Archive for the ‘Climate change’ Category

JANUARY 12, 2023

Review highlights a century of science in tackling emerging fungal diseases in response to climate change


Review highlights a century of science in tackling emerging fungal diseases in response to climate change
Dr David Smith examines CABI’s living culture collection of over 30,000 strains of fungi and bacteria including 5,000 plant pathogens and other microorganisms. Credit: CABI

A new CABI-led review published in the journal Microbiology Australia highlights how CABI has spent over 100 years identifying and combatting emerging fungal diseases of plants in response to the impacts of climate change.

Dr. David Smith, Emeritus Fellow and former Director, Biological Resources at CABI, led a team of scientists who focused on how climate change is influencing disease occurrence and how CABI’s work and resources can help in the battle to help reduce them.

Ultimately, the researchers highlight how CABI and its 49 Member Countries are working collaboratively with a global network of partners to manage emerging and spreading diseases which can affect livelihoods and impact upon food security.

This includes diseases such as Maize Lethal Necrosis Disease (MLND) which has been negatively affecting maize crops and their seeds in eastern and central Africa. Part of CABI’s work to help mitigate this included a project that sought to enhance the knowledge base on MLND viruses and the epidemiology of the disease in the affected countries.

A key component of CABI’s work in the field is its living culture collection. This was born from the establishment of the Imperial Bureau of Mycology in 1920 and laid the foundation of CABI’s expertise in mycology which continues to this day.

Currently there are over 30,000 strains of fungi and bacteria—including 5,000 plant pathogens and other microorganisms—in the collection of which 90% are unique to CABI. It represents one of the world’s largest genetic resource collections and holds the UK’s National Collection of Fungus Cultures.

Another aspect of CABI’s work is its Diagnostic and Advisory Service (DAS) which provides diagnostic advice on pests and diseases on crops from around the world. An example of this was the confirmation of the invasive apple snail (Pomacea canaliculate)—which threatens Kenya’s rice crops—using DNA analysis.

In addition to sequencing, techniques such as MALDI-TOF (matrix-assisted laser desorption ionization—time of flight analysis) are used are used to identify and characterize disease causing microorganisms.

Other recent new country reports of pests and diseases confirmed by the DAS laboratory include Moniliophthora roreri causing frosty pod rot on cocoa in Jamaica and the fall armyworm (Spodoptera frugiperda) which affects more than 100 plant species and is found in Africa and Asia.

Dr. Smith said, “An understanding of microbes and microbial communities is essential for improving crop yields and facilitating interventions, such as biocontrol of pests, diseases, and invasive species.

“In parallel to the scientific work, CABI information resources are supporting the science and fieldwork to increase the reach, application, and understanding of the science worldwide.”

“In carrying out its work, CABI has seen an impact on emerging disease due to climate change and has implemented programs to help farmers adapt to its impact.”

These programs include the global PlantwisePlus program which works closely with national agricultural advisory services to establish a global network of plant clinics, run by trained ‘plant doctors’.

Rural plant clinics, staffed by agricultural advisors trained through PlantwisePlus, receive diseased samples and provide a timely diagnosis and appropriate remedial advice.

The program has been introduced to 34 countries in Africa, Asia and the Americas, presented over 5,000 plant clinics, trained over 13, 200 plant doctors and reached over 54 million smallholder farmers.

Recommendations to farmers have resulted in halving the use of restricted chemicals, increasing yields by more than 20% and over 1.5 million farmers have improved food security.

Another program is the Pest Risk Information Service (PRISE) which, in sub-Saharan Africa, used earth observation environmental data and models on pest life cycles to create early-warning alerts and advice to farmers on the timely application of pest control products.

It has delivered pest alerts in Kenya, Ghana, Zambia and Malawi to over 1.8 million farmers since it began in 2017. SMS information was sent to 6,000 farmers in Kenya, for example, on the fall armyworm which resulted in 60% of the farmers reporting a change in their farming practices as a result.

Dr. Smith added, “It is clear that climate change exacerbates problems and broadens the scope and range of plant pests and invasive species by enabling organisms to grow in environments from which they have normally been excluded.”

“Predictive models and early warning systems are needed if we are to combat such problems, for which CABI’s information resources and dissemination systems can play a critical role.”

A CABI-led review in the Journal of Economic Entomology has already highlighted several management options for the fall armyworm after recent climatic models reveal that the pest is likely to itself in the southern parts of Europe including southern Spain, Italy, Portugal or Greece.

More information: David Smith et al, CABI’s 100 years in identifying and combating emerging fungal diseases in response to climate change, Microbiology Australia (2022). DOI: 10.1071/MA22054

Dirk Babendreier et al, Potential Management Options for the Invasive Moth Spodoptera frugiperda in Europe, Journal of Economic Entomology (2022). DOI: 10.1093/jee/toac089

Journal information: Journal of Economic Entomology 

Provided by CABI

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January 4, 2023 

Elizabeth King 

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East Africa’s bean industry adapts to climate change

Climate change is likely to have a severe impact on East Africa’s bean industry. Beans are a vital crop, with over 200 million people in Sub-Saharan Africa depending on them as their most important pulse.

