Temporal dynamics of predatory nematodes in Guam reveal effective biological control of Meloidogyne spp.

University of Guam

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

Richard Singh, an assistant professor with the UOG Land Grant agInnovation Research Center, examines plant roots under a microscope to look for evidence of any nematodes.

view more 

Credit: Photo of the University of Guam

A newly published study from the University of Guam sheds light on a tiny but powerful ally in the soil and how it could help Guam farmers and growers protect their crops naturally.

Published on Dec. 11, 2025, in the journal Frontiers in Plant Science, the study was conducted by Dr. Richard R. Singh, an assistant professor of sustainable plant production, and soil chemist Clancy Iyekar of the agInnovation Research Center under UOG Land Grant. The study focuses on nematodes — microscopic roundworms in soil that are poorly documented in Guam — specifically exploring how certain “good” nematodes may help control the harmful ones that damage crops.

Tiny worms, big impact

Bananas are one of the most important local crops in Guam, contributing significantly to food security, cultural traditions, and small-scale farm income across the island. But they are vulnerable to plant-parasitic nematodes, especially root-knot nematodes.

Plant-parasitic nematodes in banana plants cause root galls that reduce the plant’s ability to absorb water and nutrients. This leads to poor plant growth, yellowing, plant toppling, and reduced yields. They also cause indirect losses by predisposing plants to secondary infections and transmitting pathogens.

Plant-parasitic nematodes are estimated to cause hundreds of billions of dollars in crop losses globally each year. Without timely research and attention, their impact could escalate into a much larger agricultural threat in the future, Singh said.

Nematodes found in Guam

The research team studied five banana cultivars grown at UOG’s Inalåhan Research & Education Center in southern Guam. They found that all cultivars had similar levels of plant-parasitic nematodes in their roots. The most dominant harmful species was root-knot nematode (Meloidogyne species) — about four to five times more abundant than other damaging types.

However, the researchers also discovered something encouraging: The soils contained high numbers of beneficial nematodes, including predatory nematodes (Mononchus species) that feed on plant-parasitic nematodes.

“Not all nematodes are harmful,” Singh said. “Our soils in Guam are full of beneficial nematodes that actually help regulate pest populations. It’s a natural system of checks and balances happening underground.”

The study showed that plant-parasitic nematodes made up only about 13% of the total nematode community in the banana root zone. In contrast, bacterivores (which help recycle nutrients) made up about 40%, and predatory nematodes accounted for up to 30%. Importantly, the number of harmful nematodes detected in banana roots — an average of 34 per 100 grams — is well below commonly cited damage thresholds, which are often around 100 per 100 grams of root tissue.

“This indicates that in our study site, natural suppression may already be occurring,” Singh said. “That’s good news for local growers.”

Soil tests at the study site also revealed high levels of organic matter, carbon, and nitrogen — conditions that support beneficial soil life.

Predator-prey dynamics: ‘Effective when given time to work’

To better understand how predatory nematodes control harmful ones, the team conducted controlled greenhouse experiments using tomatoes as a model crop.

When root-knot nematodes were introduced alone, plants developed heavy galling. But when predatory nematodes were added, significant reductions were observed over time, including:

• 3- to 5-fold reductions in gall formation
• 4.5- to 7.5-fold reductions in egg-laying females
• major declines in juvenile nematode populations.

The effects became stronger six and eight weeks after inoculation, demonstrating that biological control improves over time.

“This is one of the first studies in nematology to explore temporal dynamics — how predator-prey populations change over time,” Singh said. “It shows that biological control isn’t instant, but it can be very effective when given time to work.”

What this means for Guam farmers and residents

For Guam’s agricultural community, the study reinforces the importance of maintaining healthy soil. Soils rich in organic matter — such as compost, wood chips, grass clippings, and animal manure — support beneficial nematodes that suppress harmful species.

This research also provides a scientific foundation for the potential use of predatory nematodes as a biopesticide in the future — a process that would require regulatory clearances and ensuring ecological safeguards through contained field trials and environmental safety testing.

“By working with nature instead of against it, we can protect our crops, improve soil health, and strengthen food security for the island,” he said.

The study was funded by the USDA National Institute of Food & Agriculture through the Hatch Program.

 

Rows of banana plants growing on the University of Guam’s Inalåhan Research & Education Center in southern Guam. A UOG study published in December 2025 found that all cultivars on the research station had similar levels of plant-parasitic nematodes in their roots, but the soils also contained high numbers of beneficial nematodes.

(Left) A female nematode extracted from galls of a dissected banana plant root. (Right) The same nematode stained pink.

