What’s the News: Biochemists at the University of Arizona have found a promising new way to fight disease-carrying mosquitoes. In their research project, published in the journal PNAS, the scientists blocked mosquitoes’ ability to digest blood, making blood-sucking deadly to the winged pests. This technique could someday be used alongside other strategies to battle mosquitoes, like repellents and traps.
Scanning electron micrograph images of the nut (A,B)
and screw (C, D) in the leg joint of a Papuan weevil
What’s the News: Biologists spend lots of time poring over nature’s nuts and bolts. Now, for the first time, they’ve found a biological screw and nut—previously thought to be an exclusively human invention. The legs of beetles called Papuan weevils, researchers report today in Science, have a joint that screws together much like something you’d find in the hardware store.
From across the pond comes a ravishing collection of scientific imagery. The Wellcome Collection, a London museum, has just announced the winners of its Wellcome Image Awards.
The 21 award winners, selected from images acquired by the Wellcome Collection over the last 18 months, were chosen both for their ability to enhance scientific understanding and for their aesthetic appeal. Many use colour to better illustrate hard-to-see features. [New Scientist]
DISCOVER: The Alluring and Alien Sights of a Bee in Ultra Close-Up
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In the realm of meteorology, bats, birds, and insects are usually considered “animalas non grata,” since they create unwanted noise in the Doppler radar readouts used to study storms. But now, thanks to better radar station networking and the sharing of unfiltered data, ecologists have realized that these radar systems can be used as powerful animal tracking tools.
At last week’s American Association for the Advancement of Science meeting, researchers Thomas Kunz, Winifred Frick, and Phillip Chilson explained how Dopplar data can be used by ecologists. They call their new discipline aeroecology.
This melding of meteorology and ecology started with an “Aha!” moment:
“Dr Kunz and I were meeting Dr Chilson about a year ago over breakfast and they kept talking about the ‘QPE’, and finally I asked what it is,” Dr Frick told the meeting. It stands for quantitative precipitation estimator — a numerical method to measure how much rain there is in a storm front. “I paused and said, ‘you can estimate the number of raindrops in a raincloud? Do you think we could estimate the number of bats in a bat cloud?’” To calibrate their experiment, the team took a bat into a chamber where the degree to which it reflects radio waves could be measured. “From those measurements and using radar, we’ve been able to adapt those QPE measurements to a ‘QBE’ – a quantitative bat estimator,” Dr Frick said. [BBC News]
Fleas are remarkable jumpers: They can travel 200 times their own body length in a single leap, and can withstand acceleration forces of 100 Gs. But exactly how do they make such incredible jumps? Although we’ve known for decades that fleas store energy in a springy protein called resilin before they launch into the air, it’s remained a mystery whether they use the flea-equivalent of feet (called tarsi) or knees (called trochantera) to transmit that energy to the ground. But with 21st-century high-speed cameras, researchers have now put the debate to rest: the answer is in the feet.
Now, the first task in experimenting with fleas is to find fleas. Luckily, the warmhearted individuals at England’s St. Tiggywinkles Wildlife Hospital Trust have flea-ridden hedgehogs just waiting to lose a few bugs–and so that wonderfully named hospital donated a few fleas to a good cause.
The study, published in the Journal of Experimental Biology, included both video and flea-leap simulations. But the researchers–led by Gregory Sutton at the University of Cambridge–made their first insights using the same methods that were used decades ago:
To everything there is a season. Even the sexual proclivities of butterflies.
Yale researchers have found that male butterflies do not always take the lead in courting females at mating times. In some instances it’s the females that open the negotiations, and, curiously, the deciding factor seems to be the conditions in which they grew up as larvae—whether it was the dry, cool season, or the wet and warm season.
When certain caterpillars are raised in warm, moist conditions they grow into what some would consider traditional roles — males pursuing demure females. But new research has found that when they are raised in dry, cool conditions, it’s the ladies that become aggressive adults, actively courting the guys. [AP]
Among squinting bush brown butterflies, the species tracked in this study, both male and female sport what look like eye spots on their wings. The white spots in the center (the pupil of the eye) reflect light in the ultraviolet range, which appears to be the key to the butterflies‘ mating behavior.