Runner/butter beans growing
Runner beans (Phaseolus coccineus), also known as butter bean

The global challenges of climate change have significant impacts on agriculture, food and nutrition security, and livelihoods. Farmers face environmental degradation, increasingly extreme weather, and reduced access to natural resources. As a result, there is a need for new research to find innovative solutions to ensure a food-secure future.

Research-based solutions

Alliance Bioversity International and the International Center for Tropical Agriculture (CIAT) work with local, national, and multinational partners to deliver extensive programs. These programmes find research-based solutions to create sustainable, prosperous, and nourishing food systems and landscapes.

One example of this is the Pan Africa Bean Research Alliance (PABRA). In collaboration with the Kenya Agricultural and Livestock Research Organisation (KALRO), the University of Nairobi, and Egerton University, PABRA has researched and released over 550 new bean varieties across 31 countries. This includes 33 varieties in Kenya (as of June 2022).

These bean varieties help to address a range of consumer needs. Benefits include increased abiotic resistance to factors like heat, drought, cold, and low soil fertility, and increased biotic resistance to a range of pests and diseases. Some varieties also improve cooking and nutritional quality with higher zinc or iron levels. Others even increase product yield. As a result, they help to increase the competitiveness of bean markets by providing customers with improved products. This, in turn, contributes to economic growth.

Dried beans
A variety of dried legumes

The importance of beans

Beans are a vital crop across sub-Saharan Africa, with over 200 million people depending on beans as their most important pulse. This creates a vast demand for beans of between 750,000 and 1 million MT per year. As a result, beans are economically significant.

Beans are also nutritionally vital, providing protein, fibre, complex carbohydrates, vitamins, and micronutrients. Dry beans (Phaseolus vulgaris L.) are the second most important food crop, after maize, in Kenya.

Development of drought-tolerant bean varieties

For the last 2 years, East Africa has received below-average levels of rainfall during the rainy seasons.  70 million people face severe drought conditions. This is the worst drought on record for the Horn of Africa since 1981.

The impact on the agricultural sector across East Africa is significant. Hit particularly hard are the northern and eastern pastoral areas of Kenya and the southern and eastern parts of Ethiopia.

This has resulted in water shortages, rising fertiliser prices, loss of livestock, and crop failure. Consequently, crop varieties that are more resilient to increasingly frequent extreme weather conditions are vital.

These bean varieties help farmers adapt to these changing conditions. For example, PABRAs development of a drought-tolerant variety, the Nyota bean, has been hugely successful.

Released in 2017, it targeted semi-arid counties (which cover 70% of Kenya) including Machakos, Makueni, Narok, and Baringo in Kenya. This variety also matures quickly with a 70-75-day maturity period, whilst other varieties take 90-120 days. In addition, it cooks quickly and is rich in essential micronutrients, including zinc and iron.

bean industry adapts to climate change
Beans at a market

Beans and integrated crop management (ICM)

The Pan Africa Bean Research Alliance also takes this a step further by promoting integrated crop management (ICM) strategies in combination with planting improved bean varieties. They work closely with farmers through field demonstrations, exchange visits, and printed guidance materials to promote efficient, climate-smart agricultural practices. In this way, PABRA helps farmers to significantly increase yields and be more climate-resilient.

ICM technologies include cropping systems like rotation and intercropping, and the use of organic fertiliser to improve soil fertility. They also include water management practices like infield water harvesting techniques.

PABRA estimates that 6 million farmers (68% of which are women) are aware of, and use, ICM technologies to improve bean production. In addition, PABRA continues to research ICM to find new and improved solutions. One example is assessing the potential for beans to contribute to nitrogen fixation which in turn increases yields of subsequent cereal crops when in a rotation cropping system.

Beans and climate change

Climate change threatens bean production due to more frequent extreme weather events. Drought has particularly affected East Africa, and temperatures are expected to increase by 2.5°C between 2000 and 2050. This is likely to reduce bean-growing regions by 50%.

Meanwhile, some areas are experiencing excessive rain, for example, in Western areas of Kenya. These conditions, alongside other factors, drive the spread of pests and diseases. They affect the geographic distribution of pests and diseases, as well as the survival rate, migratory routes, and population sizes of pests and vectors.

It is therefore vital to continue researching and implementing climate-smart technologies and practices, like creating more tolerant and resilient crop varieties. As well as, by building the capacity of governments to operationalise key related policies, to create a food-secure future.

Further reading

If you would like to find more information on this subject, please see the links below:

Development and delivery of bean varieties in Africa: The Pan-Africa bean research alliance (PABRA) model’.

Integrated crop management’ – CABI.

‘Climate-smart agriculture’ – World Bank.

Pan-Africa Bean Research Alliance (PABRA)’ – Alliance Bioversity International and CIAT.



The CABI-led PlantwisePlus programme is financially supported by the Directorate-General for International Cooperation (DGIS), Netherlands; European Commission Directorate General for International Partnerships (INTPA, EU); the Foreign, Commonwealth & Development Office (FCDO), United Kingdom; the Swiss Agency for Development and Cooperation (SDC); the Australian Centre for International Agricultural Research (ACIAR); the Ministry of Agriculture of the People’s Republic of China (MARA)

Climate smart agricultureEast AfricaKenyabeansclimate change

Agriculture and International DevelopmentClimate change and biodiversityCrop healthFood and nutrition security

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Scientists Warn of Insects Damaging Plants at Unprecedented Levels

TOPICS:FossilsInsectPaleontologyUniversity Of Wyoming


Insect-Damaged Leaf Fossil

This fossil leaf from Wyoming’s Hanna Basin, about 54 million years old, shows damage by insects. Credit: Lauren Azevedo-Schmidt

Insects today are causing unprecedented levels of damage to plants, even as insect numbers decline, according to new research led by scientists from the University of Wyoming.