Credit

Photo of the University of Guam

---

Journal

Frontiers in Plant Science

DOI

10.3389/fpls.2025.1715934 

Article Title

The role of predatory nematodes in managing plant-parasitic nematodes: community dynamics and microbial implications in tropical soils

 

Pioneering AI tool predicts building emissions from simple text descriptions

University of Bath

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

Researchers at the University of Bath have developed the first artificial intelligence (AI) tool that predicts the carbon footprint of buildings from simple text descriptions, giving architects real-time feedback on sustainability at the earliest design stage. From a conversational description of a proposed building, the tool uses machine learning and natural language processing to predict the embodied carbon, the carbon emissions associated with materials and construction throughout the building’s life cycle. It provides architects with instant feedback on the sustainability of their plans right at the start of the design process, where the potential for carbon saving is greatest. Buildings and infrastructure account for more than a third of the carbon emissions from industrialised nations. Several models already exist to reduce the day-to-day emissions of heating and powering buildings, but using software to design out embodied carbon is much less common. Professor David Coley, Professor of Low Carbon Design in the Department of Architecture and Civil Engineering and an author on the paper, said: “Architects designing sustainable buildings often lack the level of detail they need to analyse the materials and construction processes involved in the final build. Traditional tools often address embodied carbon via material mass accounting methods. "However, these tools rely on precise material breakdowns, accurate quantities and specialist engineering knowledge. Our tool would allow designers to quickly assess and refine their designs to maximise sustainability long before formal specifications are locked in.” The tool transforms simple descriptions of the building, such as the materials, dimensions and usage, into credible carbon emission estimates. As the designs evolve and descriptions become richer and more detailed, the method naturally refines its carbon estimate. It is designed not to provide final answers, but to generate predictions accurate enough to guide conversations. In addition to providing informed decision-making for lower-carbon buildings, the tool can also suggest improvements to their environmental conditions, such as increased natural light, enhanced thermal comfort, or better acoustics. It could also play a part in architectural education, promoting sustainability awareness at earlier stages of design thinking, without requiring advanced or specialist knowledge. The team tested their tool in real-world design settings, with 43 building professionals using it on their projects. In one example, designers used the tool to assess the embodied carbon of a high-end glass and masonry building near Exeter, UK, throughout the design cycle. This allowed them to adjust the insulation, wall construction, and glazing to reduce the embodied carbon, without knowing the material quantities. The feedback from industry has been overwhelmingly positive, especially around how easy the tool is to use and how well it fits into existing workflows. To overcome the lack of publicly available real-world embodied carbon data, the team trained the AI using a synthetically generated dataset based on 150,000 buildings. This enabled development and feasibility testing of the model; however, it can be retrained on higher-quality, real-world datasets as soon as they become available to improve accuracy. The tool’s natural language processing handles the wide variation and ambiguity in typical building descriptions, correctly identifying key materials like steel, concrete and timber 80% of the time. It proved linguistically robust, analysing several differing descriptions of the same building with minimal changes to the predicted carbon emissions, and correctly ranked real buildings by their embodied carbon intensities. This innovative tool could help the construction industry meet net-zero targets and embed sustainable design at the very earliest stages. The team plans to refine the tool as more real-world data becomes available and explore further applications in industry and educational settings.   ENDS   Notes to editors:  For more information, please contact Sarah Baker-Gaunt at the University of Bath Press Office on press@bath.ac.uk

About the University of Bath The University of Bath is one of the UK's leading universities, recognised for high-impact research, excellence in education, an outstanding student experience and strong graduate prospects. We are ranked among the top 10% of universities globally, placing 132nd in the QS World University Rankings 2026. We are ranked in the top 10 in all of the UK’s major university guides. The University achieved a triple Gold award in the last Teaching Excellence Framework 2023, the highest awards possible, for both the overall assessment and for student outcomes and student experience. The Teaching Excellence Framework (TEF) is a national scheme run by the Office for Students (OfS). We are The Times and The Sunday Times Sport University of the Year 2026. Research at Bath is shaping a better future through innovation in sustainability, health, and digital technologies. Find out all about our Research with Impact: http://bit.ly/3ISz1Wu

---

Journal

Architectural Engineering and Design Management

DOI

10.1080/17452007.2026.2613773 

ANCIENT NEW AGE

Chimps’ love for crystals could help us understand our own ancestors’ fascination with these stones

Ancestors of modern humans collected crystals for which they had no apparent use. A new chimp study could help researchers understand the roots of this infatuation

Frontiers

FacebookXLinkedInWeChatBlueskyMessageWhatsAppEmail

 

image: 

Chimp Toti attentively observes the quartz crystal during Experiment 1. 

view more 

Credit: García-Ruiz et al., 2026

Crystals have repeatedly been found at archaeological sites alongside Homo remains. Evidence shows hominins have been collecting these stones for as long as 780,000 years. Yet, we know that our ancestors did not use them as weapons, tools, or even jewelry. So why did they collect them at all?

