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The growing urgency of fungal disease in crops

May 25, 2023 by IAPPS

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Address the growing urgency of fungal disease in crops

More political and public awareness of the plight of the world’s crops when it comes to fungal disease is crucial to stave off a major threat to global food security.

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A dark cloud of dust from smut surrounds a machine harvesting crops on a sunny day
Clouds of dust caused by a fungus engulf a crop field. Credit: Darren Hauck/Reuters

In October 2022, the World Health Organization (WHO) published its first list of fungal pathogens that infect humans, and warned that certain increasingly abundant disease-causing fungal strains have acquired resistance to known antifungals1. Even though more than 1.5 million people die each year from fungal diseases, the WHO’s list is the first global effort to systematically prioritize surveillance, research and development, and public-health interventions for fungal pathogens.

Yet fungi pose another major threat to human health — one that has received even less attention than infections in people.

Hundreds of fungal diseases affect the 168 crops listed as important in human nutrition by the Food and Agricultural Organization (FAO) of the United Nations. Despite widespread spraying of fungicides and the planting of cultivars bred to be more disease resilient, growers worldwide lose between 10% and 23% of their crops to fungal disease every year, and another 10–20% post-harvest2. In fact, the five most important calorie crops — rice, wheat, maize (corn), soya beans and potatoes — can be affected by rice blast fungus, wheat stem rust, corn smut, soybean rust and potato late blight disease (caused by a water mould oomycete), respectively. And losses from these fungi equate to enough food to provide some 600 million to 4,000 million people with 2,000 calories every day for one year3. Such losses are likely to increase in a warming world4,5.

Much more awareness of the plight of the world’s crops as a result of fungal disease is needed, as is more government and private- sector investment in crop fungal research.

Adaptive potential unleashed

In a 2019 list of 137 pests and pathogens (ranked according to impact), fungi dominate the first to sixth places for diseases affecting each of the world’s 5 most important calorie crops6. Wheat, for example, is grown over more land area than any other crop, with production yielding around 18% of all the calories consumed globally each year. Despite mitigation practices, current crop losses worldwide from infections by the Septoria tritici blotch disease-causing fungus Zymoseptoria tritici, the main wheat pathogen in temperate areas, range from 5% to 50%7. Losses caused by the wheat stem rust fungus Puccinia graminis, which frequents more tropical climates, range from 10% to 70% of the harvest3. Commodity crops, such as bananas and coffee, which in many countries generate revenue that is used to purchase calorie crops, are also vulnerable to fungal diseases.Bacterial defence repurposed to fight blight

Fungi are hugely effective pathogens. They produce massive amounts of spores. The spores of some species can persist in soil and remain viable for up to 40 years. In other species, airborne spores can disperse over distances ranging from a few metres to hundreds or even thousands of kilometres. Wheat stem rust, for example, produces airborne spores that can travel between continents8, although many other fungi produce prolific numbers of spores more locally, promoting disease spread within and between adjacent fields.

Fungi also exhibit a phenomenal degree of genetic variation and plasticity9. Over the past decade or so, genome-wide studies have revealed extensive genetic diversity between and within species of fungi. Although some fungal pathogens undergo frequent sexual recombination, genetic variation can be generated through other processes, too. These include mutational changes conferred by transposable elements (DNA sequences that can change their position in the genome), mitotic (asexual) recombination and the horizontal transfer of genetic material — in some cases, between fungal species, or between fungi and bacteria or plants.

A perfect storm

Current problems have arisen because the adaptability of fungi has met modern agricultural practices.

Most monocultures entail vast areas of genetically uniform crops. (The world’s largest monoculture is a field of more than 14,000 hectares of genetically uniform wheat in Canada.) These provide ideal feeding and breeding grounds for such a prolific and fast-evolving group of organisms. Added to this, the increasingly widespread use of antifungal treatments that target a single fungal cellular process (for example, compounds called azoles target an enzyme needed for the formation of fungal cell membranes) has led to the emergence of fungicide resistance.

Ever harder to control. A line chart showing the increase of antifungal use in agriculture leading to higher resistance.
Source: T. M. Heick et al. in Applied Crop Protection 2018 Ch. 4 (DCA, 2018)

Together, the azoles, the strobilurins and the succinate dehydrogenase inhibitors (all of which are single-target-site antifungals) comprise more than 77% of the global fungicide market10. Moreover, between 2021 and 2028, the market for fungicides is projected to grow by around 4.9% per year — largely thanks to increasing use in low-income countries.

An open question is how the impacts of fungal diseases on crops will be affected by climate change. Although little is known about the response of major plant pathogens to climate change, increasing temperatures in the Northern Hemisphere will drive the evolution of new temperature tolerances in fungal pathogens, and the establishment of pathogens that previously were restricted to more southerly regions4,5. In fact, since the 1990s, fungal pathogens have been moving polewards at around 7 km per year4. Growers have already reported wheat stem rust infections — which normally occur in the tropics — in Ireland and England.

