How do flightless stick insects spread their populations?

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10-10-2023

Eric Ralls

ByEric Ralls

Earth.com staff writer

In the diverse world of entomology, stick insects stand out for a peculiar reason — their apparent ability to span vast distances despite being flightless. Their widespread presence across geographical barriers that would be daunting for most flightless species has long been a conundrum.

However, a new study led by Kobe University has shed light on this puzzle, pointing to a surprising ally in their dispersal: birds.

The stick insect dispersal enigma

The majority of stick insect species lack wings, making their extensive distribution across various terrains seem perplexing. This anomaly led to the hypothesis that their eggs might be dispersed by birds, mirroring the method many plants utilize.

The concept is simple: birds consume fruits, and the seeds within pass through their digestive systems, emerging unharmed and often at great distances from their origin.

In an experimental setting, studies focusing on Ramulus mikado, a common Japanese stick insect, confirmed that such a dispersal mechanism could indeed be possible. Yet, without any direct observation in the wild, doubt lingered about its real-world applicability.

Genetic evidence from stick insects

To address this gap, biologist Suetsugu Kenji from Kobe University and his team embarked on an ambitious project. They analyzed genetic patterns in Ramulus mikado populations, leveraging the principle of “genetic isolation by geographic distance.”

This theory posits that in species with limited mobility, genetic mutations accumulate over time, leading to a correlation between genetic differentiation and geographical distance.

Their findings, published in the Proceedings of the Royal Society B, were astonishing. While many genes showed predictable differences based on geographic distance, a select few exhibited close relations despite being separated by vast distances and formidable geographical barriers.

Kenji Suetsugu, the lead author, remarked, “Amidst a sea of limited active dispersal, we discovered identical genotypes jumping across vast distances, strongly indicating the past occurrence of passive long-distance genetic dispersal.” This discovery implies that these flightless insects may have, indirectly, taken to the skies through avian digestive systems.

Unique reproductive mechanism

This begs the question: why is such a dispersal mechanism not more prevalent among other insects? The answer lies in the unique reproductive nature of some stick insect species.

Most insect eggs are fertilized shortly before they are laid. However, certain stick insect species exhibit parthenogenesis, allowing females to produce viable eggs without fertilization. This reproductive peculiarity ensures the survival of stick insect offspring even when they embark on such perilous journeys.

Ironically, stick insects have earned their name due to their primary survival strategy: blending in with their environment to avoid predators. This is starkly different from plants that rely on their seeds being consumed and dispersed.

Implications and future research

The ramifications of this study extend beyond the life cycle of stick insects. Kenji Suetsugu emphasizes the broader significance of their findings, stating, “This result invites researchers to delve deeper into the mechanisms of dispersal in various species and challenge long-held assumptions about the fate of organisms devoured by predators.”

This intriguing research underscores the intricate and often unexpected relationships that govern the natural world. As scientists continue to unravel these complexities, we are reminded of nature’s ingenuity and resilience in the face of challenges.

More about stick insects

Stick insects, often referred to as walking sticks, are nature’s true masters of camouflage. Belonging to the Phasmatodea order, these insects stand out for their remarkable ability to blend seamlessly into their surroundings.

Habitat

Native to various parts of the world, stick insects primarily inhabit tropical and subtropical rainforests. However, some species thrive in temperate regions as well. They owe their name to their uncanny resemblance to twigs, branches, or leaves, a disguise they expertly employ to evade predators.

Diet

Most stick insects showcase a predominantly herbivorous diet. They feed on leaves, favoring particular plants depending on the species. Their feeding habits often lead them to play vital roles in controlling vegetation and contributing to their ecosystem’s health.

Reproduction

One of the most intriguing aspects of stick insects is their reproductive versatility. While many species mate conventionally, some exhibit a unique phenomenon called parthenogenesis. In this process, females produce viable eggs without needing to mate with males, allowing rapid reproduction when necessary.

Defense mechanisms

In defense, besides camouflage, stick insects employ other tactics. When threatened, some species play dead, dropping to the ground and remaining motionless. Others might release a foul-smelling substance or make hissing sounds by rubbing their body parts together.

Kept as pets

For those keen on keeping exotic pets, stick insects make an interesting choice. They require a relatively simple habitat setup, often just a ventilated cage with appropriate foliage and regular misting. Their docile nature and easy care make them ideal for enthusiasts of all ages.

In summary, stick insects are a captivating group of creatures. Their unparalleled camouflage abilities, diverse habitats, and unique reproductive strategies make them an endless source of fascination for both scientists and nature enthusiasts alike.

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Microbial Allies May Help Turn Tables on Tar Spot Fungus in Corn

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Microbial Allies May Help Turn Tables on Tar Spot Fungus in Corn

Wednesday, 25 October 2023 09:47:07

Grahame Jackson posted a new submission ‘Microbial Allies May Help Turn Tables on Tar Spot Fungus in Corn’

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Microbial Allies May Help Turn Tables on Tar Spot Fungus in Corn

