficiently killing the pests. The latest technique, described today in the Journal of the Royal Society Interface, takes a hint from mother nature and history. For years, people in Eastern Europe’s Balkan region have known that kidney bean leaves trap bedbugs, sort of like a natural fly paper. In the past, those suffering from infestations would scatter the leaves on the floor surrounding their bed, then collect the bedbug-laden greenery in the morning and destroy it. In 1943, a group of researchers studied this phenomenon and attributed it to microscopic plant hairs called trichomes that grow on the leaves’ surface to entangling bed bug legs. They wrote up their findings in “The action of bean leaves against the bedbug,” but World War II distracted from the paper and they wound up receiving little attention for their work.

Rediscovering this forgotten research gem, scientists from the University of California, Irvine, and the University of Kentucky set out to more precisely document how the beans create this natural bedbug trap and, potentially, how it could be used to improve bedbug purging efforts. “We were motivated to identify the essential features of the capture mechanics of bean leaves to guide the design and fabrication of biomimetic surfaces [or synthetic materials that mimic ones found in nature] for bed bug trapping,” they write in their paper.  

Images of bed bug legs (yellow) on bean leaf surfaces with hooked trichomes (green). Scanning electron microscope photo from The Royal Society

They used a scanning electron microscope and video to visualize how the trichomes on the leaves stop the bedbugs in their ravenous tracks. Rather than a Velcro-like entanglement as the 1943 authors had suggested, it seems that the leaves stick into the insects’ feet like giant thorns, physically impaling the pests.

Knowing this, the researchers wondered if they could improve upon the method as a way to treat bedbug infestations, because leaves themselves dry out and can’t be scaled up to larger sizes. “This physical entrapment is a source of inspiration in the development of new and sustainable [or scalable and chemical-free] methods to control the burgeoning numbers of bed bugs,” they write.

They used fresh bean leaves as a template for micro-fabricating produced surfaces that precisely mimicked the leaves. To do this, they created a negative molding of the leaves, then poured in polymers sharing a similar material composition of the living plant’s cell walls.

Fabrication of biomimetic surfaces (d and e) from bean leaves (b and c). (1–3) A negative molding material is poured onto a leaf surface, and pressure is applied. (4–6) The leaf is removed, and the negative mold is filled with the positive replica material. (7) The negative mold is removed leaving the replica. Image from The Royal Society

The team then allowed bedbugs to walk across their synthetic leaves to test their effectiveness compared to the real deal. The fabricated leaves did snag the bugs, but they didn’t hinder the insects’ movements quite as effectively as the living plants. But the researchers are not deterred by these initial results. They plan to continue working on the problem and improving their product by more precisely incorporating the mechanical properties of the living trichomes. The optimistically conclude: 

With bed bug populations skyrocketing throughout the world, and resistance to pesticides widespread, bioinspired microfabrication techniques have the potential to harness the bed bug-entrapping power of natural leaf surfaces using purely physical means.

Researchers used miniature robots to mimic how real ants maneuver networks of their own. Credit: Simon Garnier, et al

For ants, the pheromone-laden foraging trails they leave behind are like lifelines: they direct the workers toward food hubs discovered earlier and help guide them home back to their nest.

These networks of trails can stretch for hundreds of feet, quite the achievement considering many worker ants are less than half an inch in length. One type of harvester ant can lay down a set of trails (PDF) that stretch 82 feet from the entrance of its nest. The trails of a wood ant, an insect measuring just five millimeters (that’s one-fifth of an inch), reach 656 feet, each one branching out into more pathways at up to 10 spots on each trail. The leafcutter ant can build a network that spreads for almost two and a half acres.

Ant species such as these tend to take the shortest path between their colony’s nest and a food source, following branches that stray as little as possible from the direction in which they began their journey. The forks in their network of trails, known as bifurcations, are not symmetrical and don’t branch out into angles of the same size. But do ants use a sophisticated sense of geometry to trace their path, measuring the angles of the roads before picking one?

To learn more, researchers at the New Jersey Institute of Technology (NJIT) and the Research Centre on Animal Cognition in France used miniature robots to replicate the behavior of a colony of Argentine ants on the move, reported today in the journal PLOS Computational Biology. This ant species has extremely poor eyesight and darts around at high speeds, yet it can maneuver through corridor after corridor, from home to food and vice versa.

When no obstacles are around, ants prefer to walk in a straight line without deviating from their course. People are like that too: if we were walking down a street to a restaurant that’s on the same side of the road as we are, we wouldn’t cross to the opposite sidewalk unless something was blocking our way. To imbue this sense of obstacle avoidance into the robots, researchers programmed them to avoid obstacles and follow light trails, which the researchers used as a substitute for pheromone-coated paths.

An “Alice,” a tiny robot measuring two centimeters (just less than one inch), following a trail of light using two photoreceptors. Credit: Simon Garnier, et al

The 10 tiny robots in this study, called Alices, were then tasked to navigate a maze-like environment roughly 60 to 70 times their size, from a starting point representing a nest entrance to an end point signifying a food source. Two photoreceptors, mimicking ant antennae, detected beams of light. As the robots traveled through the maze, researchers introduced a wrench in the little machines’ plans—at random points in their journey, the robots were triggered to turn, a mechanism meant to further mimic ants’ meandering gaits as they creep along their paths. These random turns rotated at angles no greater than 30 degrees, as real ants are not very efficient at physically making U-turns.