In the first-of-its-kind study, insect herbivore damage of modern-era plants was compared with that of fossilized leaves from as far back as the Late Cretaceous period, nearly 67 million years ago. The findings were recently published in the prestigious journal Proceedings of the National Academy of Sciences.

“Our work bridges the gap between those who use fossils to study plant-insect interactions over deep time and those who study such interactions in a modern context with fresh leaf material,” says the lead researcher, University of Wyoming Ph.D. graduate Lauren Azevedo-Schmidt, now a postdoctoral research associate at the University of Maine. “The difference in insect damage between the modern era and the fossilized record is striking.”

Azevedo-Schmidt conducted the research along with the University of Wyoming Department of Botany and Department of Geology and Geophysics Professor Ellen Currano, and Assistant Professor Emily Meineke of the University of California-Davis.

Lauren Azevedo-Schmidt Fossilized Plant Search

Lauren Azevedo-Schmidt searches for fossilized plants in Wyoming’s Hanna Basin in a deposit that is about 60 million years old. She and other researchers compared fossil leaves with modern samples and found higher rates of insect damage today. Credit: Lauren Azevedo-Schmidt

In the study, fossilized leaves with insect feeding damage from the Late Cretaceous through the Pleistocene era, a little over 2 million years ago, were examined. They were then compared with leaves collected from three modern forests by Azevedo-Schmidt. The detailed research looked at different types of damage caused by insects, finding marked increases in all recent damage compared to the fossil record.

“Our results demonstrate that plants in the modern era are experiencing unprecedented levels of insect damage, despite widespread insect declines,” wrote the scientists, who suggest that the disparity can be explained by human activity.

Although more research is necessary to determine the precise causes of increased insect damage to plants, the scientists say a warming climate, urbanization, and the introduction of invasive species likely have had a major impact.

“We hypothesize that humans have influenced (insect) damage frequencies and diversities within modern forests, with the most human impact occurring after the Industrial Revolution,” the researchers wrote. “Consistent with this hypothesis, herbarium specimens from the early 2000s were 23 percent more likely to have insect damage than specimens collected in the early 1900s, a pattern that has been linked to climate warming.”

But climate change doesn’t fully explain the increase in insect damage, they say.

“This research suggests that the strength of human influence on plant-insect interactions is not controlled by climate change alone but, rather, the way in which humans interact with the terrestrial landscape,” the researchers concluded.

Reference: “Insect herbivory within modern forests is greater than fossil localities” by Lauren Azevedo-Schmidt, Emily K. Meineke and Ellen D. Curran, 10 October 2022, Proceedings of the National Academy of Sciences.
DOI: 10.1073/pnas.2202852119

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Dormant microbes can ‘switch on’ to cope with climate change

Date:November 29, 2022Source:eLifeSummary:Dormant strains of bacteria that have previously adapted to cope with certain temperatures are switched back on during climatic change, according to a new report.Share:


Dormant strains of bacteria that have previously adapted to cope with certain temperatures are switched back on during climatic change, according to a report published today in eLife.

The results have important implications for predicting the impact of global warming on ecosystems.

Microbes are integral to ecosystem function, because of their key roles as pathogens, food sources and in nutrient recycling. To understand the profound impact of climate change on the function of different ecosystems, it is therefore necessary to study the microbial communities within them.

“Microbial communities can respond to warming in the short term by acclimation — developing unique traits to suit the environment — or through the longer term by adaptation, where they make evolutionary changes over many generations,” explains lead author Thomas Smith, Research Associate at the Georgina Mace Centre for the Living Planet, Imperial College London, UK. “But there is also a third mechanism, called species sorting, whereby the composition of the overall community — that is, which species are present — alters with changes in temperature. The importance of species sorting relative to acclimation and adaptation has not previously been explored in the context of microbial community responses to changing temperature. “

To address this, the team carried out a species sorting experiment, where they grew replicate soil bacteria communities collected from a single site at different temperatures ranging from 4°C to 50°C. They then measured the growth and metabolism of each isolated strain of bacteria across these different temperatures to determine their thermal performance, and studied the genetic sequences of isolated bacteria to see how temperature-response traits evolved over time.

They found that evolutionarily and functionally distinct communities emerged at each of the temperature conditions, driven by the resuscitation of microbial strains that had been inactive under previous environmental conditions. This suggests that — rather than new bacteria moving into a community to suit the new conditions — the parent community harbours multiple bacterial strains that are pre-adapted to survive at different temperatures and can switch on when their preferred temperature is reached. As a result, microbial communities in nature are likely to be able to respond rapidly to temperature fluctuations.

