Sioux Falls Zoologists endorse Life in the Undergrowth for showing
us the wide adaptability of insects to different environments.
Life in the Undergrowth
Life in the Undergrowth (2006) - 250 minutes
Life in the Undergrowth at Amazon.com
Hosted by David Attenborough
Open your eyes to the bizarre, ferocious and surprisingly beautiful world of the invertebrates. Join David Attenborough on his groundbreaking exploration into a spectacular miniature universe not normally seen, but teeming all around us. Within this remarkable world lie not just bugs and beetles, but exotic cicadas, neon glow worms, intricate silk-weaving spiders and bat-eating centipedes - not to mention a whole host of other incredible life-forms with intimate, startling behavior. Thanks to technical innovations in lighting, optics and computerized motion control, this turbulent, super-organized world is finally revealed from the perspective of its extraordinary inhabitants. These creatures may be minuscule, but they live life on a truly grand scale.
2-3-21 Some spiders use their silk to hoist helpless prey so it cannot escape
Some spiders take on prey that is far larger than they are, including lizards. To stop such prey from running away, they use their webs as pulleys to lift the doomed animals off the ground. Gabriele Greco and Nicola Pugno at the University of Trento in Italy used high-speed video to watch five captive spiders from the Theridiidae family catch cockroaches up to 50 times more massive than themselves. These are the most common type of spider found in human homes. The researchers found that the spiders seemed to be using their body weight to put tension on the silk threads to keep them taut before attaching them to the cockroaches. The spiders then continued to attach more and more threads to their prey until it was lifted into the air. “In the end, all these threads create enough tension to lift the prey, and that is when the spider wins,” says Greco. “Then the prey cannot escape because it cannot grab the surface below.” Once the prey is off the ground and unable to run away, the spider can take its time to kill and devour it. The researchers found that the silk didn’t stretch much during lifting, possibly because the spiders had already stretched it out before attaching it to their prey. This allowed the threads to recover when the cockroaches struggled instead of permanently sagging. “This silk used to lift the prey, it’s very strong, comparable to steel, but it is as elastic as the normal silk you would use to make clothes,” says Greco. This is interesting because you might not expect such a relatively simple animal to know how to use tools to catch its prey in such a sophisticated way, he says. It may allow spiders to have an outsized impact on their ecosystems by eating all sorts of small animals instead of just bugs.
9-29-20 Invasive jumping worms damage U.S. soil and threaten forests
The writhing wrigglers devour leaf litter, changing soils and ecosystems as they go. What could be more 2020 than an ongoing invasion of jumping worms? These earthworms are wriggling their way across the United States, voraciously devouring protective forest leaf litter and leaving behind bare, denuded soil. They displace other earthworms, centipedes, salamanders and ground-nesting birds, and disrupt forest food chains. They can invade more than five hectares in a single year, changing soil chemistry and microbial communities as they go, new research shows. And they don’t even need mates to reproduce. Endemic to Japan and the Korean Peninsula, three invasive species of these worms — Amynthas agrestis, A. tokioensis and Metaphire hilgendorfi — have been in the United States for over a century. But just in the past 15 years, they’ve begun to spread widely (SNS: 10/7/16). Collectively known as Asian jumping worms, crazy worms, snake worms or Alabama jumpers, they’ve become well established across the South and Mid-Atlantic and have reached parts of the Northeast, Upper Midwest and West. Jumping worms are often sold as compost worms or fishing bait. And that, says soil ecologist Nick Henshue of the University at Buffalo in New York, is partially how they’re spreading (SN: 11/5/17). Fishers like them because the worms wriggle and thrash like angry snakes, which lures fish, says Henshue. They’re also marketed as compost worms because they gobble up food scraps far faster than other earthworms, such as nightcrawlers and other Lumbricus species.But when it comes to ecology, the worms have more worrisome traits. Their egg cases, or cocoons, are so small that they can easily hitch a ride on a hiker’s or gardener’s shoe, or can be transported in mulch, compost or shared plants. Hundreds can exist within a square meter of ground.