In the sped-up video below, the researchers tested the Alices’ navigation skills in a complex network, charging them with choosing the shortest route between their “nest” (on the right) to a “food source (left). Varying beams of light projected onto the maze changed the robots’ movements inside the network as their photoreceptors kicked into action.

The researchers found that, without any knowledge of the geometry of the maze, the robotic ants behaved exactly as real ants do: they made small random turns, but moved in the same general direction. When they reached a fork in the road, this led the robots to choose the path that deviated least from their initial trajectory, even though they weren’t equipped to measure any angles. When they detected a light trail, they turned to follow that path.

The researchers say this means that Argentine ants may not need to use complex cognitive processes to compute the geometry of various trails. But taking the fork in the road that leads to the shortest route to food greatly increases foraging success for an entire colony. So using pheromones with an intuitive spatial knowledge of where food may be, keeps ants on the right track; as more ants follow the path to food, pheromones become more concentrated along the path, further helping to guide ants who have yet to travel. In fact, the navigation method of choosing the correct fork in the road triples the amount of food ants bring back to their nest than if they relied on pheromones alone, says lead author Simon Garnier, a biology professor at NJIT.

“If you have only the pheromones and you don’t have this trick, you’re less efficient because you’re more likely to get the ants trapped into loops,” says Garnier, who runs the institute’s Swarm Lab, which studies insect group behavior. “So they will reinforce their path around the loop, and they’ll just get stuck in this loop and turn and turn forever.”

Such navigation may also help guide ants through underground paths that connect different parts of their nests. Replicating these natural navigation tools allows researchers to better understand the inner-workings of collective animal behavior.

Caffiene, naturally present in some plant nectars, was shown to improve honeybees’ long-term memory in a new study. Image via Wikimedia Commons/Fir0002

Caffeine is likely the world’s most popular psychoactive drug. In the U.S., an estimated 90% of adults consume it daily, either in coffee, tea, soda or energy drinks.

A new study published today in Science found that the drug isn’t just popular among humans. A group of scientists from Newcastle University in the UK and elsewhere found that low doses of caffeine are present in the nectar of coffee flowers and many types of citrus plants—and that when the honeybees imbibe the drug while foraging, they demonstrate measurably improved memory for a particular floral scent afterward.

The research team, led by Geraldine Wright, measured the levels of caffeine present in the nectar of three types of coffee plants (robusta, arabica and liberica) along with four different kinds of citrus (grapefruit, lemons, pomelo and oranges). All nectars studied contained slight amounts of the drug—with the coffee nectars containing more than the citruses—and all nectars are commonly consumed by honeybees in the wild.

To see exactly what effect this caffeine has on honeybees, the scientists investigated what the drug did to bees in a lab setting. First, they trained the insects to associate a particular floral scent with a sugar and water solution: They gave the honeybees a drink of the sugar mixture if they extended their proboscis immediately after smelling the aroma; after a number of trials, all the bees were conditioned to perform the action upon being exposed to the scent. For some bees, though, the researchers had introduced varying levels of caffeine into their sugar solution.

When the bees’ memory was tested 24 hours later—by checking if they still responded to the scent by immediately extending their proboscis—those that had caffeine in their solution demonstrated notably better memory for the scent. They were three times more likely to perform the action, and even after a full 72 hours, they were still twice as likely to remember the aroma.

A honeybee drinks nectar from a coffee flower. Image via Geraldine Wright

The findings shed light on what had long been a caffeine mystery. The drug, which is bitter when tasted in isolation, has conventionally been thought of as a defense mechanism for plants, reducing the chance that they’ll be eaten by herbivores.

In this context, botanists had long wondered why bitter caffeine is present in low doses in nectar. The sweet liquid is produced to attract bees, insects and other animals that serve as pollinators, spreading pollen between individual plants of the same species to aid in reproduction—so why would a bitter defense mechanism be included?

The levels of caffeine in the nectar of all the plants studied, it turns out, are too low to taste bitter to the bees, but just high enough to provide the memory boost. This happy medium could provide a benefit for both the bees and the plants.

“Remembering floral traits is difficult for bees to perform at a fast pace as they fly from flower to flower,” Wright, the lead author, said in a press statement. “We have found that caffeine helps the bee remember where the flowers are.” As a result, the drug gives bees the ability to more quickly find flowers that provide valuable nectar—and plants are provided with more frequent pollination from the insects.

The researchers hope that their findings will do more than let coffee drinkers know they share something in common with honeybees. In an era when crashing populations of honeybees and other pollinators are getting scientists concerned about the yields of dozens of pollinated crops and wild plant biodiversity, a better understanding of the bee foraging and pollination process could be crucial for finding a solution.

Dead locusts litter Israel’s Negev desert after being sprayed with pesticide on Wednesday. Photo: Rachel Nuwer

Locusts have plagued farmers for millennia. According to the Book of Exodus, around 1400 B.C. the Egyptians experienced an exceptionally unfortunate encounter with these ravenous pests when they struck as the eighth Biblical plague. As Exodus describes, “They covered the face of the whole land, so that the land was darkened, and they ate all the plants in the land and all the fruit of the trees that the hail had left. Not a green thing remained, neither tree nor plant of the field, through all the land of Egypt.”

