Tag Archives: insect

Trillions of cicadas emerge once in 17 years. This is that year

It’s called Brood X: a brood of cicadas in the US that only emerges from the earth once every 17 years. They’ve been in a sort of pseudohibernation, feeding on plant sap, waiting, biding their time — and the time is also here. In spring 2021, the trillions of cicadas will emerge, laying their eggs in trees which will hatch 4 to 6 weeks later in more than a dozen states. Then their offspring will head back underground until 2038.

Image credits: Wiki Commons.

The year of the cicada

Researchers call them Magicicada, and it’s a fitting name as their behavior is eerily mystical. They don’t just come out whenever, and they don’t follow a yearly pattern either. They spend either 13 or 17 years underground, feeding on xylem fluids from the roots of deciduous forest trees in the eastern United States. Then, like clockwork, one huge brood comes out — and they’re only active for a few weeks.

Researchers believe the cicadas are genetically programmed to behave like this, but they’re not entirely sure why. It could be that they come out only in prime years (like 13 or 17) to confuse predators, but the mystery of cicadas’ love affair with this unusual lifestyle is far from solved. But what we do know is that when the cicadas do come out, there’s a lot of them.

From New York to Illinois, trillions of cicadas from Brood X (Brood 10) are bound to emerge. We’re talking densities of 1.5 million per acre, a stunning and menacing swarm… that contrary to popular belief, is completely harmless.

Cicadas are often mistaken for locusts, but they’re anything but locusts. They don’t cause long-lasting damage to trees because they don’t eat leaves or branches, and they cause very limited agricultural damage. After more than 16 years of slowly sucking tree roots, Brood X cicadas come out with their energy levels saturated. Many of them don’t feed at all once they leave the underground.

“There will be some crop damage, especially to orchards, but we don’t expect a disaster,” said IU Bloomington biologist Keith Clay in 2004, the last time Brood X came above ground.

Although the idea of a gigantic swarm of insects emerging from the earth can sound scary, there’s no reason to worry. If anything, it’s an opportunity to witness a spectacular part of nature we don’t often get a chance to see. It doesn’t happen anywhere else, and if you live in the eastern US, you may see it in your own backyard. It’s a fascinating and unique moment of nature.

2004 Brood X swarm in Ohio. Image via Wiki Commons.

“Cicadas don’t bite, and they don’t attack people,” Clay said in 2004. “They are not very active when the sun goes down, so the massive noise we’ll hear in the daytime will subside, allowing people to sleep.”

Brood X (Brood 10), the Great Eastern Brood, is one of 15 broods of periodical cicadas that appear regularly throughout the eastern United States. It is one of the largest if not the largest, and it has the greatest range and concentration of any of the 17-year cicadas.

Emergence holes underneath flagstone

Cicada broods in eastern US have been noted for centuries. Historical accounts cite reports of 15- to 17-year recurrences of enormous numbers of “locusts” — which were actually cicadas. Pehr Kalm, a Swedish naturalist visiting Pennsylvania and New Jersey in 1749 on behalf of his nation’s government, observed one such emergence. He described it in a Swedish academic journal in 1756:

“The general opinion is that these insects appear in these fantastic numbers in every seventeenth year. Meanwhile, except for an occasional one which may appear in the summer, they remain underground. There is considerable evidence that these insects appear every seventeenth year in Pennsylvania.”

Researchers now are also interested in cicadas, and this emergence represents a chance to study them in greater detail.

“Given that Brood X is not going to emerge for another 17 years, this opportunity represents a once-in-a-researcher’s-lifetime opportunity to study the impacts of such an event,” said Michael Bowers, program director in NSF’s division of environmental biology, in 2004. “This is the first study to experimentally determine the impact of cicada emergence, adult movement and their impact on woody plants. Cicadas are a major insect herbivore for which we have only limited information.”

Researchers extract DNA from insects embedded in resin

For the first time, researchers have successfully extracted genetic material from insects embedded in resin samples. It’s not exactly Jurassic-age DNA but researchers say the technique could be used for older resin inclusions.

Resin with embedded ambrosia beetles. Image Credits: David Peris.

The idea of extracting DNA from resin-embedded organisns inevitably brings back memories of “Jurassic Park”. But despite being a globally acclaimed movie, Jurassic Park isn’t exactly scientific accurate — as you may have guessed.

For starters, DNA has a half life of 521 years. In 521 years, 50% of it is destroyed, in 1042 years, 75% of it is destroyed, and so on. Even if you had a perfectly preserved piece of DNA, it would be completely destroyed after 6.8 million years. In practical situations, the oldest DNA ever analyzed was under 2 million years. Finding the DNA of dinosaurs, which went extinct 65 million years ago, is not what you’d call realistic. But the DNA of insects trapped in amber may be accessible yet.

In the latest study, Senckenberg scientist Mónica Solórzano-Kraemer, together with lead authors David Peris and Kathrin Janssen of the University of Bonn and additional colleagues from Spain and Norway set much lower ambitions. They successfully extracted genetic material from insects embedded in two- and six-year-old resin samples. It may not be as exciting as Jurassic Park, but it’s the first time this has been done and it’s the first time researchers have demonstrated that DNA can be preserved in resin.

“We have no intention of raising dinosaurs,” says Dr. Mónica Solórzano-Kraemer of the Senckenberg Research Institute and Natural History Museum. “Rather, our current study is a structured attempt to determine how long the DNA of insects enclosed in resinous materials can be preserved.”

“Our study fundamentally aimed to clarify whether the DNA of insects embedded in resin continues to be preserved. Using the polymerase chain reaction (PCR) method, we were able to document that this is, indeed, the case in the six- and two-year-old resin samples we examined,” explains Solórzano-Kraemer.

Senckenberg researcher Mónica Solórzano-Kraemer with one of the examined resin samples. Image Credits: Xavier Delclòs.

It’s not uncommon to find insects trapped in amber from centuries, millennia, or even millions of years ago. However, all previous DNA tests of inclusions have failed, not only due to DNA decay, but also to the environmental impacts suffered by the DNA.

Now, at least, researchers know that when insects become embedded in resin, their DNA isn’t automatically destroyed.

“We are now able to show for the first time that, although it is very fragile, the DNA was still preserved in our samples. This leads to the conclusion that it is possible to study the genomics of organisms embedded in resin,” adds Solórzano-Kraemer.

It’s still not clear what the ‘shelf-life’ of resin-embedded DNA is, though. The best way to figure this out is to keep carrying out more and more experiments on resin-trapped insects of different ages.

The study was published in PLOS.

Fossil Friday: oldest millipede shows how quickly terrestrial life evolved

A 425-million-year-old fossil millipede found on the island of Kerrera (Scotland) is the oldest known fossil of an insect, according to researchers at The University of Texas at Austin (UT).

The millipede fossil.
Images British Geological Survey

The finding points to terrestrial insects (and the plants they ate) evolving at a much more rapid pace than previously assumed, the team explains. The age of this millipede (Kampecaris obanensis) would mean that terrestrial ecosystems evolved from humble water-hugging communities to sprawling, complex forests in just 40 million years.