6-27-20 How one teaspoon of Amazon soil teems with fungal life
A teaspoon of soil from the Amazon contains as many as 1,800 microscopic life forms, of which 400 are fungi. Largely invisible and hidden underground, the "dark matter" of life on Earth has "amazing properties", which we're just starting to explore, say scientists. The vast majority of the estimated 3.8 million fungi in the world have yet to be formally classified. Yet, fungi are surprisingly abundant in soil from Brazil's Amazon rainforest. To help protect the Amazon rainforest, which is being lost at an ever-faster rate, it is essential to understand the role of fungi, said a team of researchers led by Prof Alexandre Antonelli, director of science at the Royal Botanic Gardens, Kew. "Take a teaspoon of soil and you will find hundreds or thousands of species," he said. "Fungi are the next frontier of biodiversity science." Fungi are usually neglected in inventories of biodiversity, being inconspicuous and largely hidden underground. Fewer than 100 types of fungi have been evaluated for the IUCN Red List, compared with more than 25,000 plants and 68,000 animals. Fungi in soil from tropical countries are particularly poorly understood. To find out about soil from the Amazon rainforest in Brazil, researchers collected samples of soil and leaf litter from four regions. Genetic analysis revealed hundreds of different fungi, including lichen, fungi living on the roots of plants, and fungal pathogens, most of which are unknown or extremely rare. Most species have yet to be named and investigated. Areas of naturally open grasslands, known as campinas, were found to be the richest habitat for fungi overall, where they may help the poorer soil take up nutrients. Understanding soil diversity is critical in conservation actions to preserve the world's most diverse forest in a changing world, said Dr Camila Ritter of the University of Duisburg-Essen in Germany. "For this, we need to put below-ground biodiversity on the agenda for future conservation action plans," she said.
4-24-20 The ‘insect apocalypse’ is more complicated than it sounds
Freshwater arthropods trended upward, while terrestrial ones declined, decades of data suggest. Taking a big view of the so-called Insect Apocalypse finds some possible winners among the losers, plus a lot of things we don’t know yet. Overheated end-times terms have popped up during the last few years conveying fear that the bounty of Earth’s butterflies, beetles, bees and many other insects has started slipping away. The worry is not just about species likely to go extinct. Even species that will probably survive might be shrinking in population so much that their skimpy numbers no can longer fill their current roles in ecosystems. Now a new look at insect abundance, slanted toward North America and Europe, hints that freshwater residents are overall increasing. Data mostly gathered since the 1960s suggests that beetles, mayflies, dragonflies and other creatures that spend a good part of their lives in water have increased about 11 percent per decade, says a study in Science April 24. In contrast, land-dwelling insects shrank in abundance by about 9 percent per decade, the study says. “Insects will not disappear,” says coauthor Roel van Klink, an entomologist at the German Center for Integrative Biodiversity Research in Leipzig. He and colleagues found, however, “a lot of reason for concern” overall, he says. Van Klink first started thinking about the project in 2017, when careful, long-term monitoring of the biomass of insects flying in 63 protected nature preserves in Germany had dropped more than 75 percent over 27 years. “I doubt that’s a general phenomenon,” van Klink remembers thinking. After two months without hearing about anybody else starting a worldwide search for data, he says he realized, “I’ve got do it.” Van Klink and colleagues found 166 surveys of abundance (numbers of individuals and/or the absolute mass of insects and occasionally spiders mixed in) that ran for at least 10 years at 1,676 sites around the world. The oldest data went back to 1928, but data are most abundant from the 1980s. Researchers compared how steeply or gently the populations were falling and rising. Many of the sites already were affected heavily by humans when surveys began. For instance, he speculates that the rise in freshwater arthropod abundance may reflect some recovery as environmental laws improved water quality in the United States.