Locusts attacks still occur today, as farmers in Sudan and Egypt well know. Now, farmers in Israel can also join this unfortunate group. Earlier today, a swarm of locusts arrived in Israel from Egypt, just in time for the Jewish Passover holiday which commemorates Jews’ escape from Egyptian slavery following the ten Biblical plagues. “The correlation with the Bible is interesting in terms of timing, since the eighth plague happened sometime before the Exodus,” said Hendrik Bruins, a researcher in the Department of Man in the Desert at Ben-Gurion University of the Negev in Israel. “Now we need to wait for the plague of darkness,” he joked.

With the help of the Lord, Moses delivers a plague of locusts upon the Egyptians, seen in the photo of a Bible page above. Photo via New York Public Library, Renaissance and medieval manuscripts collection

While the timing is uncanny, researchers point out that–at least in this case–locust plagues are a normal ecological phenomenon rather than a form of divine punishment. “Hate to break it to you, but I don’t think there’s any religious significance at all to insects in the desert, even a lot of them, and even if it seems reminiscent of a certain Biblically described incident,” said Jeremy Benstein, deputy director of the Heschel Center for Sustainability in Tel Aviv.

In this region of the world, locusts swarm every 10 to 15 years. No one knows why they stick to that particular cycle, and predicting the phenomena remains challenging for researchers. In this case, an unusually rainy winter led to excessive vegetation, supporting a boom in locust populations along the Egyptian-Sudanese border. As in past swarms, once the insect population devours all of the local vegetation, the hungry herbivores take flight in search of new feeding grounds. Locusts–which is just a term for the 10 to 15 species of grasshoppers that swarm–can travel over 90 miles in a single day, carried by the wind. In the plagues of 1987 and 1988 (PDF)–a notoriously bad period for locusts–some of the befuddled insects even managed to wash up on Caribbean shores after an epic flight from West Africa.

When grasshoppers switch from a sedentary, solo lifestyle to a swarming lifestyle, they undergo a series of physical, behavioral and neurological changes. According to Amir Ayali, chair of the Department of Zoology at Tel Aviv University, this shift is one of the most extreme cases of behavioral plasticity found in nature. Before swarming, locusts morph from their normal tan or green coloring to a bright black, yellow or red exoskeleton. Females begin laying eggs in unison  which then hatch in synch and fuel the swarm. In this way, a collection of 1 million insects can increase by orders of magnitude to 1 billion in a matter of months.

From there, they take flight, though the exact trigger remains unknown. Labs in Israel and beyond are working on understanding the mathematics of locust swarming and the neurological shifts behind the behaviors that make swarming possible. ”If we could identify some key factors that are responsible for this change, we could maybe find an antidote or something that could prevent the factors that transform innocent grasshoppers from Mr. Hyde to Dr. Jekyll,” Ayali said. “We’re revealing the secrets one by one, but there’s still so much more to find out.”

A swarm of locusts will consume any green vegetation in its path–even toxic plants–and can decimate a farmer’s field almost as soon as it descends. In one day, the mass of insects can munch its way through the equivalent amount of food as 15 million people consume in the same time period, with billions of insects covering an area up to the size of Cairo, Africa’s largest city. As such, at their worst locust swarms can impact some 20 percent of the planet’s human population through both direct and indirect damages they cause. In North Africa, the last so-called mega-swarm invaded in 2004, while this current swarm consists of a measly 30 to 120 million insects. 

Estimating the costs exacted by locusts swarms remains a challenge. While locust swarms reportedly cause more monetary damage than any other pest, it’s hard to put an exact figure on the problem. Totaling the true crost depends on the size of the swarm and where the winds carry it. To be as accurate as possible, costs of pesticides, food provided to local populations in lieu of wrecked crops, monitoring costs and other indirect effects must be taken into account. No one has yet estimated the cost of this current swarm, though the United Nation’s Food and Agriculture Organization (FAO) allots $10 million per year solely to maintain and expand current monitoring operations.

Locusts covering a bush during the 2004 swarm near the Red Sea cost in Israel. Photo: Amir Ayali

This morning, the Israeli Ministry of Agriculture sprayed pesticides on an area of around 1,000 hectares near the Egyptian border. To quell a plague of locusts, pest managers have to hit the insects while they’re still settled on the ground for the night and before they take flight at dawn. So far, pesticide spraying is the only option for defeating the bugs, but this exacts environmental tolls. Other invertebrates, some of them beneficial, will also shrivel under the pesticide’s deadly effects, and there’s a chance that birds and other insectivores may eat the poisoned insect corpses and become ill themselves. Researchers are working on ways to develop fungus or viruses that specifically attack locusts, but many of those efforts are still in initial investigative stages. However, the company Green Muscle developed a commercially available fungus that affects only locusts.

Even better, however, would be a way to stop a swarm from taking flight from the very beginning. But this requires constant monitoring of locust-prone areas in remote corners of the desert, which is not always possible. And since the insects typically originate from Egypt or Sudan, politics sometimes get in the way of quashing the swarm before it takes flight. “We really want to find them before they swarm, as wingless nymphs on the ground,” Ayali said. “Once you miss that window, your chances of combating them are poor and you’re obliged to spray around like crazy and hope you catch them on the ground.”

In this case, Egypt and Israel reportedly did not manage to coordinate locust-fighting efforts to the best of their abilities. “If you ask me, this is a trans-boundary story,” said Alon Tal, a professor of public policy at Ben-Gurion University. “This is not a significant enemy–with an arial approach you can nip locusts in the bud–but the Egyptian government didn’t take advantage of the fact that they have quite a sophisticated air force and scientific community just to the north.”

