Half-a-million insect species face extinction: scientists

FEBRUARY 10, 2020

by Marlowe Hood

The disappearance of bugs that fly, crawl, burrow, jump and walk on water is part of a gathering mass extinction event

Half of the one million animal and plant species on Earth facing extinction are insects, and their disappearance could be catastrophic for humankind, scientists have said in a "warning to humanity".

"The current insect extinction crisis is deeply worrying," said Pedro Cardoso, a biologist at the Finnish Museum of Natural History and lead author of a review study published Monday.

"Yet, what we know is only the tip of the iceberg," he told AFP.

The disappearance of bugs that fly, crawl, burrow, jump and walk on water is part of a gathering mass extinction event, only the sixth in the last half-billion years.

The last one was 66 million years ago, when an errant space rock wiped out land-based dinosaurs and most other life forms.

This time we are to blame.

"Human activity is responsible for almost all insect population declines and extinctions," Cardoso told AFP.

The main drivers are dwindling and degraded habitat, followed by pollutants—especially insecticides—and invasive species.

Over-exploitation—more than 2,000 species of insects are part of the human diet—and climate change are also taking a toll.

The decline of butterflies, beetles, ants, bees, wasps, flies, crickets and dragonflies has consequences far beyond their own demise.

"With insect extinction, we lose much more than species," Cardoso said.

"Many insect species are vital providers of services that are irreplaceable," including pollination, nutrient cycling and pest control.

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Simulation explores how insects glean compass direction from skylight

JULY 18, 2019

by Public Library of Science

A computational simulation suggests that insects may be capable of using the properties of light from the sky to determine their compass direction with an error of less than two degrees. Evripidis Gkanias of the University of Edinburgh, U.K., and colleagues present their findings in PLOS Computational Biology.

Several insects, including honeybees, locusts, and monarch butterflies, use the position of the sun to guide their travel. Even when the sun is not visible, these insects can sense the polarization of light in the sky and use it to estimate the sun's position. However, the precise neural processes by which insects transform properties of light from the sky into an accurate compass sense are unclear.

To explore this question, Gkanias and colleagues built a computational simulation that incorporates a hypothetical system of neurons that an insect's brain could potentially use to reconstruct the sun's position from skylight properties detected by the eye. The simulation also incorporates known physical properties of light from the sky, the layout of the insect eye, and other biological parameters determined from previous research on the insect brain.

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Insects feel chronic pain after injury

JULY 11, 2019

by University of Sydney

Associate Professor Greg Neely and his team of pain researchers in the Charles Perkins Centre have found compelling evidence that insects feel persistent pain after injury.

Scientists have known insects experience something like pain since 2003, but new research published today from Associate Professor Greg Neely and colleagues at the University of Sydney proves for the first time that insects also experience chronic pain that lasts long after an initial injury has healed.

The study in the peer-reviewed journal Science Advances offers the first genetic evidence of what causes chronic pain in Drosophila (fruit flies) and there is good evidence that similar changes also drive chronic pain in humans. Ongoing research into these mechanisms could lead to the development of treatments that, for the first time, target the cause and not just the symptoms of chronic pain.

"If we can develop drugs or new stem cell therapies that can target and repair the underlying cause, instead of the symptoms, this might help a lot of people," said Associate Professor Neely, whose team of researchers is studying pain at the Charles Perkins Centre with the goal of developing non-opioid solutions for pain management.

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Insects have ‘no place to hide’ from climate change, study warns

Analysis of 50 years of UK data shows woodlands are not havens, while changing emergence times damage nature and farming

Damian Carrington Environment editor

Mon 1 Apr 2019 17.07 BSTLast modified on Mon 1 Apr 2019 20.40 BST

Insects have “no place to hide” from climate change, scientists have said after analysing 50 years’ worth of UK data.

The study found that woodlands, whose shade was expected to protect species from warming temperatures, are just as affected by climate change as open grasslands.

The research examined records of the first springtime flights of butterflies, moths and aphids and the first eggs of birds between 1965 and 2012. As average temperatures have risen, aphids are now emerging a month earlier, and birds are laying eggs a week earlier. The scientists said this could mean animals were becoming “out of sync” with their prey, with potentially serious ramifications for ecosystems.

Researchers are increasingly concerned about dramatic drops in populations of insects, which underpin much of nature. In February it was said that these falls could lead to a “catastrophic collapse of nature’s ecosystems”, and in March there was further evidence of widespread loss of pollinating insects in recent decades in Britain.

Other studies, from Germany and Puerto Rico, have shown falling numbers in the last 25 to 35 years. Another showed butterflies in the Netherlands had declined by at least 84% over the last 130 years.