Big, old bug

“It’s a big jump from these tiny guys to very complex forest communities, and in the scheme of things, it didn’t take that long,” said Michael Brookfield, a research associate at UT Austin’s Jackson School of Geosciences and lead author of the paper. “It seems to be a rapid radiation of evolution from these mountain valleys, down to the lowlands, and then worldwide after that.”

Using a refined dating technique developed in the Jackson School’s Department of Geological Sciences, the team established that the fossil is 425 million years old. This would put it at around 75 million years earlier than our previously estimated date for the first millipedes — as determined using a technique known as molecular clock dating, which is based on DNA’s mutation rate.

This finding ties in well with other research that found land-dwelling stemmed plants in Scotland were also 425 million years old and 75 million years older than molecular clock estimates.

Naturally, there could be older fossils of insects or plants out there, Brookfield notes, but they haven’t been found yet. So for now, we’ll have to use this as the earliest evidence of their presence.

Still, the fossil points to land ecosystems evolving and diversifying much more quickly than previously assumed.

The paper “Myriapod divergence times differ between molecular clock and fossil evidence: U/Pb zircon ages of the earliest fossil millipede-bearing sediments and their significance” has been published in the journal Historical Biology.

Bumblebees carry heavy loads in ‘economy’ flight mode

Bumblebees can carry surprisingly heavy loads of nectar, a new paper explains, potentially bearing up to their own body weight in the sweet liquid. Furthermore, the insects use a more energy-efficient flight pattern when heavily encumbered.

Image credits Suzanne Williams.

The humble bumblebees definitely lift, the authors report. In fact, they may be the ‘big lifters’ of the insect world. The team set out to understand how the bumblebees manage to fly with such impressive loads, and uncovered the surprising flexibility and adaptability of their flight mechanics.

The burdens we bear

“[Bumblebees] can carry 60, 70, or 80 percent of their body weight flying, which would be a huge load for us just walking around,” said Susan Gagliardi, a research associate in the College of Biological Sciences at the University of California (UoC) Davis and co-author of the paper.

“We were curious to see how they do it and how much it costs them to carry food and supplies back to the hive.”

For the study, the team emptied a snowglobe (to be used as an experimental chamber) and released bumblebees inside it. Each insect had various lengths of solder wide attached to it in an effort to adjust its weight. High-speed video cameras were used to record their wing beats and movements, while the team charted how much energy each bee needed to expend.

“We have the bees in a little chamber and we measure the carbon dioxide they produce. They are mostly burning sugar so you can tell directly how much sugar they are using as they are flying,” Gagliardi said.

Unlike our aircraft, which generate lift from the smooth flow of air over their fixed, horizontal wings, bees move their wings at a high angle to generate tiny wind vortices. These churning bodies of air curl around the insect’s wings and lift them up. The team explains that while the bee’s approach does generate more lift than the smooth-airflow approach out planes rely on, it’s also more unstable mechanically — the vortices are chaotic and they break down very quickly. Bees are only able to fly because they move their wings rapidly to re-generate the vortices.

We didn’t know, however, the energy-efficiency of this mode of flight. It seems reasonable to assume that the bees would use less energy the lighter their load is, but the team was surprised to find out this isn’t the case: bumblebees are actually more efficient per unit of weight when they’re heavily laden. In other words, they’re more “economical in flying” when they’re heavily loaded — “which doesn’t make any sense in terms of energetics,” says Stacey Combes. Combes is an associate professor in the Department of Neurobiology, Physiology, and Behavior at the UoC and the paper’s lead author.

The team explains that bumblebees have two ways to deal with heavy loads. They can either increase the amplitude of their strokes (i.e. how far the wings flap), which helps but isn’t enough on its own for the heaviest of loads, or increase the frequency of their wingbeats, which helps them stay aloft but costs more energy. However, they also observed an alternative flying mode being used — one the team calls their “economy mode” — in which the bees can carry lots of nectar while using less energy than faster flapping requires.

Exactly how they do this is still unclear, Combes said, although the team believes it may involve the wings rotating when reversing direction between strokes. However, it seems to be something that the bees themselves can choose to do, or not. The team explains that overall, when lightly-loaded or rested, the bumblebees were more likely to increase the frequency of their wingbeats. However, they switch to the ‘economy mode’ only when heavily loaded, which produces more lift without an increase in flapping frequency.

“It turns out to be a behavioral choice they are making in terms of how they support the load,” Combes said.

But why don’t they always fly in this mode? The team is still unsure, but it may be that high wingbeat frequency brings other advantages to the table that are more attractive to the bees in a lighter-load scenario.

“When I started in this field there was a tendency to see them as little machines, we thought they’ll flap their wings one way when carrying zero load, another way when they’re carrying 50 percent load and every bee will do it the same way every time,” Combes adds.

“This has given us an appreciation that it’s a behavior, they choose what to do. Even the same bee on a different day will pick a new way to flap its wings.”

The paper “Kinematic flexibility allows bumblebees to increase energetic efficiency when carrying heavy loads” has been published in the journal Science Advances.

Scientists devise tiny robot insects that can’t be crushed by a flyswatter

In the future, swarms of tiny flying soft robots could zip through the sky, performing various tasks such as monitoring the environment, remote repairs, perhaps even pollination. In Switzerland, engineers have recently demonstrated a new type of insect-like flying robots that may do just that. But don’t let their fragile appearance deceive you — these tiny bots are so strong they can resist being battered by a flyswatter.

The DEAnsect. Credit: EPFL.

Central to the proper functioning of this tiny soft robot, known as DEAnsect, are artificial muscles. Researchers at the École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland fitted the thumbnail-sized robots with dielectric elastomer actuators (DEAs) — hair-thin artificial muscles — which propel the artificial insects at about 3cm/second through vibrations.

Each DEA contains an elastomer membrane sandwiched between two soft electrodes. When a voltage is applied, the electrodes come together, compressing the membrane; once the voltage is switched off, the membrane returns to its original size. Each of the robot’s legs has three such muscles.

The vibrations caused by switching the artificial muscles on and off (up to 400 times a second) allows the DEAnsect to move with a high degree of accuracy, as demonstrated in experiments in which the robots followed a maze (shown in the video).

These extremely thin artificial muscles allowed the entire design to be streamlined in a very compact frame. The power source only weighs 0.2 grams, while the entire robot, battery and other components included, weighs one gram.

“We’re currently working on an untethered and entirely soft version with Stanford University. In the longer term, we plan to fit new sensors and emitters to the insects so they can communicate directly with one another,” said Herbert Shea, one of the authors of the new study published in Science Robotics.

Beetle trapped in amber pushes back insect pollination by 50 million years

Paleontologists in China and the US have documented the earliest case of insect pollination thanks to a 99-million-year-old beetle preserved in amber. The pristine fossil contains traces of pollen showing that the evolution of plants and animals during this time period were closely intertwined.