Ayali agrees that the situation could have been handled better. He also sees locusts as a chance to foster regional collaboration. Birders and ornithologists from Israel, Jordan and Palestine often cooperate in monitoring migratory avian species, for example, so theoretically locusts could likewise foster efforts. “Maybe scientists should work to bridge the gaps in the region,” Ayali said. “We could take the chance of this little locust plague and together make sure we’re better prepared for the next.”

For now, the Israelis have smote the swarm, but Keith Cressman, a senior locust forecasting office at the FAO’s office in Rome warns that there is still a moderate risk that a few more small populations of young adults may be hiding out in the desert. This means new swarms could potentially form later this week in northeast Egypt and Israel’s Negev region. His organization warned Israel, Egypt and Jordan this morning of the threat, and Jordan mobilized its own locust team, just in case.

For those who do come across the insects (but only the non-pesticide covered ones!), Israeli chefs suggest trying them out for taste. Locusts, it turns out, are the only insects that are kosher to eat. According to the news organization Haaretz, they taste like “tiny chicken wings,” though they make an equally mean stew. “You could actually run out very early before they started spraying and collect your breakfast,” Ayali said. “I’m told they’re very tasty fried in a skillet, but I’ve never tried them myself.”

A swarm of locusts descends upon Israel. Photo by Amir Ayali

Sign up for our free newsletter to receive the best stories from Smithsonian.com each week.

Wild bees, such as this Andrena bee visiting highbush blueberry flowers, provide crucial pollination services to crops across the globe. Photo by Daniel Cariveau

Insect pollination is crucial for the healthy development of our favorite foods, from apples and avocados to cucumbers and onions. Of the 100 crop species that provide 90 percent of the global population’s food, nearly three-quarters rely on pollination by bees. The rest need beetles, flies, butterflies, birds and bats to act as pollinators. It’s a mutually beneficial system—the flowers of most crops require pollen from another plant of the same crop to produce seeds or fruits, and bees and other critters transfer pollen from one plant to the next as they drink a flower’s nectar.

The agriculture industry relies on both wild pollinators and human-managed ones like honeybees, kept and cared for in hives across the country. Concern over the latter’s gradual decline has grown in recent times, but new research shows it might be the wild pollinators we should be worrying about.

In a study of 600 fields of 41 major crops (fruits, grains and nuts) on six continents, published today in the journal Science, researchers found that wild insects pollinate these crops more effectively than honeybees that are in the care of humans. In fact, compared to bees living in apiaries, wild pollinators lead to twice as much of what’s called “fruit set”—the amount of flowers that develop into mature fruits or seeds.

Pollination is essential for the production of fruits like cherries, cranberries and blueberries. Blueberries, along with tomatoes, especially depend on buzz pollination, a process by which bees vibrate their flight muscles rapidly to unleash a visible cloud of pollen into a flower. Honeybees aren’t capable of this kind of pollination, says lead study author Lucas Garibaldi, a professor at the National University of Río Negro in Argentina. Of all pollinator-dependent crops, approximately 8 percent require buzz pollination, he says.

Pollination, then, is central to ensuring our both our food staples and our varied diet.“These ecosystem services are free, but they’re important for our survival,” Garibaldi adds. “They need to be promoted and maintained if we want to continue living on this planet.”

Another new study found that wild bee population, as well as the number of different species of the insects, has plummeted over the last 120 years. Researchers used observations of interactions between plants and their pollinators in Illinois collected at three points in time: in the late 1800s, the 1970s and the first decade of this century. Of the 109 bee species seen visiting 26 woodland plants in the 19th century, only 54 remained by 2010. Rising temperatures caused mismatches in peak bee activity, measured by visits to different plants, and flowering times, a break in the delicate balance of insect-plant relationship.

Less diversity in the wild bee population meant fewer interactions between flowers, a change that in the agricultural world could result in smaller crop yields, says lead author Laura Burkle, an ecology professor at Montana State University. This throws off global agriculture production and speeds up land conversion to compensate for the loss.

“Things have changed for the worst,” Burkle says. “There’s an incredible amount of robustness within these interaction networks of species that allow them to persist in the face of really strong environmental changes, both in temperature and land-use change.” Unfortunately, these pollinators are “getting punched from a variety of sides,” she adds.

Can honeybees substitute for our disappearing wild pollinators? Garibaldi and colleagues found that these insects couldn’t fully replace the contributions of diverse populations of pollinators for a wide range of crops on farmlands on every continent. Flooding farmland with human-managed honeybees only supplemented pollination by wild insects, even for crops such as almonds, whose orchards are stocked routinely with bees.

Human-managed hives stocked with bees, ready to aid in pollination at an almond grove. Photo by Daniel Cariveau

Several culprits are behind the continuing decline of these wild pollinators. The insects usually live in forests and grasslands, and continuing conversion of such natural habitats into farmland results in shrinking numbers and types of wild pollinators, meaning fewer flowers receive the pollen necessary for reproduction. 

Last year, many plants in the eastern U.S. flowered a month earlier than any other time in the last 161 years, a result of such unusually warm weather. Burkle says bee development doesn’t always catch up to changing flowering times in plants, which leads to more mismatches in interaction and decreased pollination services. Another study in the same year found that elevated levels of carbon dioxide, combined with the use of nitrogen-infused fertilizer, altered some plants’ lifetime development. The toxic pairing led them to produce flowers with nectar more attractive to bumblebees than usual, but caused the plants to die sooner.