4-23-20 Reports of an insect apocalypse are overblown but still concerning
Reports of the death of insects may have been greatly exaggerated. Research out today finds that while an alarming 9 per cent of land-dwelling insects are being lost each decade, the state of the world’s insects is much more nuanced than warnings of an “insect apocalypse”. The issue came to the fore in 2017, when a study found a 75 per cent decline in flying insects across parts of Germany due to environmental pressures such as intensive farming. But fears of an insect meltdown – and the impact on the food we all rely on – really took off last year with a study by Francisco Sánchez-Bayo at the University of Sydney and his colleagues that hit front pages suggesting 2.5 per cent of insect biomass is being lost each year. Without action, the team cautioned: “Insects as a whole will go down the path of extinction in a few decades.” A backlash ensued, with at least seven criticisms published in journals. A simple one was the authors had conducted keyword searches of literature for the “insect” and “decline”, but not for “increase”, which would bias their literature review. So what is the true state of the world’s insects? Entomologists say a new analysis published in the journal Science today gives a much more realistic, but no less concerning, picture. Roel van Klink at the German Centre for Integrative Biodiversity Research in Leipzig and his colleagues compiled data on the long-term abundance of thousands of insect species from 166 studies in 41 countries, covering declines and increases. Gergana Daskalova at the University of Edinburgh, UK, who was not involved in the study, says it is the most comprehensive to date. The analysis concluded that the number and biomass of insects is declining at 0.92 per cent a year. While much lower than the number in last year’s paper, van Klink notes that out over the course of a human generation, or 30 years, it is a decline of a quarter. “I find that quite severe and quite alarming,” he says. “The most important thing for people to realise is it’s not going bad for insects everywhere, that it’s variable.”
4-23-20 Nature crisis: 'Insect apocalypse' more complicated than thought
The global health of insect populations is far more complicated than previously thought, new data suggests. Previous research indicated an alarming decline in numbers in all parts of world, with losses of up to 25% per decade. This new study, the largest carried out to date, says the picture is more complex and varied. Land-dwelling insects are definitely declining the authors say, while bugs living in freshwater are increasing. Reports of the rapid and widespread decline of insects globally have caused great worry to scientists. The creatures are among the most abundant and diverse species on the planet and play key roles, from aerating the soil to pollination and recycling of nutrients. Case studies, such as one from nature reserves in western Germany, indicated a dramatic fall, with around a 75% decrease over 27 years. Many other, similar reports have followed. But many of these were specific to a region or a species. This new study, the largest on insect change to date, aims to give a more complete understanding of what's really happening to bugs worldwide. Drawing on data from 166 long-term surveys across 1,676 sites, it paints a highly nuanced and variable picture of the state of insect health. The compilation indicates that insects like butterflies, ants and grasshoppers are going down by 0.92% per year, which amounts to 9% per decade, lower than many published rates. This is not as bad as previous reports but the authors stress that it is still substantial. "That is extremely serious, over 30 years it means a quarter less insects," said lead author Dr Roel Van Klink, from the German Centre for Integrative Biodiversity Research. "And because it's a mean, there are places where it is much worse than that." Many people have an instinctive perception that insects are decreasing - often informed by the so-called "windscreen phenomenon", where you find fewer dead bugs splattered on cars. The researchers say it's real.