Illustration of A. burmitina. Credit: Ding-hau Yang.

David Dilcher, an emeritus professor at the Department of Earth and Atmospheric Science at the Indiana University, performed a morphological review of the 62 grains of pollen found in the amber, which came from a mine in northern Myanmar. Dilcher is one of the world’s foremost experts in amber fossilization, who also has a lot of experience studying the earliest flowering plants.

The pollen was not easy to find. To the untrained eye, the tiny granules don’t look like anything important. However, the researchers analyzed the beetle’s body hairs under a confocal laser microscope, which made the pollen grains glow, contrasting strongly with the darkness of the insect’s shell.

This is the earliest known physical evidence of insect pollination. Credit: Nanjing Institute of Geology and Palaeontology.

The shape and structure of the pollen — particularly the pollen’s size, “ornamentation” and clumping ability — show that it evolved to spread through contact with insects.  The analysis showed that the pollen came from a flower species in the group eudicots, which is one of the most common types of flowering plant species.

As for the beetle trapped in the amber, it belongs to a new species that the researchers named Angimordella burmitina. Using X-ray microcomputed tomography (micro-CT), Dilcher and colleagues could study the insect’s shape and physical features in minute detail without having to disturb or damage the fossil in any way whatsoever. Armed with a 3-D digital model of the beetle, the researchers could clearly see several specialized body parts signaling the insect’s role as a pollinator, including the shape of the body itself and pollen-feeding mouthparts.

A close up of A. burmitina in amber. Credit: Nanjing Institute of Geology and Palaeontology.

Researchers determined the age of the amber fossil from the age of other known fossils retrieved from the same location. At nearly 100 million years old — during a time when pterodactyls were still alive, roaming the sky — the discovery pushes back the earliest documented instance of insect pollination to about 50 million years earlier.

“It’s exceedingly rare to find a specimen where both the insect and the pollen are preserved in a single fossil,” said Dilcher. “Aside from the significance as earliest known direct evidence of insect pollination of flowering plants, this specimen perfectly illustrates the cooperative evolution of plants and animals during this time period, during which a true exposition of flowering plants occurred.”

The findings appeared in the journal Proceedings of the National Academy of Sciences.

Insects in Germany have declined by up to two-thirds in ten years

In 2017, researchers sounded the alarm when they found that the number of flying insects had dramatically fallen in recent times in Germany. A new study that analyzed a broad range of species in three protected German areas confirmed these fears, finding that some populations had declined by up to two-thirds in the last decade.

Two years ago, an international team of researchers reported that over the last 27 years, flying insect biomass has plummeted by 75 percent in Germany. Land use or changes in weather could not alone explain this dramatic drop in insect biomass.

Insects, be they land-loving or wind trailing, are essential to ecosystem functioning and health. They’re responsible for pollinating 80 percent of wild plants and provide food for a wide range of species, including 60 percent of all birds.

In a new study, researchers led by Sebastian Seibold and Wolfgang Weisse, both professors of terrestrial ecology at the Technical University of Munich, analyzed data on flying insects from 290 sites within forest and grassland habitats. The sites were surveyed by biologists between 2008 and 2017, who counted flying insects, as well as arthropods like spiders and millipedes, using nets and traps.

The results suggest that both in meadows and in forests, the number of species decreased by about a third during the study period. Their biomass, which indicates population size, decreased by 67% in grasslands and 40% in forests.

Among the factors that may be responsible for the decline, the researchers have identified deforestation, invasive species, urbanization, global heating, wetland and river alterations, and agriculture. The latter is believed to be responsible for roughly half of the impact.

The German researchers found that insect decline was particularly enhanced in grasslands surrounded by arable land. Species that did not cover long distances shrank the most in such areas. Meanwhile, in forests, it was mainly species that traveled long distances that suffered the most, possibly because they come into contact with agriculture during their migration.

“The decline affected rare and abundant species, and trends differed across trophic levels. Our results show that there are widespread declines in arthropod biomass, abundance and the number of species across trophic levels. Arthropod declines in forests demonstrate that loss is not restricted to open habitats,” the authors wrote in the journal Nature.

These frightening findings suggest that insect decline is very much real and just as bad as previously reported by other studies. And, this certainly isn’t happening just in Germany.

Earlier this year, a metastudy found that half of all the world’s insect species are in decline and a third are already endangered. The orders Lepidoptera, Hymenoptera, and Coleoptera (butterflies, bees, and beetles, respectively), are the worst-hit groups. One of the studies included in the analysis shows that the number of widespread butterfly species on farmed land in the UK fell by 58% between 2000 and 2009. Bees are also struggling: Oklahoma lost half of its bumblebee species between 1949 and 2013. The number of honeybee colonies in the US was 6 million in 1947, but 3.5 million have been lost since. Beetle species are also declining, especially dung beetles, according to this meta-analysis.

“Our results suggest that major drivers of arthropod decline act at larger spatial scales, and are (at least for grasslands) associated with agriculture at the landscape level. This implies that policies need to address the landscape scale to mitigate the negative effects of land-use practices,” the German researchers wrote.

Since agriculture is the main driver of this decline, policymakers, farmers, and conservation efforts have to work in sync in order to coordinate a reversal of this dire trend. There is some progress in this respect. This year, Germany’s Farmers’ Association voluntarily ceded arable land back to nature, creating a 230,000 km-long and 5-meter-wide flower strip corridor. Insecticides such as neonicotinoids and the herbicide glyphosate (Roundup) have also come into scrutiny for their potential ill effects on biodiversity. Measures that restrict their use may also play a major role in reviving insect populations.

Grasshopper.

Grasshoppers, silkworms, giant cicadas are a good source of antioxidants — if you eat them

Insect-based dinner might not sound very enticing but new research shows it’s definitely packed full of antioxidants.

Grasshopper.

Scrumptious!
Image credits Will Brown / Flickr.

A new study reports that edible insects and other creepy crawlies are comparable foods such as olive oil and orange juice in antioxidant content. The findings come as an effort to further entice people to consider insects as part of their diet, a move that would have huge implications for the sustainability and environmental footprint of agriculture worldwide.

Young grasshopper — sautéd

“At least 2 billion people — a quarter of the world’s population — regularly eat insects,” says Prof. Mauro Serafini, lead author of the study published in Frontiers in Nutrition. “The rest of us will need a bit more encouragement.”

“Edible insects are an excellent source of protein, polyunsaturated fatty acids, minerals, vitamins and fiber. But until now, nobody had compared them with classical functional foods such as olive oil or orange juice in terms of antioxidant activity.”

The fact of the matter is that what most of us put on the table, combined with how many people Earth houses currently, simply doesn’t make for a sustainable future. Insects can help us address this issue; they have a much more modest environmental footprint than livestock, and are a great source of nutrients. However, most people are quite reluctant to come anywhere near these animals, let alone put them in their mouth.