“Understanding the relative importance of acclimation, adaptation and species sorting in the assembly and turnover of microbial communities is key to determining how quickly they can respond to temperature changes. Until now, a mechanistic basis of these community-level responses had not been discerned ,” concludes senior author Thomas Bell, Professor of Microbial Ecology at the Georgina Mace Centre for the Living Planet, Imperial College London. “We have found that the resuscitation of functional diversity within a microbial community can allow the whole community to survive in response to temperature changes. Further studies on other microbial communities — such as those residing in water — will support more accurate predictions of the effects of climate change on different ecosystems.”

Story Source:

Materials provided by eLifeNote: Content may be edited for style and length.

Journal Reference:

  1. Thomas P Smith, Shorok Mombrikotb, Emma Ransome, Dimitrios – Georgios Kontopoulos, Samraat Pawar, Thomas Bell. Latent functional diversity may accelerate microbial community responses to temperature fluctuationseLife, 2022; 11 DOI: 10.7554/eLife.80867

Cite This Page:

eLife. “Dormant microbes can ‘switch on’ to cope with climate change.” ScienceDaily. ScienceDaily, 29 November 2022. <www.sciencedaily.com/releases/2022/11/221129112755.htm>.

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Entomologists issue warning about effects of climate change on insects

by University of Maryland

<img src="https://scx1.b-cdn.net/csz/news/800a/2022/entomologists-issue-wa-1.jpg&quot; alt="Entomologists issue warning about effects of climate change on insects" title="Climate change impacts on insects can be categorized into two major categories: Gradual long-term change and extreme events that will increase in frequency and severity, while interventions include formal mitigation of change through policy and public approaches which in turn help to reduce impacts in various ways. Credit: <i>Ecological Monographs
Climate change impacts on insects can be categorized into two major categories: Gradual long-term change and extreme events that will increase in frequency and severity, while interventions include formal mitigation of change through policy and public approaches which in turn help to reduce impacts in various ways. Credit: Ecological Monographs (2022). DOI: 10.1002/ecm.1553

In a new scientific review, a team of 70 scientists from 19 countries warned that if no steps are taken to shield insects from the consequences of climate change, it will “drastically reduce our ability to build a sustainable future based on healthy, functional ecosystems.”

Citing research from around the world, the team painted a bleak picture of the short- and long-term effects of climate change on insects, many of which have been in a state of decline for decades. Global warming and extreme weather events are already threatening some insects with extinction—and it will only get worse if current trends continue, scientists say. Some insects will be forced to move to cooler climes to survive, while others will face impacts to their fertility, life cycle and interactions with other species.

Such drastic disruptions to ecosystems could ultimately come back to bite people, explained Anahí Espíndola, an assistant professor of entomology at the University of Maryland and one of the paper’s co-authors.

“We need to realize, as humans, that we are one species out of millions of species, and there’s no reason for us to assume that we’re never going to go extinct,” Espíndola said. “These changes to insects can affect our species in pretty drastic ways.”

Insects play a central role in ecosystems by recycling nutrients and nourishing other organisms further up the food chain, including humans. In addition, much of the world’s food supply depends on pollinators like bees and butterflies, and healthy ecosystems help keep the number of pests and disease-carrying insects in check.

These are just a few of the ecosystem services that could be compromised by climate change, the team of scientists cautioned. Unlike mammals, many insects are ectotherms, which means they are unable to regulate their own body temperature. Because they are so dependent on external conditions, they may respond to climate change more acutely than other animals.

One way that insects cope with climate change is by shifting their range, or permanently relocating to places with lower temperatures. According to one study cited by Espíndola and other scientists, the ranges of nearly half of all insect species will diminish by 50% or more if the planet heats up 3.2°C. If warming is limited to 1.5°C—the goal of the global Paris Agreement on climate change—the ranges of 6% of insects will be affected.

Espíndola, who studies the ways in which species respond to environmental changes over time, contributed to the sections of the paper that address range shifts. She explained that drastic changes to a species’ range can jeopardize their genetic diversity, potentially hampering their ability to adapt and survive.

On the other hand, climate change may make some insects more pervasive—to the detriment of human health and agriculture. Global warming is expected to expand the geographical range of some disease vectors (such as mosquitoes) and crop-eating pests.

“Many pests are actually pretty generalist, so that means they are able to feed on many different types of plants,” Espíndola said. “And those are the insects that—based on the data—seem to be the least negatively affected by climate change.”

The team noted that the effects of climate change are often compounded by other human-caused impacts, such as habitat loss, pollution and the introduction of invasive species. Combined, these stressors make it more difficult for insects to adapt to changes in their environment.

Though these effects are already being felt by insects, it is not too late to take action. The paper outlined steps that policymakers and the public can take to protect insects and their habitats. Scientists recommended “transformative action” in six areas: phasing out fossil fuels, curbing air pollutants, restoring and permanently protecting ecosystems, promoting mostly plant-based diets, moving towards a circular economy and stabilizing the global human population.

The paper’s lead author, Jeffrey Harvey of the Netherlands Institute of Ecology (NIOO-KNAW) and Vrije Universiteit Amsterdam, said in a statement that urgent action is needed to protect insects and the ecosystems they support.

“Insects are tough little critters, and we should be relieved that there is still room to correct our mistakes,” Harvey said. “We really need to enact policies to stabilize the global climate. In the meantime, at both government and individual levels, we can all pitch in and make urban and rural landscapes more insect-friendly.”