Increasing temperatures might also affect interactions between plants and their microbiomes, including endophytic fungi (symbionts that live in plants). Harmless endophytic fungi could become pathogenic as plants change their physiologies in response to environmental stresses11, which has been demonstrated in studies of the model plant Arabidopsis thaliana12. Moreover, tolerance to higher temperatures in fungi could increase the likelihood of opportunistic soil-dwelling pathogens hopping hosts, and becoming pathogenic in animals or humans13.

With the pressures on the food system from a growing human population added to these problems — over the next 30 years, the global population is projected to grow to 9.7 billion — humanity is on track for unprecedented challenges to food production.

Early promise

Better protecting the world’s crops from fungal disease will require a much more unified approach than has been achieved so far — with closer collaboration between farmers, the agricultural industry, plant breeders, plant-disease biologists, governments and policymakers, even philanthropic funders.

It is no longer enough to focus on crop husbandry (such as the clearing or burning of diseased plant tissues), conventional methods of breeding plants for single disease-resistance genes, or the spraying of predominantly single-target-site fungicides. Growers and other stakeholders must exploit various technical innovations to more effectively monitor, manage and mitigate plant disease. Several approaches are already being developed or used to limit disease impacts and protect crop yields; in combination, these approaches could help farmers to sustain their yields in the coming decades.

Discovery and development of antifungals. The development of fungicides has been largely orchestrated in the agrochemical crop-protection industry. It has so far relied on the serendipitous discovery of antifungals following large-scale screening of compounds, such as the by-products of the pharmaceutical industry — and, since the 1980s, on the synthesis of chemical variants of known compounds, such as the strobilurins and the azoles.

However, it is time to move away from reliance on single-target-site fungicides, and to search for compounds that target multiple processes in the pathogen. In 2020, an inter-disciplinary research team at the University of Exeter, UK, revealed an interesting candidate molecule — a lipophilic cation (C18-SMe2+) that targets several fungal processes (including the synthesis of the energy-carrying molecule ATP, as well as programmed cell death)14. This molecule provides significant crop protection against Septoria tritici blotch in wheat, rice blast in rice13 and Panama TR4 disease in bananas15.

A close-up of corn smut in a field of corn
Corn smut, a disease caused by the fungus Ustilago maydis, affects maize (corn) crops.Credit: Getty

Increasing diversity in agricultural fields. Planting seed mixtures that combine several crop cultivars carrying different resistance genes could provide an important way to slow down pathogen evolution.

In 2022, around 25% of the total wheat production in Denmark used mixed cultivars, selected because they grow at a similar pace and carry complementary disease-resistance genes. This collaborative venture (involving breeders, farmers, environmentalists and scientists) provided promising results in terms of reducing the severity of both Septoria tritici blotch and yellow and brown rust in mixed cultivars without incurring yield loss (L. Nistrup Jørgensen, pers. comm.).

Indeed, these cultivars could reduce the spread of disease and the erosion of crop-resistance genes16.

Early disease detection and surveillance. Artificial intelligence (AI), satellites, remote- sensing tools (such as drones), incentives to persuade farmers to report disease and community-science projects that engage the public in the reporting of plant diseases (both in crops and in wild species) are beginning to engender more effective surveillance of fungal disease.

A collaborative scientist initiative called OpenWheatBlast aims to collect research outputs and data on the emerging wheat blast disease. The fast and easy data sharing allows discoveries to be made, resulting in faster disease control (see go.nature.com/42s25a3). Meanwhile, for the Cape Citizen Science project, an initiative funded by Stellenbosch University in South Africa, researchers are asking people who are interested in science to hunt for the oomycete Phytophthora spp. in South African vegetation (https://citsci.co.za/disease/) — to create records of the presence and spread of this pathogen.

Data collected through AI, community- science projects and so on could be integrated with disease records and collated into, for example, the PlantwisePlus programme (see go.nature.com/3mlgxnn) led by the Centre for Agricultural and Bioscience International, a non-profit intergovernmental organization. The results could also be integrated with climate data obtained from meteorological offices (for example, see go.nature.com/3ukk5hu) and so inform the building of models that predict when and where plant fungal diseases will occur5. More accurate disease predictions could, in turn, trigger early interventions to offset the loss of crops.

A biosecurity sign stands in front of a banana farm on an overcast day
A quarantined banana farm near Cairns in Queensland, Australia.Credit: Suzanne Long/Alamy

Disease resistance and plant immunity. Conventional plant-breeding practices have involved introducing into a given cultivar one or two genes that confer resistance to a particular disease, known as R genes. But although pathogens can overcome this R-gene-mediated resistance in a few years, it can take 10–20 years to go from researchers unmasking an R gene to an agriculture company selling the new cultivar. Incorporating two or more R genes (known as R-gene pyramiding or stacking) can broaden resistance to a diversity of pathogens. Yet field studies have documented how resistance achieved through this means can be short-lived17.