The waning insect population has already taken a measurable toll on crop production, including on one very near and dear to our hearts: coffee. A 2004 study of coffee pollination in Costa Rica found that when numbers of human-introduced honeybees shrunk in a given forest area, diverse pollinators native to the area, such as stingless bees known as meliponines native to the area, helped compensate for the loss. But these insects couldn’t survive at the edges of the forest like honeybees could, so the production of coffee, a crop highly dependent on pollination, eventually plummeted.

“This study supports the theoretical prediction that having many different species, which each respond to the environment in slightly different ways, is like having a stock portfolio from many different companies, rather than investing all your money in a single company’s stock,” explains Jason Tylianakis, a terrestrial ecology professor at the University of Canterbury in New Zealand. Tylianakis discussed the implications of Science’s two new studies in a paper also published today. “We should expect this kind of ‘insurance effect’ to become less common as more native pollinators go extinct.”

Given the mounting evidence, Tylianakis writes in an email that concerns about a global pollination crisis are not overstated. A changing climate, the rapid spread of farmland and a reliance on pesticides means diverse, wild pollinators will continue to face challenges as this century unfolds. If pollinators are dying out worldwide—and if pace of this die out continues with the variety of species getting cut in half each century, leaving behind less effective substitutes—food production as we know it could start to crumble.

“The bottom line is that we need biodiversity for our survival, and we can’t simply replace the services provided by nature with a few hand-picked species like the honeybee,” he says.

A male human head louse. Photo by Flickr user Gilles San Martin

Parasites have been around for more than 270 million years. Around 25 million years ago, lice joined the blood-sucking party and invaded the hair of ancient primates. When the first members of Homo arrived on the scene around 2.5 million years ago, lice took advantage of the new great ape on the block for better satisfying its digestive needs. As a new genetic analysis published today in PLoS One shows, mining these parasites’ genomes can lend clues for understanding the migration patterns of these early humans.

The human louse, Pediculus humanus, is a single species yet members fall into two distinct camps: head and clothing lice–the invention of clothing likely put this divide into motion. Hundreds of millions of head lice infestations occur each year around the world, most of them plaguing school-aged children. Each year in the United States alone, lice invade the braids and ponytails of an esimtated 6 to 12 million kids between the ages of 3 to 11. Clothing lice, on the other hand, usually infect the homeless or people confined to refugee camps. Clothing lice–also referred to as body lice–are less prevalent but potentially more serious because they can serve as vectors for diseases such as typhus, trench fever and relapsing fever.

Researchers have studied the genetic diversity of head and clothing lice in the past, but scientists from the Florida Museum of Natural History at the University of Florida decided to tap even deeper into the parasites’ genome, identifing new sequences of DNA that could be used as targets for tracking lice evolution through time and space. From these efforts, they found 15 new molecular markers, called microsatellite loci, which could help uncover the genetic structure and breeding history behind different lice populations–and potentially their corresponding humans of choice.

Using those genetic signals, they analyzed the genotypes of 93 human lice taken for 11 different sites around the globe, including North America, Cambodia, Norway, Honduras, the UK and Nepal, among others. They collected lice from homeless shelters, orphanages and lice eradication facilities.

Inbreeding, it turned out, is common in human lice around the world. Lice in New York City shared the most genetic similarities, pointing to the highest levels on inbreeding from the study samples. Clothing lice tended to have more diversity than head lice, perhaps due to an inadvertent bottlenecking of the head lice population due to high levels of insecticides those parasites are regularly exposed to. As a result of repeated run-ins with anti-lice shampoos and sprays, only the heartiest pests would survive, restraining the overall diversity of the population. Insecticide resistance is a common problem in head lice, but less of an issue with clothing lice. The authors identified one possible gene that may be responsible for much of the head louse’s drug resistance, though further studies will be needed to confirm that hunch. 

The researchers also analyzed lice diversity to see how it relates to human migration. They found four distinct genetic clusters of lice: in clothing lice from Canada, in head lice from North America and Europe, in head lice from Honduras and in all Asian lice.

Here’s the authors present a map of lice genetic diversity. The colored circles indicate sampling sites, with the different colors referring to the major genetic clusters the researchers identified. The grey flowing arrows indicate proposed migrations of modern humans throughout history, and the colored arrows represent the hypothetical co-migration of humans and lice.

Photo from Ascunce et al., PLoS One

How this geographic structure reflects human migration, they write, will require more sampling. For now, they can only speculate about the implications:

Although preliminary, our study suggests that the Central America-Asian cluster is mirroring the (human host) colonization of the New World if Central American lice were of Native American origin and Asia was the source population for the first people of the Americas as has been suggested. The USA head louse population might be of European decent, explaining its clustering with lice from Europe. Within the New World, the major difference between USA and Honduras may reflect the history of the two major human settlements of the New World: the first peopling of America and the European colonization after Columbus.

Eventually, genetic markers in lice could help us understand interactions between archaic hominids and our modern human ancestors, perhaps answering questions such as whether or not Homo sapiens met with ancient relatives in Asia or Africa besides Homo neanderthalensis. Several kinds of louse haplotypes, or groups of DNA sequences that are transmitted together, exist. The first type originated in Africa, where its genetic signature is strongest. A second type turns up in the New World, Europe and Australia, but not in Africa, suggesting that it may have evolved first in a different Homo species whose base was in Eurasia rather than Africa. If true, then genetic analysis may give us a time period for when humans and other Homo groups for came into contact. And if they interacted close enough to exchange lice, perhaps they even mated, the researchers speculate.