USDA-ARS
https://content.govdelivery.com/accounts/USDAARS/bulletins/3767235

For media enquiries, Jan Suszkiw Agricultural Research Service (ARS) scientists are leaving no stone—or rather, leaf—unturned in their search for new ways to counter the fungus that causes tar spot, a yield-robbing disease of field corn in the midwestern United States. First reported in Illinois and Indiana in 2015, tar spot has now expanded to include other nearby states, as well as Florida and Canada. The disease manifests as raised black spots that mottle the leaves, husks and stalks of susceptible corn varieties, diminishing their photosynthetic ability and, in severe cases, killing the plants and inflicting grain yield losses of 20 to 60 bushels an acre. Now, however, those same spots may reveal a hidden foe of the fungus that causes tar spot, Phyllachora maydis. The spots, called stromata, are a tough, structural form of the fungus that enables it to survive the winter and release a bevy of spores the following spring that infect the next corn crop. But a team of sharp-eyed scientists with ARS’s National Center for Agricultural Utilization Research in Peoria, Illinois, observed that some stromata specimens they collected failed to germinate—the “handiwork” of other fungi and bacteria that parasitize the tar spot fungus, potentially opening the door to a biologically based approach to controlling it. The scientists’ observation came while inspecting a research plot of corn near the ARS center in April 2022. Mild outbreaks of tar spot can generally be reduced with synthetic fungicide applications and corn varieties that can tolerate some damage from the fungus. But under the right weather conditions, severe outbreaks can overwhelm these defenses, exacting a costly toll on farmer profits and underscoring the need for additional countermeasures that can be deployed.  Fortunately, nature, with its system of checks and balances, offered several different species of fungi and bacteria that grow and reproduce on or inside the fungus’s stromata—some of which appeared as a whitish fuzz on the stromata when researchers examined them under a microscope in the laboratory. The researchers’ use of DNA-based identification methods revealed that some of the fungi and bacteria were known biological control agents of diseases affecting other crops.  In trials, for example, exposure to spores of Gliocladium catenulatum (a commercially available biocontrol fungus) prevented 88 percent of the tar spot fungus’ stromata from germinating. An Alternaria fungus isolated from a tar spot stroma prevented about 45 percent of stromata from germinating. Several research studies have demonstrated that some strains of Alternaria alternataare effective biocontrol organisms that can reduce the damage caused by plant pathogens, said Eric Johnson, a research molecular biologist with the ARS center’s Crop Bioprotection Research Unit in Peoria. Additionally, laboratory assays indicated that the Alternaria strain tested did not cause disease in a susceptible variety of corn when added to damaged portions of leaves. It may be additionally useful in killing overwintering tar spot stromata given that the tested strain grew well at cold temperatures, Johnson added. The scientists’ studies are in the early stages and more research will be necessary to fully ascertain the fungi and bacteria’s potential to biologically control tar spot in commercial fields when applied during the growing season or to kill overwintering. In the meantime, other approaches for managing the disease are also being explored, both in Peoria and at ARS’s Crop Production and Pest Control Research Unit in West Lafayette, Indiana. These include: Examining the basic biology and genetic underpinnings of the tar spot fungus for clues to new ways of controlling it. Developing molecular markers to speed the search for new sources of tar spot resistance in corn. Exploring strategies to make better use of fungicides registered for use against tar spot in corn as part of an integrated approach to managing the disease. Details on the biocontrol potential of the tar spot fungus’s natural rivals were published in the June 2023 issue of the journal Microorganisms by Johnson and co-authors Pat DowdJose Ramirez and Robert Behle—all with the ARS center’s Crop Bioprotection Research Unit in Peoria.  Additional research on biological control of tar spot disease in Peoria is now being funded by the Illinois Corn Growers Association and ARS National Plant Disease Recovery System. The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in U.S. agricultural research results in $20 of economic impact.

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Tree-planting schemes threaten tropical biodiversity

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Tree-planting schemes threaten tropical biodiversity

This article is more than 1 month old

Paper reveals scientists’ concerns that single-species carbon plantations threaten native flora and fauna, while delivering negligible benefits

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Patrick Greenfield

@pgreenfieldukTue 3 Oct 2023 11.00 EDT

Monoculture tree-planting schemes are threatening tropical biodiversity while only offering modest climate benefit, ecologists have said, warning that ecosystems like the Amazon and Congo basin are being reduced to their carbon value.

Amid a boom in the planting of single-species plantations to capture carbon, scientists have urged governments to prioritise the conservation and restoration of native forests over commercial monocultures, and cautioned that planting swathes of non-native trees in tropical regions threatens important flora and fauna for a negligible climate impact.

Writing in the journal Trends in Ecology & Evolution, ecologists said the increasing popularity of commercial pine, eucalyptus and teak plantations in the tropics for carbon offsetting is having unintended consequences, such as drying out native ecosystems, acidifying soils, crowding out native plants and turbocharging wildfires.

“Despite the broad range of ecosystem functions and services provided by tropical ecosystems, society has reduced the value of these ecosystems to just one metric – carbon,” the paper reads. “It is broadly assumed that maximising standing carbon stocks also benefits biodiversity, ecosystem function and enhances socioeconomic co-benefits – yet this is often not the case.”

Tree-planting has been held up as an important tool in mitigating global heating, with dozens of public and private initiatives under way to rapidly increase forest cover around the world to meet net zero goals. However, research indicates that the environmental benefit is heavily dependent on the scale and type of restoration, and requires huge areas of land. One 2019 study estimated that allowing natural forests to regenerate could return 40 times as much carbon as plantations.

Jesús Aguirre-Gutiérrez, an ecologist at the University of Oxford who led the paper, said the scientists decided to say something after witnessing the increase in commercial plantations in the tropics.