Those who do, however, will likely see the benefits, the new paper reports. According to the analysis, crickets pack 75% the antioxidant power of fresh OJ, and silkworm fat twice that of olive oil. The team hopes that the findings will provide the nudge many people need to consider including these insects into their diets. That taste and presentation are key elements of food, they write, but hope that the ‘selfish and immediate incentives’ provided by the insects’ antioxidant properties will be enough to convince some consumers.

“Consumption of foods rich in antioxidants, such as fruit and vegetables, play an important role in the prevention of oxidative stress-related diseases such as cardiovascular disease, diabetes and cancer,” the study explains.

Antioxidants are substances that bind free-radicals, uncharged molecules which are typically highly reactive and short-lived that damage cells and tissues. The team tested a range of commercially-available insects and invertebrates for their antioxidant activity. The inedible parts of these animals (such as wings or stingers) were removed, after which the insects were ground up.

Two parts were extracted from each species: a fat- and a water-soluble fraction. Each extract was then tested for antioxidant content and activity. Water-soluble extracts of grasshoppers, silkworms, and crickets have “antioxidant capacity 5-fold higher than fresh orange juice,” the authors report. The fat-soluble fractions of evening cicadas and silkworms showed twice the antioxidant activity of olive oil. “For perspective, using the same setup we tested the antioxidant capacity of fresh orange juice and olive oil — functional foods that are known to exert antioxidant effects in humans,” adds Serafini.

Fat-soluble fraction.

Trolox Equivalent Antioxidant Capacity (TEAC) of fat-soluble extracts compared to olive oil.
Image credits Selena Ahmed et al., (2019), Frontiers.

Water-soluble fraction.

Trolox Equivalent Antioxidant Capacity (TEAC) of water-soluble extracts compared to fresh orange juice.
Image credits Selena Ahmed et al., (2019), Frontiers.

 

However, these values are representative for the dry, isolated extracts, which aren’t something you’d want to eat. The water content of the insects was within 2-7% while orange juice is 88% water; most foods fall somewhere in between the two. A glass of 88% water, 12% grasshopper or silkworm extract would have around three-quarters of the antioxidative effect of a glass of OJ.

Another interesting finding is that the insects showed a lower total content of polyphenols (a major source of plant-derived antioxidant activity) across the board compared to orange juice. However, this compound alone couldn’t account for the full antioxidant capacity seen in the study — suggesting that insects also contain a yet-unknown substance with antioxidant capacity.

“The in vivo efficiency [i.e. in humans] of antioxidant-rich food is highly dependent on bioavailability and the presence of an ongoing oxidative stress. So as well as identifying other antioxidant compounds in insects, we need tailored intervention studies to clarify their antioxidant effects in humans,” Serafini says.

“In the future, we might also adapt dietary regimens for insect rearing in order to increase their antioxidant content for animal or human consumption.”

The paper “Antioxidant Activities in vitro of Water and Liposoluble Extracts Obtained by Different Species of Edible Insects and Invertebrates” has been published in the journal Frontiers in Nutrition.

Lab engineered meat? How about lab-grown insect meat?

By now, the fact that the world is eating too much meat should surprise no one. In addition to ethical concerns, meat is associated with a host of other environmental issues — greenhouse gas emissions, water usage, you name it. In recent years, a promising new solution has been emerging: lab-grown meat. The idea is to clone meat in a lab, a process that’s cruelty-free, eco-friendly, and cost-competitive with “real” meat. That last part is still a work in progress, but things are slowly looking up.

Now, a team of researchers put a new twist on that idea: what if instead of growing meat, we grow insect meat?

Image credits: Paolo C.

In theory, growing artificial meat isn’t that complicated. The technology is there, the rough infrastructure exists, but the ingredients are a pain — specifically, the nutrients needed to feed the cells. This generally comes in the form of delicate serums containing animal blood, which means that the resulting product is not only very expensive but also not cruelty-free. In this current state, cultured meat is hardly a reliable solution.

Insect meat, however, is different.

The tissues of invertebrates are different from those of mammals in a number of ways, some of which are not exactly clear. However, it is clear that insects are more resilient to a range of different conditions (temperature, pH, humidity), and they are also less demanding in terms of nutrients. In simple terms, mammals need a lot of micronutrients, while insects don’t.

So because their metabolism is simpler, growing insect cells might also be easier. This would make cultured insect meat more scalable and dramatically reduce costs. There’s also another advantage to cultivating insect cells: if they have sufficient nutrients, they endlessly propagate.

In a new study, Tufts biomedical engineer David Kaplan and colleagues describe how they can not only grow insect cells, but also make robots from them — or rather, robot components, such as bio-actuators. They also describe how other researchers built bio-actuators from insect cells in a variety of conditions.

“Insect muscle culture is prominent in the field of soft robotics. Researchers have constructed small scale robots or “bio-bots” from both mammalian and invertebrate biomass. Insect-derived bio-bots may be superior to bio-bots constructed from mammalian tissues or cells because insect tissue is tolerant to a wide range of environmental conditions,” the study reads.

Of course, while this is encouraging, growing insects for eating is a completely different affair — and researchers haven’t actually done this yet, they’ve simply shown that it could be done. We don’t really know how it would taste, and it wouldn’t be anything like an actual steak. You’d need to add a structure and micro-scaffolding to give it an edible form. Overall, there’s still a long way to do before it can hit the shelves.

“Despite this immense potential, cultured insect meat isn’t ready for consumption. Research is ongoing to master two key processes: controlling development of insect cells into muscle and fat, and combining these in 3D cultures with a meat-like texture,” said Natalie Rubio, lead author of the new study. “For the latter, sponges made from chitosan – a mushroom-derived fiber that is also present in the invertebrate exoskeleton – are a promising option.”

However, this potential justifies further investigation. At the current moment, our global consumption of meat just isn’t sustainable, and researchers are well aware of that.

“Due to the environmental, public health and animal welfare concerns associated with our current livestock system, it is vital to develop more sustainable food production methods,” Rubio added.

Accelerating development of sustainable foods can be done — whether or not insects will play a part of that remains to be seen.

The study was published in the journal Frontiers in Sustainable Food Systems.

 

Credit: Biology Letters.

Cave insects that have female penises evolved independently

Credit: Biology Letters.

Credit: Biology Letters.

Inside caves in Brazil, researchers have come across two peculiar insect species whose sexual organs are reversed. Unlike almost every other animal, the females have penis-like appendages and males have vagina-like pouches. In a new study, an international team of researchers from Japan, Brazil, and Switzerland investigated the evolutionary history of the two species. To their surprise, they found that the sex reversal in these insects evolved independently from one another.

Reversed sexual selection

The researchers studied three insects (AfrotroglaNeotrogla, and Sensitibilla), all belonging to the same genera. Afrotrogla and Neotrogla are particularly noteworthy because the females have a penis-like organ, termed a gynosome. This organ is used to anchor male vagina-like genitalia in a species-specific manner for up to days at a time, during which “voluminous and probably nutritious semen is passed to the female,” the authors of the new study wrote in Biology Letters

Although Sensitibilla belongs to the same tribus as Afrotrogla and Neotrogla, these insects do not have reversed organs. By studying the sex organs of all three, the researchers came to the conclusion that sexual organ reversal in the two identified insect species had evolved independently, and not before the species diverged.