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Plummeting insect numbers 'threaten collapse of nature'

Exclusive: Insects could vanish within a century at current rate of decline, says global review

Damian Carrington Environment editor

Sun 10 Feb 2019 18.00 GMTLast modified on Mon 11 Feb 2019 01.00 GMT

The world’s insects are hurtling down the path to extinction, threatening a “catastrophic collapse of nature’s ecosystems”, according to the first global scientific review.

More than 40% of insect species are declining and a third are endangered, the analysis found. The rate of extinction is eight times faster than that of mammals, birds and reptiles. The total mass of insects is falling by a precipitous 2.5% a year, according to the best data available, suggesting they could vanish within a century.

The planet is at the start of a sixth mass extinction in its history, with huge losses already reported in larger animals that are easier to study. But insects are by far the most varied and abundant animals, outweighing humanity by 17 times. They are “essential” for the proper functioning of all ecosystems, the researchers say, as food for other creatures, pollinators and recyclers of nutrients.

Insect population collapses have recently been reported in Germany and Puerto Rico, but the review strongly indicates the crisis is global. The researchers set out their conclusions in unusually forceful terms for a peer-reviewed scientific paper: “The [insect] trends confirm that the sixth major extinction event is profoundly impacting [on] life forms on our planet.

“Unless we change our ways of producing food, insects as a whole will go down the path of extinction in a few decades,” they write. “The repercussions this will have for the planet’s ecosystems are catastrophic to say the least.”

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Climate change on track to cause major insect wipeout, scientists warn

Insects are vital to ecosystems but will lose almost half their habitat under current climate projections

Damian Carrington Environment editor

Thu 17 May 2018 19.00 BSTLast modified on Fri 18 May 2018 00.55 BST

Global warming is on track to cause a major wipeout of insects, compounding already severe losses, according to a new analysis.

Insects are vital to most ecosystems and a widespread collapse would cause extremely far-reaching disruption to life on Earth, the scientists warn. Their research shows that, even with all the carbon cuts already pledged by nations so far, climate change would make almost half of insect habitat unsuitable by the end of the century, with pollinators like bees particularly affected.

However, if climate change could be limited to a temperature rise of 1.5C - the very ambitious goal included in the global Paris agreement - the losses of insects are far lower.

The new research is the most comprehensive to date, analysing the impact of different levels of climate change on the ranges of 115,000 species. It found plants are also heavily affected but that mammals and birds, which can more easily migrate as climate changes, suffered less.

“We showed insects are the most sensitive group,” said Prof Rachel Warren, at the University of East Anglia, who led the new work. “They are important because ecosystems cannot function without insects. They play an absolutely critical role in the food chain.”

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Unlocking the mystery of how insects got their wings

Hundreds of millions of years ago, two tissues fused to form wings on ancient beetles, according to the findings of a genetic experiment

Asher Elbein 

Beetle wings are often hidden. Nestled behind armoured shields on the beetle’s back, they unfurl in whirring sheets, whisking their clumsy owners from danger. Beetles don’t have more than two sets of wings – unless they’re in Yoshinori Tomoyasu’s lab.

In research recently published in the Proceedings of the National Academy of Sciences, Tomoyasu and his co-author, David Linz, genetically engineered beetle larvae with wings on their abdomens, part of an attempt to unpack one of evolution’s greatest mysteries: how insects gained the ability to fly.

Insects took to the empty skies sometime between 300 million and 360 million years ago, long before birds, bats or pterosaurs. Wings allowed them to conquer new habitats and ecological niches, and insecta quickly established themselves as one of the most diverse and successful animal classes, a position they still hold today.

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The disappearance of common species

Insect die-off: Even common species are becoming rare

Date:  February 1, 2018

Source:  Technical University of Munich (TUM)

Summary:

Scientists were able to show that currently widespread insects are threatened with a serious decline in species diversity in the near future. The research team lists fragmentation of habitats and intensification of agriculture as reasons for the decline of these 'generalists.'

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Encouraging insects back into arable land

In Sussex scientists have found that insecticide use has stabilised over the past two decades with an associated stabilisation of some insect groups, write Dr Julie Ewald and Prof John Holland of the Game & Wildlife Conservation Trust. Plus Judith Wright says we should let verges grow

Friday 20 October 2017 18.35 BSTLast modified on Friday 20 October 2017 22.00 BST

It is with great interest that we read about the long-term decline in the biomass of flying insects on German protected areas (Scientists tell of alarm at huge fall in flying insects, 19 October).

The Game & Wildlife Conservation Trust (GWCT) carries out two long-term surveys of insects on farmland in England – the Sussex Study (1970 to present) and at our demonstration farm in Loddington (1992 to present).