Photo taken in August 2019 shows a destroyed eucalyptus plantation after fire in Humaita, Amazonas, Brazil.
‘Tree-planting should not be seen as an alternative to rapidly cutting fossil fuel emissions,’ said Simon Lewis from University College London. Photograph: Gabriela Biro/Alamy

“We carry out a lot of fieldwork in the tropics to research what is happening with climate change and we have seen the boom in these plantations for ourselves: teaks, conifer and eucalyptus, just one or two species,” he said. “These schemes are a win for the company planting these trees but not for biodiversity. This is the start of this phenomenon, hence the seriousness of the situation.”

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The paper estimates that a plantation across the combined size of the US, China, Russia and the UK would have to be planted in order to sequester one year of emissions.

While plantations are often more economically viable than standing forests, the paper highlights that they often support a lower level of biodiversity. For example, in the Brazilian Cerrado savanna, a 40% rise in woodland cover reduced the diversity of plants and ants by about 30%.

Campaigners at South Hessary Tor on Dartmoor on Saturday

Simon Lewis, a professor of Global Change Science at University College London, said it was dangerous to treat trees as “nothing more than sticks of carbon”.

“Of course, plantations are needed for the paper and wood products society needs, but rebadging industrial plantations as carbon offsets is yet another problem of the … unregulated carbon offsets market. Tree-planting should not be seen as an alternative to rapidly cutting fossil fuel emissions,” he said.

Thomas Crowther, a professor of ecology at ETH Zurich, who co-authored a paper that found there are 900m hectares (2.2bn acres) of land outside urban and agricultural areas suitable for forests, said placing the carbon value of an ecosystem above everything else was wrong.

“Whenever we value one part of nature more than everything else, we incentivise the propagation of that part at the expense of everything else,” he said. “Historically, we have valued the parts that we use for food, timber, medicines etc, but now we are doing the same thing with carbon.”



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Disease-resistant plants may modulate disease susceptibility in their neighbors

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Disease-resistant plants may modulate disease susceptibility in their neighbors

05/10/2023AgricultureNewsPlant Science

Researchers from INRAE, the Agro Montpellier InstituteCIRAD, the French National Centre for Scientific Research (CNRS) and Yunnan Agricultural University (China) discovered a form of social immunity in wheat and rice. Disease susceptibility in wheat and rice is modulated not only by genetic resistance traits, but also by interactions with neighbouring plants of the same species. The findings, published in PLOS Biology, show that inter-plant cooperation can reduce disease susceptibility by nearly 90 percent in certain cases, as much as is conferred by a plant’s own resistance genes. The findings create new possibilities for improving plant resistance to disease and reducing the use of pesticides.

Reducing pesticide use is a critical issue for agriculture. Mixing crop cultivars is a tool to achieve that aim. There is renewed interest in the practice, and in France today more than 10 percent of the area under wheat cultivation uses mixed crop cultivars. Mixing crop cultivars is known to reduce epidemics by inhibiting the spread of a disease from one plant to another. However, mixtures have variable success in controlling disease. This may in part be caused by yet-unknown interactions between cultivars.

To understand the effects of inter-cultivar interactions, researchers studied the interactions between more than 200 pairs of rice or wheat cultivars in controlled conditions.  They inoculated each pair with a foliar fungal pathogen, and then analysed plant susceptibility to the disease when grown in association with another plant of the same cultivar or with a different cultivar. 

The findings demonstrate that in 10 percent of pairs studied, the presence of a neighbouring plant had an effect on disease susceptibility. With the use of genetic modelling, researchers were able to quantify the effect and demonstrate that certain pairings reduce disease susceptibility in the infected plant by almost 90 percent. This means that disease susceptibility in two major crops, rice and wheat, is modulated not only by the resistance genes of each cultivar, but also by the interactions each plant establishes with its neighbours. In these two crops, we can see a population-level type of cooperation. This may be akin to herd immunity responses found in animal species.

In certain circumstances, inter-plant cooperation can reduce disease susceptibility by as much as is conferred by a plant’s own genes. Consequently, there is considerable potential to strengthen resistance by means other than varietal improvement.


Read the paperPLOS Biology

Article sourceCIRAD

Image: Rice field image. Credit: Pixabay

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EU: Efficacy of mechanical weeding

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EU: Efficacy of mechanical weeding

By MATTHEW TILTOctober 24, 20233 Mins Read

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According to new research conducted by NIAB, a combined approach to weed control can help to reduce reliance on chemical inputs. Non-chemical approaches, including mechanical hoes, have the potential to offset herbicide resistance and reduce reliance on chemical plant protection in conventional cropping.

The results are part of an EU-funded Horizon integrated weed management project, with research undertaken by NIAB research agronomist Will Smith, alongside weed biology and management specialist John Cussans. The project looked at different methods of weed control, specifically control of blackgrass in winter wheat.

Their ultimate aim was to look at ways to reduce herbicide usage in line with impending controls on the use of pre-emergence products and chemical applications, balanced with the EU-wide policy to reduce usage by 50% by 2030. While these do not directly impact the UK, similar targets are anticipated in this country, as continued usage could impact trade with member states.

“Development in the weed control sector is going to be led by non-chemical solutions,” said Mr Smith. “This means consideration of cultural, non-chemical and biological pathways. We also need to look at continued herbicide development, particularly the potential to offset resistance.”

Cultural factors include crop rotation, crop choice and drilling dates, while biological solutions include biocides and biostimulants, as well as non-synthetic herbicides such as organic acids. Particularly interesting to the project was inter-row hoeing, enabling more aggressive cultivation which can remove more established weeds.