The paper suggested ways that individuals can help, including managing public, private or urban gardens and other green spaces in a more ecologically-friendly way—for instance, incorporating native plants into the mix and avoiding pesticides and significant changes in land usage when possible.

Espíndola also stressed the value of encouraging neighbors, friends and family to take similar steps, explaining that it’s an easy yet effective way to amplify one’s impact.

“It is true that these small actions are very powerful,” Espíndola said. “They are even more powerful when they are not isolated.”

Their paper was published in Ecological Monographs.

More information: Jeffrey A. Harvey et al, Scientists’ warning on climate change and insects, Ecological Monographs (2022). DOI: 10.1002/ecm.1553

Provided by University of Maryland 

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Climate change means farmers in West Africa need more ways to combat pests

by Loko Yêyinou Laura Estelle, The Conversation

worm on corn
Credit: Unsplash/CC0 Public Domain

The link between climate change and the spread of crop pests has been established by research and evidence.

Farmers are noticing the link themselves, alongside higher temperatures and greater variability in rainfall. All these changes are having an impact on harvests across Africa.

Changing conditions sometimes allow insects and diseases to spread and thrive in new places. The threat is greatest when there are no natural predators to keep pests in check, and when human control strategies are limited to the use of unsuitable synthetic insecticides.

Invasive pests can take hold in a new environment and cause very costly damage before national authorities and researchers are able to devise and fund ways to protect crops, harvests and livelihoods.

Early research into biological control methods (use of other organisms to control pests) shows promise for safeguarding harvests and food security. Rapid climate change, however, means researchers are racing against time to develop the full range of tools needed for a growing threat.

The most notable of recent invasive pests to arrive in Africa was the fall armyworm, which spread to the continent from the Americas in 2016.

Since then, 78 countries have reported the caterpillar, which attacks a range of crops including staples like maize and has caused an estimated US$9.4 billion in losses a year.

African farmers are still struggling to contain the larger grain borer, or Prostephanus truncatus Horn, which reached the continent in the 1970s. It can destroy up to 40% of stored maize in just four months. In Benin, it is a particular threat to cassava chips, and can cause losses of up to 50% in three months.

It’s expected that the larger grain borer will continue to spread as climatic conditions become more favorable. African countries urgently need more support and research into different control strategies, including the use of natural enemies, varietal resistance and biopesticides.

My research work is at the interface between plants, insects and genetics. It’s intended to contribute to more productive agriculture that respects the environment and human health by controlling insect pests with innovative biological methods.

For example, we have demonstrated that a species of insect called Alloeocranum biannulipes Montr. and Sign. eats some crop pests. Certain kinds of fungi (Metarhizium anisopliae and Beauveria bassiana), too, can kill these pests. They are potential biological control agents of the larger grain borer and other pests.

Improved pest control is especially important for women farmers, who make up a significant share of the agricultural workforce.

In Benin, for example, around 70% of production is carried out by women, yet high rates of illiteracy mean many are unable to read the labels of synthetic pesticides.

This can result in misuse or overuse of chemical crop protection products, which poses a risk to the health of the farmers applying the product and a risk of environmental pollution.

Moreover, the unsuitable and intensive use of synthetic insecticides could lead to the development of insecticide resistance and a proliferation of resistant insects.

Biological alternatives to the rescue

Various studies have shown that the use of the following biological alternatives would not only benefit food security but would also help farmers who have limited formal education:

  1. Natural predators like other insects can be effective in controlling pests. For example I found that the predator Alloeocranum biannulipes Montr. and Sign. is an effective biological control agent against a beetle called Dinoderus porcellus Lesne in stored yam chips and the larger grain borer in stored cassava chips. Under farm storage conditions, the release of this predator in infested yam chips significantly reduced the numbers of pests and the weight loss. In Benin, yams are a staple food and important cash crop. The tubers are dried into chips to prevent them from rotting.
  2. Strains of fungi such as Metarhizium anisopliae and Beauveria bassiana also showed their effectiveness as biological control agents against some pests. For example, isolate Bb115 of B. bassiana significantly reduced D. porcellus populations and weight loss of yam chips. The fungus also had an effect on the survival of an insect species, Helicoverpa armigera (Hübner), known as the cotton bollworm. It did this by invading the tissues of crop plants that the insect larva eats. The larvae then ate less of those plants.
  3. The use of botanical extracts and powdered plant parts is another biological alternative to the use of harmful synthetic pesticides. For example, I found that botanical extracts of plants grown in Benin, Bridelia ferruginea, Blighia sapida and Khaya senegalensis, have insecticidal, repellent and antifeedant activities against D. porcellus and can also be used in powder form to protect yam chips.
  4. My research also found that essential oils of certain leaves can be used as a natural way to stop D. porcellus feeding on yam chips.
  5. I’ve done research on varietal (genetic) resistance too and found five varieties of yam (Gaboubaba, Boniwouré, Alahina, Yakanougo and Wonmangou) were resistant to the D. porcellus beetle.

Next generation tools

To develop efficient integrated pest management strategies, researchers need support and funding. They need to test these potential biocontrol methods and their combinations with other eco-friendly methods in farm conditions.