“Cool temperatures increase the UV reflectance of female sexual ornaments, warmer temperatures increase the UV reflectance of male sexual ornaments. These changes are not visible to humans because we do not see UV,” explains postdoctoral fellow Dr Kathleen Prudic. However butterflies can see UV, so by developing more attention-grabbing eye spots, females born in the dry season are able to attract males. [BBC News]
Don’t you forget about bumblebees. While DISCOVER and others have extensively covered the mysterious colony collapse disorder that’s been crashing honeybee populations around the world, bumblebees have not escaped the tide of doom.
Sydney Cameron leads a team that just published a new study of bumblebees in this week’s Proceedings of the National Academy of Sciences, and tallied up some scary numbers.
The relative abundance of four species of bumble bees over the past few decades has dropped by more than 90%—and those disappearing species are also suffering from low genetic diversity, which makes them that much more susceptible to disease or any other environmental pressures. [TIME]
In addition, the geographic ranges of those species shrunk precipitously—between 23 and 87 percent, depending upon the case. That reduction in range could have catastrophic impacts on agriculture:
The first study of sleep in bees, published this week in the Proceedings of the National Academy of Sciences, found that the tired bees lag just like sleep-deprived humans do. Too bad bees don’t have coffee. Says lead researcher Barrett Klein:
“When deprived of sleep, humans typically experience a diminished ability to perform a variety of tasks, including communicating as clearly or as precisely. We found that sleep-deprived honey bees also experienced communication problems. They advertised the direction to a food site less precisely to their fellow bees.” [Daily Mail]
So how do you keep bees awake when they don’t need to cram for a calculus final? You make them magnetic. Klein attached a piece of either steel or non-magnetic metal to the bees’ backs. Then all through the night, the researchers swung a magnet over the hive three times a minute–a device they call the “insominator.” This jostled the bees with the magnetic steel on their backs and kept them from sleeping.
Imagine taking a course of antibiotics and suddenly finding that your sexual preferences have changed. Individuals who you once found attractive no longer have that special allure. That may sound far-fetched, but some fruit flies at Tel Aviv University have just gone through that very experience. They’re part of some fascinating experiments by Gil Sharon, who has shown that the bacteria inside the flies’ guts can actually shape their sexual choices.
The guts of all kinds of animals, from flies to humans, are laden with bacteria and other microscopic passengers. This ‘microbiome’ acts as a hidden organ. It includes trillions of genes that outnumber those of their hosts by hundreds of times. They affect our health, influencing the risk of obesity and chronic diseases. They affect our digestion, by breaking down chemicals in our food that we wouldn’t normally be able to process. And, at least in flies, they can alter sexual preferences, perhaps even contributing to the rise of new species.
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Not Exactly Rocket Science: An Introduction to the Microbiome
80beats: Scientists Peer Into the Brain of a Fruit Fly in Mid-Flight
80beats: Alcoholic Fruit Flies Don’t Know When to Say When
Image: Wikimedia Commons
For most insects, walking onto a spider’s web and disturbing the sticky threads would be a very bad idea. The distinctive vibrations of wriggling prey only serve to draw the spider closer and inevitably ends in the insect getting bitten, wrapped in silk and digested. But this story doesn’t always unfold in the spider’s favour. Some vibrations aren’t made by helpless prey, but by an assassin lurking on the web.
The assassin bug (Stenolemus bituberus) is a spider-hunter. Sometimes, it simply sneaks up to spiders on their own webs before striking, plunging its dagger-like mouthparts into its prey. But it also has a subtler technique. Sitting on the web, it plucks the silken threads with its legs, mimicking the frequency of weakly struggling prey. These deceptive vibes are an irresistible draw to the spider, who rush towards their own demise.
For more devious details, read the rest of this post at Not Exactly Rocket Science.
Not Exactly Rocket Science: Assassin bugs deceive spiders with coat of many corpses
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Video: Anne Wignall / Macquarie University