Using a Garford Farm Machinery Robocrop hoeing unit, the project found that there was an additional 15% control of blackgrass heads when mechanical weeding was added to a herbicide programme when working in narrow rows. The efficacy was doubled on wider rows.

“Inter-row cultivation adds an appreciable level of control of between 15-25% when combined with herbicides,” explained Mr Smith. “The sweet spot of course is to use IRC in combination with reduced chemical inputs to meet the reduction targets.”

Looking at the margins, the research found that a combination of inter-row hoeing and herbicides is comparable to just using chemical controls, while in low pressure areas, the use of just an inter-row hoe may be preferential. Mr Smith added that the key is changing mindsets, as many conventional growers do not consider mechanical weeding as a viable option.

“What our research indicates is that growers can achieve at least the same or marginally better margins over weed control than currently used methods, with the scope to deliver effective weed control while reducing reliance on chemical solutions,” he said.

Crucially, even if new equipment is purchased to handle mechanical weeding, the additional costings have been calculated at £15 per hectare, based on two passes. Larger scale operations may even see this drop to below £10.

“The research demonstrates the benefits of integrating our range of precision-guided hoes in broadacre arable crops, for both conventional and organic systems,” said Allan Knight, Garford Farm Machinery technical sales and marketing manager.

As agrochemicals are withdrawn from the market, more and more conventional farmers are beginning to appreciate hoes as a more appropriate solution, in combination with other weed controls.

“While previously non-chemical approaches have been seen as an expensive add-on to conventional herbicide programmes, the addition of mechanical weed control products as part of an integrated weed management system offers a cost-effective and sustainable solution to growers,” he concluded.

For more information go to www.garford.com



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Australia: New organoids boost pest rabbit control

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Australia: New organoids boost pest rabbit control

by Ian Dewar, CSIRO

Rabbit-like rabbit liver organoid. Credit: Dr Egi Kardia CSIRO

Australia has been locked in a battle to control rabbits since the 1950s. Rabbits cause huge damage to our environment. They compete with native species, overgraze native plants and cause erosion. High rabbit numbers can also help sustain large populations of other invasive species, notably feral cats and foxes.

A recent global assessment report by the United Nations found invasive alien species such as rabbits are the leading cause of biodiversity loss and species extinction in Australia. Keeping their numbers low over long periods of time is essential for Australia’s biodiversity and rural industries.

The best way to control rabbits across the landscape is to use self-sustaining biological control (biocontrol) methods. Biocontrol uses biological agents such as natural enemies or diseases to manage pest species.

Australia’s rabbit control programs

European rabbits infest two-thirds of Australia and are a serious threat to our native species.

Rabbits are expensive to control using poisons, burrow fumigation, shooting and trapping. What’s more, these methods are ineffective in the long term and at large scales. Rabbits are estimated to cost on average $216 million a year in lost agricultural productivity. They are our most costly invasive alien species for agriculture.

New organoids boost pest rabbit control
Close up of rabbit liver organoid cells. Virus proteins in green. Cell nuclei in blue. Liver cells in red. Credit: Dr Egi Kardia CSIRO

Australia’s rabbit biocontrol programs employed the Myxoma virus in 1950 and the rabbit hemorrhagic disease virus (RHDV, also known as rabbit calicivirus) in 1995. They have been extremely successful in drastically reducing pest rabbit numbers in Australia at scale. These two viruses are host specific. This means they attack only rabbits and, in some cases, closely related species such as hares.

These viruses have saved Australian agriculture over $70 billion. It makes them our greatest invasive alien species management success story.

However, there is no status quo in rabbit biocontrol: the viruses and rabbits constantly co-evolve. Surviving rabbits develop resistance and varying levels of immunity, leading to numbers bouncing back.

Current research aims to help the RHDV stay ahead in the co-evolutionary arms race with its rabbit host. This will protect the gains made by the past successful biocontrol initiatives and keep rabbit numbers below the damage threshold.

In a major breakthrough, our scientists have now developed new ways to grow and study rabbit biocontrol viruses outside of live animals. They’ve developed organoid culture systems based on liver cells from already culled wild rabbits and hares around Canberra. Organoids are tiny 3D cellular structures that mimic the cells of the organ they come from. They act very similarly to the organ so represent a life-like model. The findings are published in the Journal of General Virology.

New organoids boost pest rabbit control
Close up of rabbit liver organoid cells. Virus genetic material in green. Cell nuclei in blue. Credit: Dr Egi Kardia CSIRO

Scientists have been trying to achieve this for 40 years, and this is the first time they’ve been able to grow these viruses in a cell culture outside of an animal. Our researchers found that two types of Rabbit Hemorrhagic Disease Virus (RHDV) replicated successfully in the organoids. The first is known to only infect rabbits. The second can infect rabbits as well as hares.

Both viruses replicated successfully in rabbit organoids, but only the virus known to also infect hares replicated in the hare organoids. The team also made organoids derived from cat and mouse livers. However, RHDV did not replicate in these. This finding shows these viruses are very host specific only to lagomorphs (rabbits and hares). We also know that these viruses are not zoonotic so pose no risk to humans. Their research paper is available to view publicly.

Until now, studying these viruses has been difficult due to the lack of a reliable cell culture system. This new model will make research into viruses like these easier and faster. It will also reduce the need for testing on live animals.

The establishment of this culture system for rabbit viruses is significant. It will allow scientists to study the viruses in a controlled environment. This could help further our understanding of the diseases they cause and develop further biocontrol strategies.