Genital traits differ between sexes due to conflicting mating strategies. In most species of animals, male reproductive success increases with the number of mates, whereas female fitness does not improve with the number of mates (and can even be detrimental due to limited ova). In response, some males developed traits in their genitalia that enable them coercively mate with females, such as claspers and spines. In response, females developed traits for resistance or tolerance, such as pouches that accommodate spines or anti-clasping projections.  

However, in the dry and resource-scarce caves where Afrotrogla and Neotrogla live, the environment seems to have forced an organ reversal. Because food is scarce, males appear to have invested more resources into securing nutrients than for mating. In retaliation, the female had to assume the traditional role of the male. What’s more, in order to prevent the male from escaping with his sperm, the females evolved a hook that latches onto the male. Predation in the cave ecosystem may also have played a role in the odd sexual organ differentiation seen in these insects.

Males generally have higher potential reproductive and optimal mating rates than females. Therefore, sexual selection acts strongly on males. But for Afrotrogla and Neotrogla, their genital adaptations have been driven by reversed sexual selection with females competing for sperm. Writing in another paper published last month in the journal eLife, the same team of researchers reported that “the ability to obtain greater amounts of semen thanks to the valve [a switching valve at the entrance of the semen-storage organ] has led to fierce competition over semen among females, facilitating the evolution of the female penis.” Nothing similar is known among sex-role-reversed animals.

Honeybee.

Honeybee clusters act as ‘super-organisms’ to keep everyone safe during bad weather

New research investigates how bees shape and maintain their temporary travel-homes.

Honeybee.

Image via Pixabay.

Researchers from the Harvard University (HU) report that honeybees make a group effort to keep the colony safe during their travels. The study looked into the mechanisms by which the insects keep their temporary clumps intact during adverse weather conditions — and found a surprisingly complex system born from relatively simple beings.

Roadtrip!

Once every year, honeybee (Apis mellifera) queens leave the nest, with their subjects in tow, to establish new colonies. That’s faster said than done, however, and while the bees search for a new place of residence, they have to camp underneath the stars.

In order to keep everybody safe during these times, the bees draw together into masses usually referred to as clumps or clusters. These structures — constructed entirely out of living, buzzing bees clinging together — generally form into a cone-shape. When the weather takes a turn for the worse, however, these cones tend to change shape, previous research has shown. Most intriguingly, they seem to adapt their shape to the particular conditions they’re faced with — even if the bees, individually, have no way of knowing what shape would work best.

Curious to see how the bees knew what they had to do as conditions worsened, the HU team gathered wild bees and placed them in a container in the lab. Here, the bees were allowed to form a cluster from a movable apparatus that the team supplied for them.

After the cluster formed, the team moved their apparatus back and forth or up and down to pull on the cluster. These motions were intended to simulate the effect of wind pushing on the cluster’s support — for example a branch. The team’s cluster dutifully changed shape — in the case of back-and-forth movement, it flattened, slowly ‘hugging’ the device.

Honeybee clusters.

a) Bee clusters on a tree branch. b) The experimental set-up. c) The top panel shows the acceleration of the board versus time. The middle and bottom panels show how the bee cluster adapts its shape.
Image credits O. Peleg, J. M. Peters, M. K. Salcedo & L. Mahadevan, 2018, Nature Phys.

Such a shape is better suited to dealing with incoming wind, the team writes, just like a person lying on the ground versus somebody standing up in heavy winds.

The honeybees’ activity was recorded with slow-motion video cameras so that the team could track their movement on the cluster’s surface. By watching the insects’ movements, the team also came up with a hypothesis — the bees, after feeling themselves pulled from the ones they were holding on to, moved to a place of higher stress.

In order to test this idea, the group created a computer simulation of the honeybees and the cluster they form. Simulated bees on the outer surface were given the ability to feel stress and react to it by moving to a position of higher stress. In the end, the team writes, the virtual bees changed their cluster in the same way as real honeybees were observed to do in the lab — very strong evidence that the team’s theory was correct.

The simulations also helped explain why up and down movements didn’t elicit a shape-change from the cluster; these movements, the team reports, do “not lead to significant differential strains and thus no shape adaptation” — i.e. they don’t bother the colony enough to require a response.

“Together, our findings highlight how a super-organismal structure responds to dynamic loading by actively changing its morphology to improve the collective stability of the cluster at the expense of increasing the average mechanical burden of an individual,” the paper concludes.

The paper “Collective mechanical adaptation of honeybee swarms” has been published in the journal Nature Physics.

NASA Explores the Use of Robotic Bees on Mars

Graphic depiction of Marsbee - Swarm of Flapping Wing Flyers for Enhanced Mars Exploration. Credits: C. Kang.

Graphic depiction of Marsbee – Swarm of Flapping Wing Flyers for Enhanced Mars Exploration. Credits: C. Kang.

Robot bees have been invented before, but Mars might be a place for them to serve a unique purpose. Earlier this year, it was revealed that the Japanese chemist Eijio Miyako led a team at the National Institute of Advanced Industrial Science and Technology (AIST) in developing robotic bees. So they’re not really bees; they’re drones. Miyako’s bee drones are actually capable of a form of pollination similar to real bees.

Bees have been the prime subject of many a sci-fi films including The Savage Bees (1976), The Swarm (1978), and Terror Out of the Sky (1978). In the 21st century, bees have been upgraded. Their robotic counterparts shall have an important role to play in future scientific exploration. And this role could very well be played out on the surface of Mars.

Now, NASA has begun to fund a project to create other AI-steered robotic bees for the future exploration of Mars. The main cause of experimenting with such mini robots is for the desirable need for speed. The problem is this: the traditional rovers sent to Mars in the past move very slowly. NASA anticipates an army of fliers to move significantly faster than their snail-like predecessors.

A number of researchers in Alabama are currently collaborating with a group based in Japan to design these mechanical drones. Sizewise the drones are very similar to real bees; however, the wings are unnaturally large. The lengthened wingspan was a well-needed feature to add since the Red Planet’s atmosphere is thinner compared to Earth’s. These small insect-like robots have been dubbed “Marsbees.”

If used, the Marsbees would travel in swarms and be able to return to some sort of a base, not unlike the way bees return to their hive. The base would likely be a rover providing a place for the Marsbees to be reenergized. But they would not have to come to this rover station to send out the information they’ve accumulated. Similar to satellites, they would be able to transmit their findings wirelessly. Marsbees would also likely be able to collect a variety of data. If their full development is feasible and economical, the future for Marsbees looks promising.

Finland baker launches bread made almost entirely of crickets

The food of the future is here: it’s baked in Finland, and it contains about 70 crickets.

Image credits: Fazer.

Bakeries are usually warm, cozy places, filled with pleasant, inviting scents. But if you were to visit one of Fazer’s bakeries in Finland, you might come across something else. The company has developed a new type of bread, which includes crickets for extra protein and nutrients.