In the Sussex Study, which is one of the first Farmer Clusters in the country, over 100 cereal fields are sampled every year, which has revealed declines of 35% overall in the total number of invertebrates compared with the 87% decline in the biomass of flying insects found by Hallmann et al, with most of the decline in Sussex happening in the 1970s.

However, for insects that are chick-food for declining farmland birds, we found declines of up to 72% from 1970 to 2015, with 45% of invertebrate groups declining significantly.

Analysis on a field-by-field basis indicates that it is insecticide use that is responsible for lower insect numbers, especially those that provide food resources for declining farmland birds.

Read on  

Insects can see the world in much finer resolution than previously thought

September 5, 2017

Insects have much better vision and can see in far greater detail than previously thought, a new study from the University of Sheffield has revealed.

Scientists have long believed insects would not see fine images. This is because their compound eyes typically consist of thousands of tiny lens-capped 'eye-units', which together should capture a low-resolution pixelated image of the surrounding world.

In contrast, the human eye has a single lens, which slims and bulges as it focuses objects of interests on a retinal light-sensor (photoreceptor) array; the megapixel "camera chip" inside the eye. By actively changing the lens shape, or accommodating, an object can be kept in sharp focus, whether close or far away. As the lens in the human eye is quite large and the retinal photoreceptor array underneath it is densely-packed, the eye captures high-resolution images.

However, researchers from the University of Sheffield's Department of Biomedical Science with their Beijing, Cambridge and Lisbon collaborators have now discovered that insect compound eyes can also generate surprisingly high-resolution images, and that this has much to do with how the photoreceptor cells inside the compound eyes react to image motion.

Unlike in the human eye, the thousands of tiny lenses, which make the compound eye's characteristic net-like surface, do not move, or cannot accommodate. But the University of Sheffield researchers found that photoreceptor cells underneath the lenses, instead, move rapidly and automatically in and out of focus, as they sample an image of the world around them. This microscopic light-sensor "twitching" is so fast that we cannot see it with our naked eye. To record these movements inside intact insect eyes during light stimulation, the researcher had to build a bespoke microscope with a high-speed camera system.

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Six-legged livestock for sustainable food production

Sustainable food

Date: May 11, 2017

Source: Faculty of Science - University of Copenhagen

Identifying areas of particular high impact is an important step to improving the environmental sustainability of production systems. Insects have been heralded as the foods of the future -- and now the first study to measure the environmental impacts and identify hotspots associated with commercial insect production has been published.

Cricket farming can be a sustainable way to produce animal source foods

The study demonstrated that cricket farming can be a sustainable means of producing animal source foods. The study compared cricket production in Thailand to broiler chicken production. Fifteen different environmental impacts were investigated including global warming potential, resource depletion and eutrophication.

In most cases, cricket production had a lower impact than broiler chicken production. The major reason for the lower impacts is the fact that the feed conversion into animal protein is more efficient, as the production of the feed is a major hotspot in both systems.

"This research is very timely, as there are many different stakeholders interested in farmed insects. Many people have seen insects as a means of lowering the environmental burden of animal production. Insects, in many cases, can be comparable to meat and fish in terms of nutritional value. The fact that we have shown here that they can be produced more environmentally sustainably than meat means that they represent a massive potential for lowering the impact of the food production" explains lead author, PhD student Afton Halloran of the University of Copenhagen's Department of Nutrition, Exercise and Sports.

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Warming world harming insects' reproduction, says study

By Mark Kinver Environment reporter, BBC News

10 January 2017

A warming world harms insects' ability to reproduce, which could have long-term consequences, scientists warn.

UK researchers also found that insects in northern latitudes were more vulnerable than their southern-dwelling cousins.

The team added that many insects were unable to move great distances while they are juveniles. Therefore, they are at risk from a warming climate.

The findings have been published in the Journal of Evolutionary Biology.

"You get an extreme heat weather event that [the insect] cannot escape from because they are juveniles, so they can't move as much," explained co-author Rhonda Snook from the University of Sheffield, UK. 

"They live through it because it does not kill them, but then they have the subsequent problem of reproducing."

Lasting damage

Dr Snook said the insects in the team's experiments were exposed to a temperature increase of 5.5C (9.9F) for 10 days, which was enough to cause permanent damage to the insects' ability to reproduce.

She said the team was interested in studying the effect of temperature rises in organisms that were unable to move away from their immediate environment.

"Lots of insects in their juvenile stage can't move very far because they are larvae or because they are small nymphs - they are smaller and they do not have wings so they are not as mobile so they're stuck where they are."

Dr Snook told BBC News that the team carried out the experiments on fruit flies but she expected the results to be replicated in many other insects.

"I think that this is going to be a very common effect, a very common phenomenon across insects."

The team examined the effect of increased ambient temperature rise on two populations of fruit flies: one from Spain and another from Sweden.

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