More information: Egi Kardia et al, Hepatobiliary organoids derived from leporids support the replication of hepatotropic lagoviruses, Journal of General Virology (2023). DOI: 10.1099/jgv.0.001874

Provided by CSIRO 


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How Systematic Entomology Will Thrive in the Age of Artificial Intelligence

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ENTOMOLOGY TODAY  4 COMMENTS

Artificial intelligence (AI) may be the next disruption in biodiversity documentation, as it will be in countless fields. As a simple illustration of the power of generative AI, this image was created with the image generator DALL-E with the parameters “a scientist in a futuristic laboratory employs AI-powered technology to study and preserve a vibrant ecosystem of insects.” (Image created via DALL-E by G. Christopher Marais)

By Jiri Hulcr, Ph.D., Andrew J. Johnson, Ph.D., and G. Christopher Marais

G. Christopher Marais

Andrew J. Johnson, Ph.D.

Jiri Hulcr, Ph.D.

In a recent New York Times profile, Mauricio Diazgranados, the new director of the New York Botanical Gardens, shared a message that many scientists grapple with: “We just cannot keep doing the science as we are used to doing. Can we keep going into the field, bringing in and describing new species while the whole world is tearing apart and burning?”

Does Mauricio’s message resonate with entomologists? Our own field, systematic entomology, often struggles with this question: Should we focus on providing solutions to contemporary issues, or should we keep documenting the world’s biodiversity? By spending our careers documenting insect species and their relationships instead of solving the world’s immediate problems, are we potentially threatening the survival of our field?

We believe that history shows the answer: Documenting biodiversity is here to stay as one of the foundations of biological sciences. What we need is to keep evolving how we do it. Our survival will be a result of our ability to retool.

Systematists Have Repeatedly Evolved

A few decades ago, traditional systematic entomology was derided as stamp collecting, an outdated field soon to be replaced by (back then) cladistics, phylogenetics, and studies of evolutionary processes. Turns out, systematics as a whole survived and is thriving, while cladistics not so much.

A decade or two later, molecular biology swept in by storm. Taxonomy was once again predicted to go extinct, and taxonomists were deemed a dying breed. Yet, as we filled GenBank with millions of DNA sequences, we found ourselves unable to place them in a meaningful context, or even label them with names. Instead of going extinct, experts familiar with organisms became a hot commodity, and new programs at the National Science Foundation increased funding for documenting biodiversity.

Systematics has survived and thrived because each new generation of systematists has embraced the new tools that time has brought.

How Systematics Can Become “Machine Intelligible”

What’s hot now? Artificial intelligence (AI). Language models and image recognition may be the next disruption in biodiversity documentation. When iNaturalist is in everyone’s pocket, it is time to assess what systematic entomology needs to do to keep itself relevant, well-funded, and thriving.

Our lab has toyed around with machine learning, which has resulted in two outcomes: a prototype AI bark beetle classifier, and a profound realization of the importance of people with in-depth familiarity with the organism. Once again, as we are adapting our field to the use of new tools, we need the humans who crawl through bushes, sift leaf litter, and spend time peering at museum drawers to be the arbiters of what is biological truth versus what is an artifact of an algorithm. And, once again, taxonomists may become increasingly important—but only to the extent that we can cooperate with the machine.

Here is what it means for systematists to be “machine intelligible.”

1. Our outputs need to embrace the machines’ hunger for data. Even the good old “stamp collecting” entomology, as in specimen accumulation, has become valuable again. The key will be turning the specimens into data and making those available. So, to our fellow systematists: Please publish your images, and label them lavishly. Publish your morphological descriptions with ample details. Publish field observations and host associations. The machines keep harvesting our data off the web; make sure yours are there. If your collection is not online, it is not helping the common cause. If we feed the models enough morphological terms, one day you will be able to identify your bug by talking about it to your computer.

2. We humans should be more disciplined about our vocabularies. This does not mean that we need to write like robots. While the recent era of relational databases required strict consistency in format and spelling, the new era of natural language models, fuzzy matching, and graph databases does not strictly require that. What’s more important is the volume and repetition of statements that are accurate. Statements do not necessarily need to be unified, or even grammatically correct; rather, they have to be factually accurate. From now on, we need to be much more careful to distinguish what we know for sure, and what is a hypothesis. If we are not sure, it is our responsibility to state the doubt.

The taxon we study, bark and ambrosia beetles, is a good example. Thousands of publications report trees being killed by these beetles. So, if you ask ChatGPT whether, for example, beetles in the Ips genus kill trees, it will report with high confidence that they do. But that is not true for the great majority of Ips species, including nearly all in the United States. This response is a result of an over-emphasis in published work on one European tree-killing pest, while at the same time we collectors and systematics consistently fail to report when all the other Ips beetles are just secondary colonizers of dead trees.

One more word on language: Perhaps you are already using Darwin Core format for your data; great. But now let’s think about it a bit differently. Don’t think about language rules as restraints. Instead, think about the need to tell everything that you know, even if it is repeated and boring. Learn about ontologies and try to adopt one in your work.

3. We must keep collecting! Even as AI models grow increasingly intelligent, in the end it will be you, your specimens, and your knowledge of them required to steer the machines in the murky waters of truth and knowledge. Artificial intelligence routinely distorts human beliefs about the world just by sampling biases and doesn’t know it. With the global homogenization of biota on one hand and rampant extinctions on the other, generating real data, not simulations, has become more important than ever. Here in Florida, the state Department of Agriculture’s Division of Plant Industries—an agency very much immersed in applied science—developing a regional taxonomy hub staffed with human taxonomists, not machines. Why? Because their biggest problem is recognizing and documenting new invasive pests that nobody has ever seen before.