2-7-20 Fireflies face extinction risk - and tourists are partly to blame
Firefly tourism is on the rise globally but scientists are warning it may contribute to risk of the insect's extinction. "I spotted a hundred flickering lights, illuminating a palm like a Christmas tree." "Our guide waved his flashlight at the fireflies. They slowly engulfed us - we were surrounded by a shiny galaxy of glowing beetle stomachs." "I reached out a hand and captured one in my fist." Reading this travel blogger's enchanting experience in 2019 makes it clear why firefly tours are popular, but done badly, it risks killing the insects. Habitat loss and light pollution from urbanisation and industrialisation are the leading threats to firefly populations, according to research published this week. But firefly tourism, which attracts thousands of visitors in countries including Mexico, the US, the Philippines and Thailand, is a growing concern for conservationists. "Getting out into the night and enjoying fireflies in their natural habitat is an awe-inspiring experience," Prof Sara Lewis at Tufts University, who led the research, told the BBC. But tourists often inadvertently kill fireflies by stepping on them, or disturb their habitat by shining lights and causing soil erosion. Firefly festivals are organised in countries including Japan, Belgium, and India, and social media is magnifying this tourism, she adds. The tiny town of Nanacamilpa in Mexico became a celebrated firefly spot in the past decade. Some visitors post their sparkling photos on Instagram, flouting the ban on photography that many site managers impose, says local photographer Pedro Berruecos. The Mexican fireflies are especially vulnerable to tourists, Prof Lewis explains. The female insects are wingless and cannot fly, meaning they live on the ground, where visitors walking around will trample on them.
7-7-19 Obituary: Georges Brossard, the man who stuck up for insects
Georges Brossard dedicated his life to helping humans appreciate the underappreciated world of insects. Brossard, who has died aged 79, gave up a career in law to travel the world and collect more than 250,000 specimens, a collection that would eventually become one of Montreal's most visited tourist attractions. He inspired millions through regular TV appearances, raising the profile of tiny creatures he believed were misunderstood and undervalued in human society. One particular journey to find a rare insect - an extraordinary trip into the Mexican rainforest - would go on to inspire a film. Georges Brossard was born in 1940 into a farming family in La Prairie, Quebec. His father, Georges-Henri, founded the nearby city of Brossard, on Montreal's South Shore. In a 1989 interview he described the La Prairie of his childhood as "a beautiful, unspoiled place" and recalled how a school science class inspired him to start his first collection of insects. "In a cupboard at school there were two specimens for our science class, a butterfly and a chunk of asbestos," he said. "I could gaze at them for hours. I guess that's when I became attracted to insects." Even the destruction of that early collection - by ants and spiders - only inspired him to greater things. "When I saw my collection in ruins like that, it hit me like a bolt of lighting. I knew that eventually I would be a great international collector. I saw my insectarium. I saw myself standing there explaining the world of insects to people," he said. His plan took a while to come fruition. Brossard went on to study law at the University of Ottawa and became a notary - an official witness to the signing of contracts, agreements and other legal documents. But by his late 30s he had decided to devote his career to his great passions - entomology and the environment.
5-14-19 Peacock spiders’ superblack spots reflect just 0.5 percent of light
New images reveal microscopic structures that manipulate light to create the dark patches. Male peacock spiders know how to put on a show for potential mates, with dancing and a bit of optical trickery. Microscopic bumps on the arachnids’ exoskeletons make velvety black areas look darker than a typical black by manipulating light. This architecture reflects less than 0.5 percent of light, researchers report May 15 in the Proceedings of the Royal Society B. The ultradark spots, found near vivid colors on the spiders’ abdomens, create an “optical illusion that the colors are so bright … they're practically glowing,” says Harvard University evolutionary biologist Dakota McCoy. Male peacock spiders swing and shake their brilliantly colored abdomens during elaborate mating displays. Pigments produce the red and yellow hues, but blues and purples come from light interacting with hairlike scales (SN: 09/17/16, p. 32). Black areas on the spiders contain pigment, too. But scanning electron microscopy also revealed a landscape of tiny bumps in superblack patches on Maratus speciosus and M. karrie peacock spiders. In contrast, all-black, closely related Cylistella spiders have a smooth texture. Scanning electron microscope images show bumps, which manipulate incoming light, in superblack patches on the abdomens of two species of peacock spiders. While Maratus speciosus (left) has only bumps, M. karrie (middle) also sports spiky scales that limit reflection by scattering and absorbing light. A Cylistella spider (right) has a smoother surface, which results in an ordinary black appearance.