“It offers consumers with a good protein source and also gives them an easy way to familiarize themselves with insect-based food,” said Juhani Sibakov, head of innovation at Fazer Bakeries.

“We made a crunchy dough to enhance taste and increase mouthfeel. The result is delicious and nutritious. Cricket bread is a good source of protein. Insects also contain good fatty acids, calcium, iron and vitamin B12.”

Fazer took advantage of a recent change in national legislation: Finland, along with five other countries (Britain, the Netherlands, Belgium, Austria and Denmark) removed a ban on insect use in the food industry, effectively allowing insects to be raised and marketed for food use. Sibakov said they had the bread ready since last summer, but they had to wait for the legislation to be passed before the bread could hit the shelves.

Each loaf contains crickets which have been dried, ground, and mixed with flour, wheat, and other seeds. Sara Koivisto, a student from Helsinki who tried the bread, told Reuters that “I don’t taste the difference … It tastes like bread.”

Whether or not other consumers will have the same opinion remains to be seen, but for now, Fazer, who has a sales figure of about 1.6 billion euros last year, plans to sell it in all 47 of its stores by next year. The price is €3.99 ($4.74), compared with €2-3 for a regular wheat loaf. However, in order for that to happen, they need to import more crickets, which they are currently bringing from the Netherlands.

Insects are commonly eaten in many parts of the world, with the UN listing more than 1,900 edible species that are eaten by 2 billion people. However, in the West, the idea of eating insects is just recently gaining traction, particularly among those seeking a gluten-free diet or wanting to protect the environment. Farming insects is touted as being less energy and water intensive, while also requiring less land. For instance, production of 150g of grasshopper meat requires just a few liters of water, while cattle requires 3290 liters to produce the same amount of beef. Fazer says that the cricket bread could be an easy way to accustom Western clients with insect-based food.

 

flying-insect

Flying insect biomass decreased by 75 percent over 27 years in nature reserves

Dutch researchers at Radboud University report that over the last 27 years, flying insect biomass has plummeted by 75 percent in Germany. The findings serve as a wakeup call given the current climate of accelerating decline in insect populations reported all over the world.

flying-insect

Credit: Pixabay.

Insects, be them land loving or wing buzzing, are essential to ecosystem functioning and health. They’re responsible for pollinating 80 percent of wild plants and provide food to a wide range of species, including 60 percent of all birds. Previously, scientists have identified a pattern of decline in insect diversity and populations. These studies, however, tend to focus on single species or taxonomic groups, which can fail to grasp the bigger picture.

Caspar Hallmann and colleagues at Radboud took a different route by assessing flying insect biomass, which indicates if the number of insects in a given area rose or fell, regardless of the species involved. The team measured flying insect biomass collected using Malaise traps from 63 natural reserves in Germany over 27 years. Malaise traps were deployed through the spring, summer, and early autumn, operating day and night. The catch was emptied at regular intervals, on average every 11.2 days.

The team found that flying insect biomass declined by 76 percent on average in just 27 years and by up to 82% in midsummer. The dramatic decline took place everywhere, regardless of the habitat type. Land use or changes in weather could not alone explain the steep drop in insect biomass. These depressing figures underscore how the entire flying insect community has been decimated over the last few decades, as reported previously by papers which found declines in vulnerable species such as butterflies, wild bees, and moths.

A malaise trap in a nature protection area in Germany. Credit: Hallmann et al (2017).

A malaise trap in a nature protection area in Germany. Credit: Hallmann et al (2017).

Since 2006, honeybee populations have drastically declined at the hand of a peculiar phenomenon called colony collapse disorder (CCD). Today, most bee species are in decline, with annual regional losses as high as 60 percent. Nobody is completely sure what causes CCD, but studies seem to point towards neonicotinoid pesticide use. Earlier this month, researchers reported that neonicotinoids were found in 75 percent of honey samples collected from all over the world.

Monarch butterfly populations have also been declining significantly, reaching the lowest count ever recorded during 2013-14 as a result of habitat loss, particularly the loss of milkweed (the species’ only food source), and mortality caused by the use of pesticides. West North America lost 95 percent of its Monarch butterflies over the last 35 years, according to a distressing recent report.

While the Dutch researchers focused on flying insect biomass in protected areas around Germany, a similar pattern of population decline is happening all over the world. Rodolfo Dirzo, an ecologist at Stanford University, developed a global index for invertebrate abundance that showed a 45 percent decline over the last four decades. 

“Although invertebrates are the least well-evaluated faunal groups within the IUCN database, the available information suggests a dire situation in many parts of the world,” says Dirzo.

Hallmann says that more work is required to investigate the full range of climatic and agricultural variables that might impact insect biomass. Whatever’s the case, evidence so far points towards humans interfering with insect habitats, foraging, and diet. We caused this mess and it’s up to us to clean it up.

“There is an urgent need to uncover the causes of this decline, its geographical extent, and to understand the ramifications of the decline for ecosystems and ecosystem services,” the authors concluded.

Scientific reference: Hallmann CA, Sorg M, Jongejans E, Siepel H, Hofland N, Schwan H, et al. (2017) More than 75 percent decline over 27 years in total flying insect biomass in protected areasPLoS ONE 12(10): e0185809. https://doi.org/10.1371/journal.pone.0185809

Insects see in much better resolution than we thought

We may have to re-think what we know about how the little creatures see.

Arthropods such as this Calliphora vomitoria fly have compound eyes. Image credits: JJ Harrison.

Insects see the world much differently from us, that much is clear. For the longest time, researchers thought they are unable to see fine images due to the way their eyes are built. Most insects have compound eyes which consist of many (up to thousands) tiny lens-capped ‘eye-units’. Together, these work to create a low resolution, pixelated image.

Contrasting to that, our own eyes have a single lens, a “megapixel camera” that can actively change the lens shape according to different needs and can keep both nearby and far away objects in sharp focus, based on our different needs. The end result of our eyes is a densely-packed, high-resolution image. Very different from that of insects — or at least that’s what we thought.

Researchers from the University of Sheffield’s Department of Biomedical Science challenge that long-held view. Working with colleagues from Beijing, Cambridge, and Lisbon, they found that insect compound eyes can also generate surprisingly high-resolution images, due to the way the photoreceptor cells deal with image movement.

Unlike the human lens, the insect eyes cannot move to accommodate different images. But the University of Sheffield researchers found that they do something else to compensate for that: underneath the lenses, photoreceptor cells move rapidly in and out of focus as they sample the world around them. This twitch-like movement is so fast that we can’t see it with the naked eye, and has long escaped detection from biologists. In order to thoroughly study it, researchers had to improvise a special microscope.

Researchers conducted in vivo electrophysiological measurements to understand how insects see. Image credits: Mikko Juusola et al — University of Sheffield.