Investing in further research would help to bolster the African Union’s 2021–2030 Strategy for Managing Invasive Species, and protect farmers, countries and economies from more devastating losses as climate change brings new threats.

Initiatives like the One Planet Fellowship, coordinated by African Women in Agricultural Research and Development, have helped further the research and leadership of early-career scientists in this area, where climate and gender overlap.

But much more is needed to unlock the full expertise of women and men across the continent to equip farmers with next generation tools for next generation threats.

Provided by The Conversation 

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Why African farmers should balance pesticides with other control methods

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Now, an international team of experts is providing a convincing overview of the role of climate change and climatic extremes in driving insect decline.


Insects need urgent help to survive climate change

ByKatherine Bucko

Earth.com staff writer

While the scientific community has previously warned about an alarming decline in insect populations, not much has been done to address this issue on a global scale. Now, an international team of experts is providing a convincing overview of the role of climate change and climatic extremes in driving insect decline. 

“If no action is taken to better understand and reduce the impact of climate change on insects, we will drastically limit our chances of a sustainable future with healthy ecosystems.” This is the warning from a paper composed by 70 scientists from 19 countries around the world as part of the of the Scientists’ Warning series. 

“Climate change aggravates other human-mediated environmental problems,” said lead author Jeffrey Harvey from the Netherlands Institute of Ecology. “Including habitat loss and fragmentation, various forms of pollution, overharvesting and invasive species.”

Insects play critical roles in many ecosystems, making this problem incredibly urgent, as ecosystem loss is on the rise.

“The gradual increase in global surface temperature impacts insects in their physiology, behaviour, phenology, distribution and species interactions. But also, more and longer lasting extreme events leave their traces,” said Harvey.

While fruit flies, butterflies and flour beetles have the capacity to survive heat waves, they can become sterilized and unable to reproduce. Bumblebees, in particular, are very sensitive to heat, and climate change is now considered the main factor in the decline of several North American species.

“Cold-blooded insects are among the groups of organisms most seriously affected by climate change, because their body temperature and metabolism are strongly linked with the temperature of the surrounding air,” said Harvey.

Insects also play a critical role in supporting the global economy through services such as pollination, pest control, nutrient cycling and decomposition of waste. These vitally important services help to sustain humanity and provide billions of dollars annually to the global economy. 

“The late renowned ant ecologist Edward O. Wilson, once argued that ‘it is the little things that run the world’. And they do!’” said Harvey.

The ability for insects to adapt to global warming is further impacted by human threats such as habitat destruction and pesticides. Heatwaves and droughts can drastically harm insect populations in the short term, making insects less able to adapt to more gradual warming.  

The paper includes solutions and management strategies. Individuals can help by caring for different wild plants, providing food and shelter for insects during climate extremes. Reducing the use of pesticides and other chemicals is also recommended. 

“Insects are tough little critters and we should be relieved that there is still room to correct our mistakes,” said Harvey. “We really need to enact policies to stabilise the global climate. In the meantime, at both government and individual levels, we can all pitch in and make urban and rural landscapes more insect-friendly.”

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

By Katherine BuckoEarth.com Staff Writer

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Insects have a weak capacity to adjust their critical thermal limits. Sam England, Author provided (no reuse)

Insects will struggle to keep pace with global temperature rise – which could be bad news for humans

Published: October 3, 2022 11.01am EDT


  1. Hester WeavingPhD Candidate in Entomology, University of Bristol

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Hester Weaving receives funding from a BBSRC studentship.


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Animals can only endure temperatures within a given range. The upper and lower temperatures of this range are called its critical thermal limits. As these limits are exceeded, an animal must either adjust or migrate to a cooler climate.

However, temperatures are rising across the world at a rapid pace. The record-breaking heatwaves experienced across Europe this summer are indicative of this. Heatwaves such as these can cause temperatures to regularly surpass critical thermal limits, endangering many species.

In a new study, my colleagues and I assessed how well 102 species of insect can adjust their critical thermal limits to survive temperature extremes. We found that insects have a weak capacity to do so, making them particularly vulnerable to climate change.

The impact of climate change on insects could have profound consequences for human life. Many insect species serve important ecological functions while the movement of others can disrupt the balance of ecosystems.

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How do animals adjust to temperature extremes?

An animal can extend its critical thermal limits through either acclimation or adaptation.

Acclimation occurs within an animal’s lifetime (often within hours). It’s the process by which previous exposure helps give an animal or insect protection against later environmental stress. Humans acclimate to intense UV exposure through gradual tanning which later protects skin against harmful UV rays.

One way insects acclimate is by producing heat shock proteins in response to heat exposure. This prevents cells dying under temperature extremes.

A ladybird drinking a speck of water on a narrow leaf.
Insects in warmer environments develop fewer spots to reduce heat retention. mehmetkrc/Shutterstock

Some insects can also use colour to acclimate. Ladybirds that develop in warm environments emerge from the pupal stage with less spots than insects that develop in the cold. As darker spots absorb heat, having fewer spots keeps the insect cooler.

Adaptation occurs when useful genes are passed through generations via evolution. There are multiple examples of animals evolving in response to climate change.

Over the past 150 years, some Australian parrot species such as gang-gang cockatoos and red-rumped parrots have evolved larger beaks. As a greater quantity of blood can be diverted to a larger beak, more heat can be lost into the surrounding environment.