The Future of Describing the Natural World

Ahead lie some exciting times for systematics. What comes after the AI machines have been trained for systematic work? What comes after the point where machines are more accurate than people at predicting the identity of organisms? What happens when the processes to train them have also been automated? How will taxonomy survive? Right now we are still doing most of the describing, sequencing, and photographing of the biological world, but soon robots may be better at these and take up much of the grunt work. What role will trained taxonomists fill then? Where will the frontier of the field lie, the tasks at which we can still “outcreate” the machines? We do not know yet.

We do know that taxonomists are primed to fill a translational role between machines and people, both other scientists and the public. We may need more training in interpreting the complexities of the world in digestible ways. In other words, we may be needed to bridge the gap between machines, people, and nature itself.

Jiri Hulcr, Ph.D., is an associate professor with the School of Forest, Fisheries, and Geomatic Sciences and the Department of Entomology and Nematology at the University of Florida and principal investigator at the UF Forest Entomology Lab. Email: hulcr@ufl.eduAndrew J. Johnson, Ph.D. (ajj@ufl.edu) is an assistant research scientist and G. Christopher Marais (gmarais@ufl.edu) is a master’s student and graduate assistant in the lab.

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The hidden threat of the Coconut Rhinoceros Beetle

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The hidden threat of the Coconut Rhinoceros Beetle

Pacific Invasion: The hidden threat of the Coconut Rhinoceros Beetle

The Pacific Community (SPC) is stepping up its efforts to combat the Coconut Rhinoceros Beetle (CRB), a destructive pest that poses a significant threat to the Pacific’s tree of life, the coconut. This invasive species has been causing havoc in the region and is jeopardizing the coconut industry. 


Pacific Island Countries and Territories (PICTs)  supply 50 per cent of the world’s copra trade, with Papua New Guinea being the world’s largest copra supplier, followed by Vanuatu. Copra, the dried flesh of the coconut, is used in many consumer products, as well as for animal feed. Other Pacific countries, such as the French Polynesia,  are also trying to develop the copra  sector,  making products with high added value from the nut itself and other parts of the coconut tree, including  virgin oil, coconut water and coconut sugar.

The coconut industry has faced significant challenges due to climate change in recent years. Rising temperatures, increased CO2 concentration, changing precipitation patterns, and the proliferation of weeds resulting from climate change have all contributed to the vulnerability of coconut plantations.

Additional challenging issues included degradation of soil fertility in coconut plantations, and increased incidence of pests and diseases that have become more prevalent.

The Pacific is now straining to sustain coconut production while simultaneously improving resilience and reducing vulnerability to climate change impacts. An August  2017 alert identified a new danger to the Pacific that devastates coconut palms and has expanded rapidly across the region. This new threat is the invasive coconut rhinoceros beetle.

The beetle first arrived in the Pacific in 1909 through a potted rubber seedling brought in from Sri Lanka to Samoa. Originally native to South Asia, the beetle was able to expand its range and establish itself in the Pacific through increased sea and air transport movement.  

In 2020, the Pacific Community received funding from the New Zealand Ministry of Foreign Affairs and Trade (MFAT) through the Pacific Awareness and Response to Coconut Rhinoceros Beetle (PARC) project to address this urgent invasive pest issue. SPC has led a holistic approach to stopping the Beetle that involves awareness, surveillance, border monitoring and integrated management. A free online data collection toolkit called Kobo Toolbox has been rolled out for centralisation of Beetle outbreak data. SPC is working with its country and industry partners to stop the Beetle so they can intensify coconut production, ensuring that the industry can thrive while minimising the pest’s impact.     

SPC has additionally signed agreements with Papua New Guinea’s National Agriculture Quarantine (NAQIA), PNG Kokonas Indastri Koporesen (KIK) and Biosecurity Vanuatu to assist them in their efforts to control the coconut rhinoceros beetle, particularly the CRB-G variant that is resistant to virus used as an effective biological control agent.

“It is imperative that there is effective awareness and training to inform the public of the CRB situation in the country. We also need to disseminate this information to target groups and carry out sanitation and clean-up programmes to control CRB breeding sites,” Says NAQIA Technical and Advisory General Manager, Mr. David Tenakanai.

The coconut rhinoceros beetle, is a pest species occurring in tropical regions.

Adults can cause extensive damage to economically important wild and plantation palms.

Adults can live as long as 5 months and gravid females lay 50-100 eggs throughout their lifetime.

To help raise awareness, SPC has created a manual for control and management of the pest in Pacific Island countries and territories. Approximately 600 training manuals on CRB control and management have been published and distributed in Vanuatu, Solomon Islands and Papua New Guinea.

Overall, these proactive approaches will not only safeguard the livelihoods of those involved in the coconut industry but also contribute to the overall food security and economic stability of the PICTs.

A Vanuatu biosecurity team and SPC Coconut Rhinoceros Beetle lead Mark Ero (bottom right) on a mission.

Contacts

Matilda Simmons, Communications Officer, Pacific Community’s Land Resources Division | matildas@spc.int

Maëva Tesan, Information, communications and knowledge management Communications Officer – Climate Change and Environmental Sustainability Programme | maevat@spc.int

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Insects Turn Plants Into Pollution Detectors

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A wide variety of insects cause their host plants to form protective galls, such as this stem gall on goldenrod, shown here. These abnormal growths are rich in nutrients—as well as contaminants the plant might absorb from the soil. New research shows these insect-induced galls can double as highly sensitive pollution detectors. (Photo by Leslie Mertz, Ph.D.)