So not only can the genetic structure of parasite populations help us predict how infections spread and where humans migrated, it may give insight into the sex-lives of our most ancient ancestors.

A new study indicates that mosquitoes can become habituated to the smell of DEET over time, reducing its effectiveness as a repellent. Image via CDC

If you’re someone that’s naturally irresistible to mosquitoes, a new finding published today in PLOS ONE could make for a rude awakening. A group of researchers from the London School of Hygiene and Tropical Medicine discovered that three hours after an exposure to DEET, many Aedes aegypti mosquitoes were immune to the chemical, ignoring its typically noxious smell and attempting to land on irresistible human skin.

Normally, DEET—short for N,N-Diethyl-meta-toluamide, which is the active ingredient in most insect repellents on the market—works because mosquitoes seem to find the chemical’s smell unpleasant and actively avoid landing on surfaces where it has been applied. But in this study, led by Nina Stanczyk, the researchers found mosquito behavior that runs contrary to scientists’ previous understanding of how the insects interact with the chemical.

DEET is used in the majority of insect repellents on the market. Image via Flickr user Spokenhope

Initially, the researchers split a number of Aedes aegypti mosquitoes (a common species found on all continents, including North America) into two groups, each in a metal mesh cage. Then they had volunteers hold their arms about an inch over each cage, with one treated with a 20-percent DEET solution and another that had no repellent (a control arm).

Three hours later, they repeated the experiment, and counted exactly how many mosquitoes overcame the DEET and attempted to get through the metal mesh to reach the arms. They found that about half of the mosquitoes who’d been initially exposed to DEET on their first go-round seemed immune to the chemical during the second trial and tried to reach the DEET-covered arm, compared to the 10-20 percent that had attempted to do so during their first trial. This number was still less than the proportion of mosquitoes trying to reach the plain arm (70-80 percent).

Further proof the development of DEET immunity, though, lies in a third group of mosquitoes, who were exposed to a control arm first and a DEET arm second. Because they hadn’t had the chance to become habituated to the chemical, a much lower amount of them (less than 10 percent) tried to reach the DEET-covered arm.

To ensure that some sort of interaction between chemicals in human skin and DEET wasn’t responsible, the researchers also replicated the experiment with a heating device—to which mosquitoes are naturally attracted—that was also covered in DEET. The results were similar, indicating that the insects were somehow becoming habituated to DEET itself, regardless of the surface it was covering.

So why did the mosquitoes, as a whole, overcome their dislike of DEET? Previous studies by this group and others have found particular mosquitoes with a genetic mutation that made them innately immune to DEET, but they say that this case is different, because they didn’t demonstrate this ability from the start.

They suspect, instead, that the insects’ antennae became less chemically sensitive to DEET over time, as evidenced by electroantennography on the mosquitoes’ odor receptors after each of the tests—a phenomenon not unlike a person getting used to the smell of, say, the ocean or a manufacturing plant near his or her house.

Of course, this sort of aromatic habituation is significantly less convenient, because DEET-based repellents are relied upon not just to help us avoid irritating bites but also to stop the spread of mosquito-borne diseases like malaria and dengue. But the researchers don’t recommend dropping DEET entirely, for a few reasons.

For one, mosquitoes live as adults for only a few days at most, and the habituation likely isn’t passed along to offspring, so the odds that a particular mosquito you come across has already been exposed to DEET is pretty low. Additionally, even if it has, not all of the individual mosquitoes in the trial became used to the DEET, so it should still be somewhat effective as a repellent.

Most important, though, is the fact that we still haven’t developed any other repellent that is as consistently potent as DEET—so for now, they say, people living in areas with high risks of mosquito-borne illnesses have little other choice than to keep using it.

Footage from Brazil’s “spider rain.” Photo: TV45000

The Northeast may be prone to blizzards this time of year, but in Brazil it’s raining spiders. In a video that’s covered the Internet like an immense web, a local photographer captures images of thousands of spiders shimmying up and down silk threads attached to telephone pole wires. The footage gives the distinct impression of a shower–or perhaps light snow–of spiders sprinkling down on the shocked residents below.

Erick Reis, a 20-year-old web designer in Santo Antonio da Platina, a town about 250 miles west of Sao Paulo, captured the striking video that has since accumulated more than 2 million YouTube views over the course of the week.  “I was shooting an engagement party for some friends of mine and I saw the spiders when I was leaving, now in the late afternoon,” he explained to TV450000, which posted the video. “I’ve never seen anything like it before.”

According to biologist Marta Fischer of the Pontifical Catholic University of Parana, however, the phenomenon is not so strange. ”This type of spider is known to be quite social,” she said. “They are usually in trees during the day and in the late afternoon and early evening construct sort of giant sheets of webs, in order to trap insects.”

Scientists have described around 40,000 species of spiders around the world, but only a handful of them are social. These 23 species are scattered around the world and sometimes swarm, like ants or bees. Females often outnumber males 10 to 1 in colonies that can exceed 50,000 individuals.