A colourful red-rumped parrot perched on a branch.
The red-rumped parrot has evolved a larger beak to cope with higher temperatures. Alamin-Khan/Shutterstock

But evolution occurs over a longer period than acclimation and may not allow critical thermal limits to adjust in line with the current pace of global temperature rise. Upper thermal limits are particularly slow to evolve, which may be due to the large genetic changes required for greater heat tolerance.

Research into how acclimation might help animals survive exceptional temperature rise has therefore become an area of growing scientific interest.

A weak ability to adjust to temperature extremes

When exposed to a 1℃ change in temperature, we found that insects could only modify their upper thermal limit by around 10% and their lower limit by around 15% on average. In comparison, a separate study found that fish and crustaceans could modify their limits by around 30%.

But we found that there are windows during development where an insect has a greater tolerance towards heat. As juvenile insects are less mobile than adults, they are less able to use their behaviour to modify their temperature. A caterpillar in its cocoon stage, for example, cannot move into the shade to escape the heat.

Exposed to greater temperature variations, this immobile life stage has faced strong evolutionary pressure to develop mechanisms to withstand temperature stress. Juvenile insects generally had a greater capacity for acclimating to rising temperatures than adult insects. Juveniles were able to modify their upper thermal limit by 11% on average, compared to 7% for adults.

But given that their capacity to acclimate is still relatively weak and may fall as an insect leaves this life stage, the impact is likely to be limited for adjusting to future climate change.

What does this mean for the future?

A weak ability to adjust to higher temperatures will mean many insects will need to migrate to cooler climates in order to survive. The movement of insects into new environments could upset the delicate balance of ecosystems.

Insect pests account for the loss of 40% of global crop production. As their geographical distribution changes, pests could further threaten food security. A UN report from 2021 concluded that fall armyworm populations, which feed on crops such as maize, have already expanded their range due to climate change.

A damaged corn crop following an attack by fall armyworms.
The fall armyworm is a damaging crop pest which is spreading due to climate change. Alchemist from India/Shutterstock

Insect migration may also carry profound impacts on human health. Many of the major diseases affecting humans, including malaria, are transmitted by insects. The movement of insects over time increases the possibility of introducing infectious diseases to higher latitudes.

There have been over 770 cases of West Nile virus recorded in Europe this year. Italy’s Veneto region, where the majority of the cases originate, has emerged as an ideal habitat for Culex mosquitoes, which can host and transmit the virus. Earlier this year, scientists found that the number of mosquitoes in the region had increased by 27%.

Insect species incapable of migrating may also become extinct. This is of concern because many insects perform important ecological functions. Three quarters of the crops produced globally are fertilised by pollinators. Their loss could cause a sharp reduction in global food production.

The vulnerability of insects to temperature extremes means that we face an uncertain and worrying future if we cannot curb the pace of climate change. A clear way of protecting these species is to slow the pace of climate change by reducing fossil fuel consumption. On a smaller scale, the creation of shady habitats, which contain cooler microclimates, could provide essential respite for insects facing rising temperatures.

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Scientists warn of ‘insect apocalypse’ amid climate change

insect egg
Credit: CC0 Public Domain

An emerging “insect apocalypse” will have radical effects on the environment and humankind, an Australian scientist has warned.

An international study on the future of insects under climate change scenarios has found the loss of insects will drastically reduce the ability of humankind to build a sustainable future.

Co-author William Laurance, of James Cook University in Australia, said the biosphere had already warmed by about 1.1 degrees Celsius since industrialization. It is projected to warm a further 2–5 degrees Celsius by 2100 unless greenhouse gas emissions are significantly reduced.

An insect’s small body size and inability to regulate their own body temperature made them particularly susceptible to changing temperature and moisture levels, Laurance said in a Tuesday statement.

“A growing body of evidence shows many populations of insects are declining rapidly in many places. These declines are of profound concern, with terms like an emerging ‘insect apocalypse’ being increasingly used by the media and even some scientists to describe this phenomenon,” Laurance said.

“The loss of insects works its way up the food chain, and may already be playing an important role in the widespread decline of their consumers, such as insect-eating birds in temperate environments.”

Insects are important parts of biodiversity and provide services to the wider environment—including pollination, pest control and nutrient recycling—all of which are beneficial to other creatures, including humans, Laurance said.

The study found climate change amplified the effects of other factors threatening insect populations, such as pollution, habitat loss and predation.

“It’s essential to manage and restore habitats that make them as ‘climate-proof’ as possible and enable insects to find refuges in which they can ride out extreme climatic events,” Laurance said.

“The evidence is clear and striking. We need to act now to minimize impacts on insect populations—we know how to do it, but the decision making and requisite funding keep getting pushed down the road,” Laurance added.

2022 dpa GmbH.

Distributed by Tribune Content Agency, LLC.

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Heightened weed burden could mean growers need to replace inundated crops

24 Oct 2022


Frontdesk / Arable

As a result of the summer’s prolonged drought, some early-drilled winter wheats are facing a heightened weed burden after the dry conditions have prevented pre-emergence herbicides from working effectively. That’s according to Mike Thornton, head of crop production for agronomy firm ProCam, who urges growers to assess affected fields to determine if the current crop should be retained or sprayed off and re-drilled.