By Leslie Mertz, Ph.D.

Leslie Mertz, Ph.D.

Insect-induced galls that appear as lumps on plant stems and bumps on leaves may also be excellent pollution detectors, according to research presented at the 8th International Plant Gall Symposium 2023 held at California State University, Chico, in July.

Evolutionary ecologist Glen Ray Hood, Ph.D., of Wayne State University in Detroit, explained his lab’s work demonstrating that galls accumulated toxic soil contaminants at the sites of two highly publicized, factory-discharge incidents in southeastern Michigan: one in Ann Arbor that released 1,4-dioxane and the other in Madison Heights that released hexavalent chromium and eventually seeped as a bright green ooze onto a busy nearby freeway.

At the Plant Gall Symposium, Hood also described his lab’s current Detroit-centered project that uses plant galls to detect below-ground, anthropogenic (i.e., human-made) volatile organic compounds (VOCs), some of which have been associated with the city’s high preterm-birth rate, among other health issues.

An Idea That Grew

Glen Ray Hood, Ph.D.

Hood originally got the idea to study how insect-induced plant galls interact with ground pollution while he was a postdoctoral researcher at Rice University. There, he came across a nearly 30-year-old journal article about blueberry stem galls. These often peanut-shaped galls are abnormal plant growths caused by a tiny wasp, Hemadas nubilipennis, laying its eggs in the tips of the plant’s stems. “The study authors simply asked whether heavy metal contaminants from an ore smelter accumulated in higher concentrations in some plant tissues versus others,” he says. “And they showed the plant was definitely sending higher concentrations to galls.”

The finding made sense because of the way galls are formed, according to Hood. In most cases, the insect’s egg-laying hijacks the plant’s developmental system, causing it to make a gall, and the saliva of the resulting, feeding larva incites the plant to transport soil resources to the gall, which continues to grow. “In fact,” he says, “oftentimes the gall, which is made of plant tissue and surrounds the growing larva, is thousands of times more nutrient-rich than tissue found anywhere else in the plant during its entire life cycle—so, more than nutrient-rich seeds, fruit, or even flowers.”

Hood wondered whether the plant was accumulating other subsurface contaminants in galls, and when he started his own lab at Wayne State about five years ago, he began exploring galls as so-called “phytoscreening” tools for the two southeast Michigan chemical spills.

Closeup of a goldenrod stem on which a gall has formed. The stem and gall are medium reddish-brown in color. The gall is about twice as thick as the stem extending below and above the gall. Above and below, narrow green leaves grow out from the stem. At the top of the picture, yellow goldenrod flowers can be seen, out of focus, in the foreground.
Closeup of a green leaf with a jagged edge. In three spots on the leaf, small round growths have formed, each the same medium-green color as the leaf and slightly fuzzy in texture.

For hexavalent chromium in Madison Heights, Hood and his group took harvested galls from various plants along half-kilometer transects running in four directions from the point source, sealed the galls in methanol-filled jars and sent them to a lab for analysis. Their goal was to determine whether gall tissue had higher concentrations of the contaminant than did other plant tissues. “About 85 percent of the time, the answer was yes,” Hood says. “And it didn’t matter which plant species or which plant tissue—stem, fruit, flower, or leaves—the gall was on or which insect was responsible for the gall. The gall always showed higher concentrations than other plant tissues.”

For 1,4-dioxane in Ann Arbor, Hood and his group, including former undergraduate Connor Socrates and current doctoral student Sarah Black, tested one gall that is nearly ubiquitous on wild grape, a very common plant, and is initiated by an aphid-like insect known as grape phylloxera (Daktulosphaira [Viteus] vitifoliae). Results of sampling and analysis showed that the galls were far more sensitive to the presence of dioxane than other plant tissues were. Since then, they have continued to sample galls in Ann Arbor, and soon-to-be-published findings of that work show gall-identified dioxane beyond the currently known extent of the dioxane plume, which is continuing to migrate in groundwater, Hood says.

“In addition, at some areas inside the plume where well water is coming back negative in traditional tests, we are finding dioxane in galls growing in plants right next to the well,” he says. “This suggests that galls might be a viable and maybe superior alternative for doing dioxane testing.”

Early Progress

Hood’s current Detroit VOC project is part of Wayne State’s new multidisciplinary Center for Leadership in Environmental Awareness and Research (CLEAR), funded by the National Institute of Environmental Health Sciences. For this work, he and his group are sampling galls for a wide variety of VOCs, including such notable toxins as benzene, toluene, ethylbenzene, and xylene, as well as tri- and tetrachloroethylene. They’re also collaborating with other research groups that are investigating VOC levels in the atmosphere as well as in the blood and urine of local residents.

“One of the interesting things we have already found is that VOCs are spread out all over Detroit, including both in blighted areas and affluent areas,” Hood says. “And as it turns out, some of the highest concentrations are appearing in plants growing right against homes in affluent areas.”

With that work well under way, the researchers are delving into the details. “Once we can screen numerous common and commonly galled plants, that will tell us things like which galls are the best contamination detectors, at which time of year and under which environmental conditions they work best, and which chemicals can and cannot be detected with galls,” Hood says. “Once we have those questions answered and the screening method perfected, we want to use galls to identify VOC hot spots in the city, which can help bring about cleanup efforts.”