Around Sao Paulo and its neighboring cities, she said, it’s not an unusual site to see a sky speckled by spiders. The species, Anelosimus eximius, can be found from Panama to Argentina and lives in colonies sometimes comprised of thousands of individuals. Each spider is around the size of a pencil eraser. As Examiner reports, the species’ webs can stretch from the ground up to tree canopies or human constructions 65 feet high.

If strong winds come along, the web may detach from its anchors, carrying the spiders and their ruined home to new sites where they appear to “rain down.” Catching rides on the wind–en mass–was likely what happened in Santo Antonio da Platina. While the humans gawked below, the flustered spiders were simply trying to pull themselves together after an unexpected journey from some forest or park.

Before North American readers breathe a sigh of relief that this isn’t happening a bit closer to home, however, it’s worth noting that similar colonies live in Texas. In Lake Tawakoni State Park, just east of Dallas, Guatemalan long-jawed spiders construct enormous webs covering up to 600 foot stretches. The spiders build the huge webs in less than two weeks. Researchers think the spiders achieve such sudden engineering feats thanks to their “remarkable reproductive capabilities and ability to disperse by ballooning,” according to A Field Guide of Scorpions and Spiders of Texas.

So far, Dallas residents haven’t reported massive sheets of webs and their arachnid residents “ballooning” into backyards. But, as witnessed by residents of Santo Antonio da Platina,  stranger things have happened. 

A cockroach diligently cleans his antenna. Photo by Ayako Wada-Katsumata

When encountering a two-inch American cockroach, most people quickly skedaddle the other way or raise a foot to stomp the little creeper out of existence. For those curious few who stick around to quietly observe the roach, however, the insect will inevitably fall into a certain diligent, repetitive motion. First, it reaches its spiny little roach feet up towards its head, then grips the base of one of its antennae and finally, as if it were spinning yarn at triple speed, threads the length of its antennae through its furiously working mouthparts.

Insects such as cockroaches, house flies and carpenter ants often engage in such antennae-grooming behavior. Like many animals, scientists know that insects frequently clean themselves, but few researchers have investigated just why bugs bother. Antennae serve not only to feel out the environment but also to sense odors, so researchers have long suspected that grooming keeps the antennae in top shape. But what, specifically, are they scrubbing from their bodies? Do roaches self-clean to remove bacteria or bits of gunk from their last meal?

To figure out just why roaches groom, lead author Katalin Böröczky and colleagues from North Carolina State University along with researchers from the Russian Academy of Sciences observed antennae-cleaning behaviors in a couple dozen adult male American cockroaches, describing their experiment today in Proceedings of the National Academy of Sciences. The researchers used an array of methods to restrain the roaches from self-grooming so that they could compare groomed and ungroomed antennae. In some cases, the scientists used a small plastic clip to tether one antenna at the base of the roaches’ heads. The frustrated insects repeatedly attempted to grab hold of their lassoed antenna but could not get a grip on it in order to clean it. Some roaches also had their mouthparts glued together while others were kept in a box too small to allow for self-grooming.

Here, you can see one of the roaches stymied by the plastic antennae blockers:

Over a period of 24 hours, the tethered antenna began to appear shinier than the other non-tethered one. Examining the shiny antenna with a scanning electron microscope revealed an unidentified substance blocking the roaches’ sensory pores and coating their antennae. The unclean antennae built up three to four times more of the stuff than the clean ones over the day.

To figure out what the unknown build-up was, the researchers took samples of it and analyzed it with gas chromatography, a technique that separates different components of a chemical compound. They found that the natural secretions that the cockroach gives off accounted for most of the substance–mostly fatty molecules that help regulate water loss in insects. Despite the seemingly sterile environment, other external contaminants were stuck on the antennae as well, including stearic acid from surfaces in the roaches’ container and geranyl acetate from the air.

The researchers guessed that this build up might impair the roaches’ ability to sniff out olfactory signals with their antennae. To test this hypothesis, they exposed roaches with groomed and ungroomed antennae to sex pheromones and other odors. Just as they suspected, roaches with clean antennae were more receptive to the odors around them than those with unclean ones. “We conclude that the disruption of grooming interferes with general olfaction,” the authors write in their paper.

Finally, to see if these findings extended to other insects, the researchers repeated their experiment in flies, ants and German cockroaches, all of which exhibited the same build up and loss of antennae function when prevented from self-grooming. They conclude that “our observations with four phylogenetically diverse species indicate that this hitherto unknown role for grooming is common to a wide diversity of insects.”

Just as humans scrub off to remove dead skin cells, sweat and dirt from the day, insects busy themselves to keep clean. While we may share this commonality with earth’s most abundant group of species, however, it may not be quite enough to inspire empathy for the next cockroach that finds its way into a closet or kitchen drawer.

Using new technology, scientists can study how infestations by insects like the western spruce budworm play a role in climate change. Photo by Paul Williams

It’s become a destructive cycle in the western U.S.: Warmer temperatures and drought conditions prolong the life cycle of mountain pine beetles, allowing them to prey on the pine, spruce and fir trees that blanket the mountains. The trees turn reddish-brown before dying off–a phenomenon the National Park Service deemed “an epidemic stretching from Canada to Mexico.” There’s widespread concern that such tree mortality creates an excellent fuel source for wildfires.

Until recently, scientists were left to survey the damage from the ground, with little ability to understand the causes and processes. But now new technology is enabling them to use satellite imagery to identify the sources of small, ecosystem-altering events–some of which, for example beetle outbreaks, are related to climate change drivers. A computer program called LandTrendr, developed by Boston University Earth and Environment professor Robert Kennedy, allows scientists to combine data they collect on the ground with satellite imagery from the U.S. Geological Survey (USGS) and NASA to get a better understanding of environmental disturbances.