Now, in a new Frontiers in Psychology study, scientists in Spain investigated which characteristics of crystals may have made them so fascinating to our ancestors. They designed experiments with chimpanzees – one of the two great ape species most closely related to modern humans – to identify the physical properties of crystals that may have attracted early hominins.

“We show that enculturated chimpanzees can distinguish crystals from other stones,” said lead author Prof Juan Manuel García-Ruiz, an Ikerbasque Research Professor on crystallography at the Donostia International Physics Center in San Sebastián. “We were pleasantly surprised by how strong and seemingly natural the chimpanzees’ attraction to crystals was. This suggests that sensitivity to such objects may have deep evolutionary roots.”

The Monolith

Modern humans diverged from chimps between six and seven million years ago, so we share substantial genetic and behavioral similarities. To find out if fascination with crystals is one of them, the researchers provided two groups of enculturated chimpanzees (Manuela, Guillermo, Yvan, Yaki, and Toti in group one and Gombe, Lulú, Pascual, and Sandy in group two) from the Rainfer Foundation with access to crystals.

In the first experiment, a large crystal – the monolith – was placed on a platform, along with a normal rock of similar size. While initially both objects caught the chimps’ attention, soon the crystal was preferred and the rock disregarded. Once they had removed it from the platform, all chimps inspected the crystal, rotating and tilting it so they could view it from specific angles. Yvan then picked up the crystal and decisively carried it to the dormitories.

Interest was strongest early after exposure and declined very gradually over time, the team observed. The same pattern is found in humans as the novelty of an objects fades. When caretakers tried to retrieve the crystal from the chimps’ enclosure, they had to exchange it for favored snacks: bananas and yogurt.

A crystal-clear preference

A second experiment showed that the chimps could identify and select smaller quartz crystals – similar in size to those collected by hominids – from a pile of 20 rounded pebbles within seconds. When pyrite and calcite crystals, which have different shapes than quartz crystals, were added to the pile, chimps still were able to pick out crystal-type stones. “The chimpanzees began to study the crystals’ transparency with extreme curiosity, holding them up to eye level and looking through them,” García-Ruiz said. Chimps repeatedly examined the crystals for hours.

Sandy, for example, carried pebbles and crystals in her mouth to a wooden platform where she separated them. “She separated the three crystal types, which themselves differed in transparency, symmetry, and luster, from all the pebbles. This ability to recognize crystals despite their differences amazed us,” García-Ruiz said. Chimps also do not usually use their mouths to carry objects, so this behavior could mean they were hiding them a behavior consistent with treating the crystals as valuable, the team pointed out.

Crystals in our minds

The study did not examine if some chimps were more interested or laid more claim to crystals than others, although future studies should take chimp personalities into account, the team said. “There are Don Quixotes and Sanchos: idealists and pragmatists. Some may find the transparency of crystals fascinating, while others are interested in their smell and whether they’re edible,” García-Ruiz pointed out. The chimps tested here also are used to contact with humans and familiar with objects not found in the natural world. Therefore, the same experiments should be carried out with less enculturated species, ideally wild apes.

The combined observations from the experiments identified both transparency and shape as alluring properties. It might have been the same qualities attracting early humans to these rocks. The clouds, trees, mountains, animals, and rivers of the natural world surrounding our ancestors were defined by curvature and ramification, so few items had straight lines and flat surfaces. Crystals are the only natural polyhedral, meaning the only natural solids with many flat surfaces. When early humans tried to make sense of their environment, their cognitive processes might have been drawn to patterns that were unlike what they knew. 

“Our work helps explain our fascination with crystals and contributes to the understanding of the evolutionary roots of aesthetics and worldview,” concluded García-Ruiz. “We now know that we’ve had crystals in our minds for at least six million years.”

---

Journal

Frontiers in Psychology

DOI

10.3389/fpsyg.2026.1633599 

Method of Research

Experimental study

Subject of Research

Animals

Article Title

On the origin of our fascination with crystals

Article Publication Date

4-Mar-2026

Yvan's interaction with small crystals. He brought the crystal very close to his eye and inspected it carefully, repeating the action several times. This episodic inspection lasted for more than 15 minutes.

Credit

García-Ruiz et al., 2026

'The Monolith' used in experiment 1 is an elongated quartz crystal weighing 3.3 kg and 35 cm in height. 

In experiment 1, the crystal was placed on a pedestal which had been installed months prior to the experiments, so it did not constitute a novelty for the chimpanzees.

Credit

Aden Kahr

In experiment 2, Sandy separated three crystals from a pile of pebbles; on the right is close-up view of the three separated crystals: quartz (right), pyrite (up), and calcite (bottom left).

Credit

García-Ruiz et al., 2026

Yvan analyzing transparency of crystals. [VIDEO]1 

Yvan analyzing transparency of crystals. [VIDEO] 2