A photoreceptor cell is a specialized type of cell found in the retina that absorbs light (photons). By triggering a change in the cell’s membrane potential, they transform this sensorial input into electrical signals which are then passed on to the brain. Compound eyes are better at detecting edges and are capable of forming images, but were thought to fare worse in terms of overall image quality. They still fare worse than human eyes, it’s just not as bad as we thought.

“By using electrophysiological, optical and behavioural assays with mathematical modelling we have demonstrated that fruit flies (Drosophila) have much better vision than scientists have believed for the past 100 years.”

If these findings are confirmed, then insects combine these normal head/eye movements with super-fast twitching to resolve the world in much finer detail. So far, this improved vision has only been detected in fruit flies (Drosophila), but researchers will soon move on to other insects, as well as vertebrates, in the hope of identifying similar patterns.

Mikko Juusola, Professor of Systems Neuroscience at the University of Sheffield and lead author of the study, said:

“From humans to insects, all animals with good vision, irrespective of their eye shape or design, see the world through fast saccadic eye movements and gaze fixations.It has long been known that fast visual adaptation results in the world around us fading from perception unless we move our eyes to cancel this effect. On the other hand, fast eye movements should blur vision which is why it has remained an enigma how photoreceptors work with eye movements to see the world clearly.”

“Our results show that by adapting the way photoreceptor cells sample light information to saccadic eye movements and gaze fixations, evolution has optimised the visual perception of animals. ”

The findings have been published in the open-access journal eLife.

Couple donates their $10 million insect collection to Arizona University

It’s a match made in heaven: boy loves girl, they roam the world searching for and studying insects. Now, some 60 years later, they’ve decided to donate their incredibly rich collection to further advance science.

Charlie O’Brien in his home office. The couple has spent decades traveling the world to study insects, which they now store in their home-made collection.
Photo by Deanna Dent/ASU Now

Lois and Charlie O’Brien are two retired entomologists who own one of the world’s most impressive insect collections — over ten million specimens, including more than a million weevils, known for almost destroying the cotton industry 100 years ago, and 250,000 planthoppers, the colorfully camouflaged bug that Lois prefers. Just look at how lovely she describes them:

‘They’re such wonderful creatures,’ she said. ‘Wouldn’t you like to fly? Wouldn’t you like to swim underwater for three days? Not to mention stinging. I have a neighbor I would like to sting.’ …

When Lois O’Brien met her future husband, she had a master’s degree in chemistry and was working part-time in the entomology department at the University of Arizona while she pursued a teaching degree. The entomology classes were so fascinating that she decided to switch fields.
Photo by Deanna Dent/ASU Now

But stinging neighbors aside, this collection can be a blessing for researchers. Aside from being a massive collection, some specimens are actually extremely impressive and have not been researched thoroughly. There are perhaps thousands of new species to science in their collection, which is now donated to Arizona State University.

The couple’s collection is one of the largest and most important private collections in the world.
Photo by Deanna Dent/ASU Now

“The specimens have a large reach in terms of their scientific visibility and ultimately their scientific impact for both research and mentoring, and that’s at the heart of what the O’Briens were looking for,” Nico Franz, an expert on the weevil and a long-time colleague of Charlie O’Brien said.

Charlie himself discovered and described hundreds of new weevil species, several of which have been named in his honor. He said they selected Arizona State University due to their upward trajectory in research funding and strong entomological base, which boasts an insect collection with almost 1 million specimens. The fact that Nico Franz, the curator of this collection, is good friends with Charlie likely also influenced the decision.

The weevils in the collection come in all colors and sizes, from all over the world.
Photo by Deanna Dent/ASU Now

Every specimen of the collection is worth $5 to $300, and the entire collection is estimated at $10 million, which is a massive donation — when you consider that the O’Briens also donated $2 million to help advance entomology research, the gesture becomes even more impressive.

“One of their unique features,” Franz said of the O’Briens, “is the combination of having amassed something of such great value and at the same time, sharing it so selflessly and widely.”

This is a life’s work they are donating. They used to work for 14 hours a day, seven days a week, traveling the world in search for new insects. Then they would spend months and months studying, classifying, and describing them. Now, they still work seven days a week, but mostly at home — pinning specimens in front of the TV.

Worm Meatball and Cricket Falafel — Researchers develop tasty food from yucky critters

When it comes to food, we tend to stick to what works — and for most of the world, insects are not on the menu. But in recent years, the idea of eating insects has gained traction across the world and some researchers argue that bugs can be a key part of a sustainable diet. For people who find it hard to go past the ‘yuck factor’, a team from the VTT Technical Research Centre of Finland has some good news: they’ve made tasty meatballs and falafel from crickets and worms.

VTT has developed raw materials from mealworms and crickets which, due to their promising structure and flavour, can be used in the manufacture of foods such as meatballs and falafel. Image credits: VTT

Crickets and worms are the most widely farmed insects in Western countries. I’ve had the chance to taste crickets and can say that they’re not nearly as bad as I would have imagined. A bit stale, but nothing a cold beer can’t wash down. Many other people are also starting to consider insects as a food source, but there’s a problem — people wouldn’t really like to cook insects, for obvious reasons. They also wouldn’t like it to come in a raw form and eat insects one by one. Most consumers would presumably like the food to come in a different form, something pre-cooked or pre-prepared to make it easier to digest (more mentally than physically). Ideally, something that people are already used to — and that’s what the VTT team went for.

They developed a dry fractionation method which separates insect fractions with varying flavors and degrees of coarseness. The finer fractions contain small amounts of the insect’s chitin shell which tend to be rough on the tongue and have a strong meat-like taste, while the coarse fractions have less flavor and more chitin. During the process, fat was also removed from the insects, leaving them with up to 65-80% crude protein.

Then, they figured that since insect fractions are very effective at binding things together, they might work well in things like meatballs or falafel. They replaced 5-18% of meatball or falafel dough with insect fractions, which doubled or even tripled the meal’s protein count. As for the taste? It was just as delicious as the original thing, or at least that’s what they tell us.

Several food manufacturers are already looking at ways through which insects can penetrate the food market. At the moment, insects have not been granted a novel food authorisation within the European Union, but such a decision is expected to come in 2018. In their basic form, insects are already available in some countries in Europe and eating them seems to have become somewhat of a trend. The United Nations promotes insect-eating as a sustainable approach which made them more popular, and it seems reasonable that more and more people will start eating the little critters — but if they could be incorporated into some processed foods, that would certainly help make them more palatable.

Still, there are also environmental concerns about eating insects. A 2016 PLOS study placed a question mark around the whole thing.

“I think the sustainability claims on this topic have been overstated given the current state of knowledge,” wrote study author Dr. Mark Lundy of the University of California Division of Agriculture and Natural Resources in an e-mail to Time.

So, where do you stand on this? Is eating insects OK? What about insect meatballs? The comment bar is your oyster!

Fossil Friday: the bug inside the lizard inside the snake

Forty-eight million years ago, a snake, a lizard, and an insect would unknowingly had a very, very bad day. But their Eocene tragedy would yield one of the most spectacular fossil finds of this year: the three animals fossilized together, one inside the other.