Since 1972, NASA and the USGS have deployed satellites that snap specialized digital photographs of Earth’s landscapes. They’re able to capture details that exist in wavelengths invisible to the human eye, including those slightly longer than visible light called the near infrared. Healthy plants reflect energy in the near infrared, and by scanning the imagery, scientists can detect disruptions in Earth’s landscapes.

In the past, these images were prohibitively expensive, limiting scientists’ access. “We’d look at an image from 2000 and one from 2005 and ask, ‘What’s changed?’” Kennedy explained. “If you’re only looking at two images, it’s very difficult to track slowly evolving changes. You can tell something’s changed, but you don’t know how long it’s taken.”

When the USGS began providing these images for free in 2008, it was a turning point for Earth scientists. They now had access to thousands of shots of any given geographic region–images that Kennedy’s LandTrendr tool utilizes. “By looking at all the images, you can watch [changes] unfold. You have more confidence that you’re actually seeing trends,” he said. This is particularly useful for understanding climate change and land use change, which are “all about process,” according to Kennedy.

Kennedy is currently using LandTrendr technology to look at the net carbon exchange of forests; among other things, his work analyzes the amount of carbon lost in forests due to fire, clear cuts, partial cuts and urbanization. Studies of climate change in the Arctic and in transition zones between ecosystems are also utilizing LandTrendr. But in the Pacific Northwest, Garrett Meigs, a forestry PhD candidate at Oregon State University, is using LandTrendr to study the intersection of wildfire and insects.

Specifically, Meigs is examining the large wildfires that have ravaged Washington and Oregon since 1985, and how outbreaks of the mountain pine beetle and western spruce budworm affect subsequent fire activity. “When there’s drought, stress, a higher susceptibility to infestation, we can see the dieback of forest,” he said.

The LandTrendr algorithm incorporates satellite images of the regions affected by fire and bugs with Meigs’ own fieldwork and historical aerial data from the U.S. Forest Service, which has long used airplanes to survey insect infestations. “There were things we couldn’t detect or see before, but now we’re able to,” Meigs said.

Below is a video showing a LandTrendr visualization of the Pacific Northwest. Kennedy explains how it works: Stable evergreen forests are represented by the blue areas; when a mountain pine beetle infestation erupts, in this case in the Three Sisters area of Oregon, the imagery glows red. And when a slow-moving western spruce budworm moves into an area–there, the southern foothills of Mount Hood–it morphs yellow.

Could LandTrendr help predict climate change? Possibly. “We can’t see the future, we can only document with the satellites what has happened. But the whole game with science is to develop understandings that allow for prediction,” Kennedy says. “My hope is that by creating these maps and capturing these processes in ways we haven’t been able to see them before, we can test [climate change] hypotheses” by documenting where, when and if predicted effects occur, he said.

While Meigs’ study of insects and wildfire is largely retrospective, it has the potential to aid in future forecasting efforts. “We have a baseline to measure future change,” he says. “By seeing the conditions leading up to big insect outbreaks or wildfires, we may be able to recognize them as they emerge in the future.”

A new study shows the tiny insects orient themselves by the stars. Image via Current Biology, Dacke et. al.

Science has shown us that a number of organisms use the stars for navigation: songbirds, harbor seals and, of course, humans. But a new study by a team of Swedish and South African researchers published today in the journal Current Biology indicates that a rather unexpected creature can be added to this list—the lowly dung beetle.

The beetles are known for creating small balls made of animal feces (i.e. dung) and rolling them in straight lines over long distances. They do this because the dung is their main food source—and other beetles often try to steal the dung once it’s been rolled into a ball. The surest way of retaining the valuable dung once it’s been packed into a ball is to move it away from the original dung pile as quickly as possible:

Researchers, though, have long been mystified by the tiny beetles’ ability to roll the dung balls in straight lines at night. “Even on clear, moonless nights, many dung beetles still manage to orientate along straight paths,” said lead author Marie Dacke of Lund University in Sweden. “This led us to suspect that the beetles exploit the starry sky for orientation—a feat that had, to our knowledge, never before been demonstrated in an insect.”

To test the hypothesis, the scientists set up a circular ring with a radius of about 4 feet outside and placed a dung pile at the center. They tested how long it took the beetles to reach the ring from the center—a measure of how straight their paths were—and found that their navigational abilities were relatively similar with either a full moon in the sky or at least a clear view of the stars. When they placed tiny blinders on the beetles’ eyes or subjected them to overcast conditions, though, their paths became much more windy.

Next, they placed a number of beetles in a planetarium and performed a similar test. Their paths were straightest with all the stars turned on, but were almost as true with just the Milky Way—indicating that they are particularly dependent on the Milky Way’s streak of light for navigation.

Image via Current Biology, Dacke et. al.

When the researchers turned on a large number of dim stars—many of which lie in the band of the Milky Way—the beetles’ navigation speed still remained similar. It was only when they left on just 18 of the brightest stars that their pathways became significantly windier.

The authors say that this proves that the beetles don’t rely on one particular star or celestial object for navigation, but rather take in the totality of the Milky Way—which appears as a startlingly bright band of light in many rural areas—to orient themselves on the ground.