 “Despite being a distant memory, the summer’s dry and hot conditions are still having an effect on the new cycle of cereal crops,” Mr Thornton explains. “Some wheats which were drilled ahead of schedule or on lighter land have suffered from a lack of soil moisture, which has prevented soil-acting pre-emergence herbicides from working to the best of their ability. As a result, some winter cereals are currently facing heightened competition from out-of-control weeds which, in the most severe cases, could threaten the crop’s viability and profitability.”

 Mr Thornton therefore recommends that each field should be assessed on a case-by-case basis to decide if the current crop, or part of it, should be sprayed off and re-drilled, either with a replacement winter crop, or with a subsequent spring crop.

 “Where the weed burden is excessive or contains difficult-to-control competitors such as black-grass, ryegrass and brome, it could be quite an easy decision to make. For example, if grass weeds have made it to the two-leaf stage or beyond, they will be very difficult to control as most contact herbicides have been rendered ineffective by mounting resistance.

 “In the most severe cases, it will make sense to admit defeat sooner rather than later and to write-off the current crop so that weeds can be burned off ahead of a replacement crop being established.”

 For many growers, Mr Thornton says it’s still not too late to get a replacement winter crop into the ground. For others, deferring to a spring-sown cropping strategy might be the better option.

 “In both cases, growers should be aware of the restrictions imposed by certain active ingredients on replacement crops. The best approach is to seek definitive advice from your agronomist and, where necessary, to implement a ‘plan B’ sooner rather than later.”

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October 14, 2022 

Cambria Finegold 

World Food Day: How can data science and modelling help smallholders adapt to climate change?

By Cambria Finegold, Global Director Digital Development, CABI 

Data science and modelling are relatively new concepts when it comes to farming. For centuries, smallholders have carefully passed down agricultural skills from generation to generation. They depended on this knowledge. And stable seasons and weather meant this information remained relevant for years. 

However, climate change has brought with it erratic conditions. New scenarios are forcing family farmers to abandon the techniques they have shared. Unexpected droughts, floods and changes in temperature destroy their crops. But they lack the knowledge to address the unpredictability. 

For example, in a +2°C environment, aphids can reproduce an extra five generations each year. The pest problems that smallholders face are becoming overwhelming. How do they adapt to a rapidly changing and unstable environment? Digital technology is helping to answer this question. 

The benefits of data science and modelling 

Data science and modelling offer a solution. These dynamic new fields in agricultural technology are helping farmers to adapt. As climate change contributes to an increasingly uncertain future, they support decision-making. They show how environments are changing and how pests are spreading. But they also reveal how to address these problems. 

From managing invasive species to strengthening plant health systems, high-quality data helps farmers. It can advise them on pest management, crop and variety choices, and the timing of agricultural tasks. Data modelling supports decisions that farmers must make around all of these things. 

Furthermore, data science and modelling help smallholders make more sustainable farming choices, for example, decisions around natural, sustainable pest control. Farmers can use technology to address climate change and protect the environment simultaneously. 

At the heart of this technology are predictive models. These models help smallholders understand what might happen – tools to navigate uncertainty. What happens in a cooler or warmer year? What agricultural practices can they employ to protect crops from drought or flood? What must they do today to safeguard tomorrow? 

Data science and modelling can make a big difference to smallholders. Farmers face conditions that do not make sense to them anymore. Technology can help guide them through the uncertainty. 

PRISE and data science and modelling 

One concrete example of this is the Pest Risk Information SErvice (PRISE). It is an early-warning information system that provides farmers with alerts. These alerts notify the farmers of the best times to take action to protect their crops. The service builds resilience to climate shocks by supporting preventative measures.  Since 2017, the service has reached over 1.8 million farmers in Ghana, Kenya, Malawi and Zambia. 

PRISE is showing remarkable success. The service held a phone survey following the 2019-20 short rains season in Kenya. It focused on smallholders receiving alerts about the fall armyworm pest. And it showed that 60% of smallholders reported changing their farming practices based on the alerts’ recommendations.  

The PRISE consortium is examining how it can expand from its focus on plant pests. Could it grow to a risk warning system that delivers information about weather risks? Can it expand to include a strong climate change angle? 

Using a data science and modelling in hybrid advisory services 

While technology is important, we must also combine it with on-the-ground support. Once a farmer has received new information, they will often need help implementing it. Hybrid approaches that combine technology with face-to-face advice are often more effective than digital-only approaches. For this reason, we must invest in agricultural advisory services

How we deliver information is essential. Farmers might be dismissive of advice given over text messages. Or the service might provide the recommendations in the farmer’s second language and might, therefore, be unclear. Agricultural advisory services can discuss any question the farmer has. They can support the move from traditional information delivery to technology. They can help to manage the perceived risks that farmers might have. 

Data science and modelling have a vital role to play in modern farming. They can help smallholders to grow more crops and safeguard their livelihoods. And they can help them adapt to climate change. Technology can provide solutions when traditional systems no longer give the farmers the answers they need. It provides a little more certainty in an uncertain world. 

Data scienceFood securityPRISEWorld Food Daymodeling

Agriculture and International Development

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