Yummy, yummy, get in my tummy. Forever!
Image credits Smith, K.T. & Scanferla A. / Palaeobio Palaeoenv (2016).

The fossil includes an unidentified insect ingested by a Geiseltaliellus maarius stem-basilisk (lizard,) which itself ended up as dinner for a juvenile Palaeopython fischeri snake. It was found in the Messel Pit, Germany, an area “renowned for the fidelity of preservation.” Today it’s a disused quarry but while these animals still lived, Messel was a volcanic lake with deep, toxic waters, and prone to belch out deadly clouds of carbon dioxide.

It’s unclear how the snake died, but no more than two days after eating the lizard it lay dead on the lake floor encased in fine sediment which would fossilize it, the lizard inside, and the insect inside both.

The fossil is the second of its kind ever found, and it preserves both the animals and a little piece of the day’s food chain. The other one was described in 2008 by a team led by the University of Vienna’s Jürgen Kriwet — it was a fossil of a shark that ate an amphibian with a spiny fish in its stomach.

It is, by all accounts, an astonishing find.

“It’s probably the kind of fossil that I will go the rest of my professional life without ever encountering again, such is the rarity of these things,” says Krister Smith, lead author of the paper describing the fossil.

“It was pure astonishment.”

The fossil will help define the range of Paleopython, which despite isn’t closely related to modern pythons.

“This fossil is amazing,” says Agustin Scafalera, co-author of the paper.

“We were lucky men to study this kind of specimen.”

Interpretive drawing of the fossil, overlaid on its photograph.
Image credits Smith, K.T. & Scanferla, A. / Palaeobio Palaeoenv (2016).

Maybe this is why my grandma told me not to swim after eating.

Amber reveals ancient insect that was literally scared out of its skin

Image credits George Poinar, Jr./Oregon State University

Image credits George Poinar, Jr./Oregon State University

It’s not uncommon for insects, plants and various other life forms to become trapped in amber deposits, but a recent discovery reveals a bit of a different story – a fifty-million-year-old exoskeleton of an ancient insect that was literally scared out of its skin.

The Baltic amber was retrieved from the coast of the Baltic Sea in Scandinavia and comes from a time when dinosaurs had recently died out and mammals were increasing in their diversity.

In addition to holding an insect exoskeleton, which is comparable to a modern-day “walking stick,” the amber also contains the first mushroom ever discovered in Baltic amber and a piece of mammalian hair. Taken together, these three remnants paint a picture of an ancient encounter between an insect and a rodent.

“From what we can see in this fossil, a tiny mushroom was bitten off, probably by a rodent, at the base of a tree,” said George Poinar, Jr., a researcher in in the College of Science at Oregon State University and author of the study. “An insect, similar to a walking stick, was probably also trying to feed on the mushroom. It appears to have immediately jumped out of its skin and escaped, just as tree sap flowed over the remaining exoskeleton and a hair left behind by the fleeing rodent.”

The ancient insect exoskeleton preserved in the amber was revealed to be a member of the Phasmatodea order, which are also referred to as stick insects due to their resemblance to sticks and leaves.

“It would have shed its skin repeatedly before reaching adulthood, in a short lifespan of a couple months,” Poinar said. “In this case, the ability to quickly get out of its skin, along with being smart enough to see a problem coming, saved its life.”

The presence of fine filaments in the exoskeleton suggest that the skin was extremely fresh when it was engulfed by the amber, supporting the idea that the insect jumped out of its skin just in the knick of time.

Journal Reference: A gilled mushroom, Gerontomyces lepidotus gen. et sp. nov. (Basidiomycota: Agaricales), in Baltic amber. 22 June 2016. 10.1016/j.funbio.2016.06.008

cyborg locust

Cyborg locusts might one day detect explosives and diseases

cyborg locust

Credit: BARANIDHARAN RAMAN

Why build some tech from scratch when nature did all the dirty work for you over millions of years of evolution? That was the thinking behind an innovative project led by Baranidharan Raman, associate professor of biomedical engineering in the School of Engineering and Applied Science Washington University, which aims to use microchip-enabled locusts to sniff out explosives. The project received a $750,000 grant from the US Office of Naval Research and, if found suitable, swarms of locusts could start sniffing for bombs as early as two years from now.

You might not have known this, but locusts have a very keen sense of smell. Each of their antennae is littered with hundreds of thousands of chemical sensors that convert odors into electrical signals, which are then transmitted to the circuits of neurons in the brain.

Previously, Raman and colleagues devised a set of experiments to see whether locusts could be Pavlovian conditioned — namely, to associate one particular stimulus that induces a specific response with a new stimulus. Russian physiologist Ivan Pavlov first demonstrated this form of conditioning in the 1890s in his famous experiments in which dogs were trained to associate the sound of a bell with food. In other words, a neutral stimulus introduced an automated response.

Using various odors, Raman coaxed his lab locusts to automatically respond to the stimuli with an average response time of 500 milliseconds. “The locusts robustly recognized and responded to the trained odor whether it was presented alone or after another odor, but their response time and behavior were less predictable when the trained odor followed a similar odor that evoked highly overlapping neural activity,” said Raman.

Now, a year later, Raman’s team wants to exploit this extraordinary sense of smell to sniff out bombs. Right now, dogs are employed throughout airports or border crossings to detect explosives, drugs or other illicit chemicals, owing to their remarkable sense of smell. But such dogs take years to train and can be in short supply. Locusts, on the other hand, could be just as good as dogs and might be bred by the thousands at a time.

“The canine olfactory system still remains the state-of-the-art sensing system for many engineering applications, including homeland security and medical diagnosis,” Raman said in a statement. “However, the difficulty and the time necessary to train and condition these animals, combined with lack of robust decoding procedures to extract the relevant chemical sending information from the biological systems, pose a significant challenge for wider application.

“We expect this work to develop and demonstrate a proof-of-concept, hybrid locust-based, chemical-sensing approach for explosive detection.”

To control the locusts, the researchers devised an interesting mind-control device. Heat generating “tattoos” would be placed on insect’s wings whose mild heat can be remotely triggered and control. This heat spurs the locusts to fly in a certain direction. Meanwhile, an on board low-power chip placed on the locust’s torso decodes any odor-related electrical signals sent by the antennae’s chemical sensors. This information is then quickly relayed to an authorized person through radio waves. A simple set of LED lights, then flashes: “red” for a bomb, “green” for all clear.

“Even the state-of-the-art miniaturised chemical-sensing devices have a handful of sensors. On the other hand, if you look at the insect antennae, where their chemical sensors are located, there are several hundreds of thousands of sensors and of a variety of types,” Raman told the BBC.

Raman estimates the first prototype might be ready for testing within a year. He also envisions his cyborg locusts sniffing all sorts of chemicals, besides bombs. For instance, these insects could be used in the medical sector to diagnose diseases. Dogs, for instance, have been shown to detect breast and lung cancers with an accuracy between 90 and 95 percent.