He adds, “It’s still early on in this research, but from our studies so far, it looks like these pretty common things—galls—may be one of the best ways to quickly detect chemical contaminants in many, if not most, environments on the planet.”

Learn More

On the phytoscreening potential of insect-induced plant galls

Plant and Soil

Ento-phyto-screening for organic contaminants: The use of insect-induced plant galls as a novel tool for tracking belowground chemical contaminants,” Student 10-Minute Paper; Medical, Urban, and Veterinary Entomology Section

Entomology 2023, November 5-8, National Harbor, Maryland

Leslie Mertz, Ph.D., writes about science and runs an educational insect-identification website, www.knowyourinsects.org. She resides in northern Michigan.

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Regenerative farming is unleashing the power of the ladybird

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October 23, 2023

In 1478 the farmers of Berne, Switzerland, had had enough. A plague of beetles was wreaking havoc in their crops. Finally, after all attempts to remove the beetles had failed, a complaint was raised to the bishop of Lausanne. The bishop put the beetles on trial and, after finding them guilty, sentenced them to excommunication.

The trial was not unusual. During the Middle Ages insects and other pests were routinely tried by ecclesiastical courts. A plague of crop-destroying beetles could be a matter of life and death, so it may be no wonder that desperate citizens sought help from higher powers.

Perhaps the farmers of Berne could have looked closer to home for help, however. Today, regenerative farming techniques have shown that one of the best defences against insects is other insects. A single ladybird, for instance, can consume 5,000 aphids in its lifetime. They aren’t fussy eaters and will consume many of the most damaging pests in agriculture.

Ladybirds are, in effect, a natural pesticide. Yet, like most insect species, native ladybird populations are under threat,1 often they are unintended casualties in our escalating war on pests.

Ladybirds are, in effect, a natural pesticide. Yet, like most insect species, native ladybird populations are under threat

 The age of agro-chemicals

History is full of inventive approaches to pest control. As long ago as 2,500 BCE, the Sumerians were using sulphur to kill off insects. In 19th century UK, the Victorians had a no-nonsense approach to protecting their apple trees against aphids and birds – they smeared the trees with arsenic. “Wash the apples well afterwards,” was the advice.

More recently we have sought less toxic alternatives. Since the 1950s, modern monoculture farming techniques have relied on carefully formulated agro-chemicals – fertilisers, insecticides, bactericides, fungicides and herbicides. In a roundabout way these chemicals even dictate what we eat – for example, most soya beans and corn now come from plants genetically engineered to resist weed killer2.

These innovations have led to extraordinary increases in crop production. Often dubbed the ‘Green Revolution’, between 1960 and the start of the new millennium cereal yields more than doubled despite the amount of land given over to growing them staying relatively stable.3 According to the UN’s Food and Agriculture Organisation, each year we now spray more than a third of a kilogram of pesticides for every person on Earth.4

Is pest control out of control?

Pests, it turns out, don’t take this chemical onslaught lying down. Over time, they evolve to tolerate particular products. In turn, farmers resort to ever more toxic formulations that can have wider negative environmental impacts. Neocotinoids, for instance (a branch of insecticide largely banned in the UK and EU but still widely used elsewhere), are up to 10,000 times more deadly to bees than earlier insecticides.5 In effect, we are engaged in a game of whack-a-mole on a planetary scale, only the moles and the hammers are getting bigger.

For the environment, this escalating battle can have dire consequences. In Germany, researchers found that the total number of flying insects such as ladybirds and wasps fell by around 80% between 1990 and 2017– unintended exposure to pesticides is thought to be largely to blame7. (For birds, this fall in insect numbers has been calamitous – across Europe, the bird population has fallen by more than 500 million over the last 40 years.8)

Pesticides’ indiscriminate impact is felt below ground, too, where years of accumulated spraying make life miserable for earthworms and other invertebrates

Pesticides also linger in the environment. In the Canadian province of New Brunswick, DDT, the now-banned grandfather of modern insecticides, was found in high concentrations in some lakes fifty years after it had last been sprayed onto neighbouring forests. Despite the passage of half a century, researchers believed that the DDT was still causing algal blooms and reducing fish stocks.9

Pesticides’ indiscriminate impact is felt below ground, too, where years of accumulated spraying make life miserable for earthworms and other invertebrates. Earthworms are essential for soil health, but fungicides and insecticides can stunt their growth and hamper their ability to reproduce.10

Read also: Soil: food’s forgotten superhero

Restoring the natural balance

In the early 2000s, Alvarro Nietro, a vegetable farmer in Central Mexico, stumbled upon a natural solution. Nietro had been forced by food production regulations to set traps for mice in his field. Nietro discovered that the mice being killed weren’t interested in his crops: they just wanted the water which he had diverted to irrigate the crops. He decided instead to make small ponds outside the fields: “If they want water, why not give them water?” he reasoned. The mice stopped coming into the fields and the traps lay empty.

It was a simple solution, but, according to Nietro, “it changed everything.” Soon, owls and eagles came to feed on the mice. Inspired by the resurgence in life, Nietro planted 10,000 native trees in areas which weren’t being actively farmed. These ‘wild, bio-corridors’ became host to bats, squirrels, deer and even a cougar.

The need for pesticides was almost entirely eliminated since the wildlife in the bio-corridors controlled pests naturally, saving money and labour. “Once you help nature restore the balance, you restore everything, even your economy,” Nietro says. “I tell all the growers: do it for the love, or do it for money, but do it.”11

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