11-22-18 Sick ants stay clear of their co-workers to stop disease spreading
Do you wish your coughing, sneezing colleagues would stay away from the office? Unlike some humans, ants seem to understand the importance of avoiding others when they are infected. When foraging ants are exposed to a fungal pathogen, they reduce their contact with workers inside the nest. Nathalie Stroeymeyt at the University of Lausanne, Switzerland, and colleagues studied colonies of Lasius niger ants using an automated ant-tracking system. Workers in these colonies are split into nurses, which work inside the nest caring for the brood, and foragers, which collect food outside the nest. Foragers are most likely to pick up infections, but they interact less with other ants, and come into contact with those inside the nest infrequently. The researchers exposed some of the foragers to spores of Metarhizium brunneum fungus. The spores attach to an ant’s cuticle and after a day or two, the fungus gets inside the ant and kills it. Within one day of exposure to the pathogen — before ants became sick — the separation between work groups was reinforced. Exposed foragers changed their behaviour, spending even more time outside the nest and decreasing their contact with other workers. Foragers that were not exposed to the pathogen also took steps to isolate themselves, and nurses moved the brood deeper inside the nest. It’s not clear how the ants recognise the infection, but they may be able to detect the spores on other ants as well as on their own bodies.
8-20-18 Ants show 'lazy' approach may be best for digging
A new study on ants and robots has shown that having more workers is not necessarily better when working in confined spaces. If there are too many bodies then the workspace can get clogged. A less busy approach in which some workers are purposely idle can avoid jams. The findings might help devise strategies to avoid clumping in confined and crowded environments, such as disaster relief operations. The research has been published in the journal Science. Prof Daniel Goldman, a physicist and robotics expert at Georgia Institute of Technology, has been studying invasive fire ants for eight years, since he realised that understanding how they cooperate to dig tunnels could have real-life consequences for robot design. The new study has shown that sometimes a laid back approach can get the job done. Unlike cars that clump together or buses that arrive at the same time, ants rarely seem to have traffic jams. Prof Goldman said: "We painted the abdomens of ants with oil-based markers and by monitoring which ants showed up in the tunnel, we found that in fact about 30% of the ants in a group did about 70% of the work, because they came to the tunnel more often and they excavated more pellets." He added: "We wanted to know why only about 30% of ants were excavating, and to understand how basic laws of physics might be at work." It turned out that the inequality in ant labour is not because the hardest working individuals have a specialist "qualification" in tunnel engineering.
8-16-18 Future robot swarms should copy lazy ants who let others do the work
The optimum strategy for tunnelling ants is to leave all of the digging to just a few workers. Swarms of robots could use similar techniques for clearing rubble. Too many cooks spoil the broth, and the same goes for ants. A study into how ants cooperate has found that the optimum strategy is for most of them not to do any work. The findings may be useful for creating large swarms of robots. Ants create networks of narrow underground tunnels by excavating soil bit by bit as a team. To understand the strategies they use, Daniel Goldman at Georgia Tech and his colleagues placed 30 ants into a transparent container filled with glass soil-like particles. For 48 hours ants entered and exited the tunnels hundreds of times to extend the network, but surprisingly only 30 per cent of the ants did around 70 per cent of the work. “Only a few ants would do the majority of the work, with the rest just hanging out trying to avoid clogging up the tunnel,” says Goldman. To further understand the process, Goldman and his colleagues tested out different strategies with four excavation robots. “One dug OK. Two dug OK. Three was kind of good. But with four the robots just couldn’t get anywhere,” says Goldman. However smart his team made the robots they kept causing clogs unless some took a back seat. The results suggest when groups of individuals work together, the best strategy may be for some to hang back, he says. The work can help uncover some of the strategies that biological organisms have evolved to use, but may also help write better software for controlling swarms of robots.
8-16-18 Here’s what robots could learn from fire ants
In tight quarters, sharing the work equally leads to traffic jams. Robots, take note: When working in tight, crowded spaces, fire ants know how to avoid too many cooks in the kitchen. Observations of fire ants digging an underground nest reveal that a few industrious ants do most of the work while others dawdle. Computer simulations confirm that, while this strategy may not be the fairest, it is the most efficient because it helps reduce overcrowding in tunnels that would gum up the works. Following fire ants’ example could help robot squads work together more efficiently, researchers report in the Aug. 17 Science. Robots that can work in close, crowded quarters without tripping each other up may be especially good at digging through rubble for search-and-rescue missions, disaster cleanup or construction, says Justin Werfel, a collective behavior researcher at Harvard University who has designed insect-inspired robot swarms (SN: 3/22/14, p. 8).
6-21-18 Moths fly 1000 kilometres with Earth’s magnetic field as a guide
Bogong moths are the first insects found to use Earth’s magnetic field to navigate long distances, during their epic migrations across Australia. An Australian moth uses the Earth’s magnetic field to help find its way across the continent. While other insects have been shown to navigate using Earth’s magnetic field, the moth is the first to do so over long distances and at night. Bogong moths (Agrotis infusa), like the famous monarch butterflies in the Americas, make an epic migration. In spring, about 2 billion of them leave their breeding grounds on the dry, flat plains of south-east Australia, and fly over 1000 kilometres to a set of around 50 caves high in the Australian Alps. There they spend the summer, dormant. In autumn, they return to the plains where they reproduce and die. Eric Warrant of the University of Lund, Sweden and his colleagues studied how the moths find their way. “When we began this study, we were convinced that the bogong moth would exclusively use celestial cues in the sky, such as the stars and the moon, for navigation during migration,” he says. But that is not what they found. The team trapped wild moths and placed them one at a time in a flight simulator where they could watch them closely. The simulator was completely blank inside except for two simple landmarks, and it was fitted with magnetic coils so the team could manipulate the magnetic field within. If the visual and magnetic cues both directed the moths to fly a particular direction, they did so. “They love the pretend mountain landmark, and love to fly towards it,” says Warrant.
3-27-18 Beetlemania: How a supergroup scuttled to world domination
Handsome, hardy and diverse, beetles are supremely successful critters with a lot to teach us – but they’re suffering from our environmental waywardness. WHEN biologist J.B.S. Haldane was asked by a theologian back in the 1940s what we could infer about the mind of the creator from the works of creation, he supposedly replied, “an inordinate fondness for beetles”. The story is almost certainly apocryphal, but it reveals both an undeniable truth and an open question. Judging by their sheer numbers, God is certainly fond of beetles. But just how fond? The number of beetle species is just one lacuna in our knowledge of these extraordinarily successful creatures. Another is what makes them quite so successful. As we slowly fill in the gaps, we are beginning to appreciate the unique insights these insects can give us. Whether we want to understand evolution, the workings of the biosphere or how plate tectonics has shaped the continents, beetles hold the answers. But let’s deal with the numbers question first. New beetle species have been described at an average rate of about four a day since 1758, when Carl Linnaeus started cataloguing plants and animals using the two-part Latin scientific names we know today. Towards the end of the 20th century, there was general agreement that the total count was heading towards 400,000 species, based on specimens housed in the world’s museums and carefully documented in 250 years of scientific journals and monographs. Compare that with 5500 mammals, 10,000 birds, 85,000 molluscs and 250,000 plant species, and it is clear that in diversity beetles far outstrip any other multicellular organisms, perhaps quietly brushing aside nematode worms.
3-27-18 Beetlemania: Five amazing beetles from around the world
Whether it is harvesting water, doing origami or hitching free rides on termite backs, the sheer diversity of beetle behaviour is the key to their success.
- Head-stander beetles
- Hazel leaf-roller
- Giraffe weevil
- American burying beetle
- [No common name]
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Life in the Undergrowth
Sioux Falls Zoologists endorse Life in the Undergrowth for showing
us the wide adaptability of insects to different environments.