Most R genes encode proteins with a nucleotide-binding site and a leucine-rich repeat region, which act as receptors in the plant cell. These receptors recognize particular pathogen-produced molecules. However, plants possess an earlier detection system for pathogens, involving extracellular receptor proteins that recognize pathogen elicitor molecules, such as chitin and glucan. (Chitin and glucan are present in the fungal cell wall.) These receptors are known as pattern-recognition receptors (PRRs). This type of ‘immune boosting’ could be combined with new R-gene-edited cultivars or through R-gene pyramiding using conventional breeding to provide more durable and broader resistance to major pathogens.

A significant barrier to exploiting this approach in a way that is fast and efficient — particularly in Europe — is public and political resistance to the use of transgenic plants. In March, however, the UK Genetic Technology (Precision Breeding) Act was passed into law; this will enable the development and marketing of gene-edited crops in the United Kingdom. In principle, practices such as ‘immune boosting’, combined with the incorporation of two or more R genes into crops, could endow more durable and broader disease resistance.

Exploiting biologics and crop biotics. Biologics are a broad category of products derived from living organisms. Just as interest in probiotics in medicine has grown over the past decade, so too has interest in the use of biologics in crop protection. This is evidenced by the projected rise in investment by governments and stakeholders.

Strategies currently being explored include the exploitation of living antagonists of plant pathogens, such as the fungus Trichoderma spp., and spraying crops with natural antimicrobial compounds, such as polyoxins, which inhibit the synthesis of chitin (for example, polyoxin D zinc salt)18. Trichoderma strains can impede fungal phytopathogens either indirectly, for example by competing for nutrients and space, or directly, by parasitizing fungi. And in the past decade, researchers have identified other fungal and bacterial endophytes that can help to suppress disease.Indigenous knowledge is key to sustainable food systems

Plants do not grow alone — they associate with diverse microbial communities, which can play a part in plant development, stress tolerance and disease resistance. Over the past decade, new methods for profiling microbes have revealed the existence of beneficial microbial networks. The discovery that some microbial species always co-occur, whereas others never do, is essential knowledge in the design of consortia of microbes that can be applied to soil to promote plant growth and enhance disease protection. Indeed, the challenges ahead will include translating these discoveries from laboratory settings to fields of crops, and ensuring that synthetic, beneficial microbial communities persist once they are introduced, and do not adversely affect the native microbiota, or become pathogenic themselves18.

RNA trafficking between plants and fungi. In 2013, a research team showed that small RNAs (sRNAs) from the grey mould fungus Botrytis cinerea can silence plant host genes involved in immunity19. Some of the researchers then showed that double stranded RNAs (dsRNAs) and sRNAs from the fungus could protect vegetables and fruit against grey mould disease for up to ten days20. However, RNAs (usually encapsulated in tiny vesicles) are not only transferred from the fungus to the host — plant hosts also dispatch vesicles to suppress fungal virulence genes.

A growing number of researchers and newly founded technology companies are now looking to harness these naturally occurring RNA interference (RNAi) based trafficking systems to better protect crops against fungal disease. Currently, investigators are exploring two possible ways of using RNAs. One of these, called host-induced gene silencing or HIGS, relies on the genetic modification of crops. But this approach is lengthy, costly and can’t be implemented in the many countries where genetically modified plants remain banned. Therefore the main focus is now on spray-induced gene silencing or SIGS, in which sRNAs or dsRNAs are directly applied to plants, as a new, environmentally friendly and non-genetically modified crop-protection strategy21.

Several studies have documented the efficacy of RNAi in providing resistance to common fungal pathogens22. However, research is still needed to understand how these external RNAs are taken up and transported between the plant and fungal cells. Moreover, although progress is being made in the application of RNAs to crops, questions remain about the stability of the molecules.

A global body for plant health

Between January 2020 and January 2023, the UK Research and Innovation (UKRI) council allocated around US$686 million to COVID-19 research, and almost 225,000 papers on COVID-19 were published globally. (We conducted a search on the Scopus and Web of Science databases, using ‘COVID’ and ‘SARS-CoV-2’ as keywords.) During the same period, the UKRI spent around $30 million on fungal crop research and, globally, around 4,000 papers on crops and fungal disease were published. (Scopus and Web of Science key words were ‘crops’ and ‘fungal disease’.) Given that food security engenders health and well-being, agriculture and farmers are arguably just as crucial to human health as medicine and health-care providers.

Addressing the threat to human health posed by fungal crop diseases will require greater engagement with the problem, and more investment in research from governments, philanthropic organizations and private companies.

The International Plant Protection Convention (IPPC) is a body supported by the FAO that aims to protect the world’s plant resources from pathogens. It is much less well known than other bodies that deal with threats to human well-being, such as the WHO. The 180 member states that are signatories of the IPPC treaty must work together to change that.

Because viruses and bacteria dominate as agents of human disease, these microbes have received much more attention than have fungi. Yet in crops, fungi are by far the most important agents of disease. The WHO’s list of fungal pathogens that infect humans is a step towards bringing more attention to this extraordinary but understudied group of microbes. But addressing the greatest threats to food security — and so to human health — must include tending to the devastating impacts fungi are having, and will keep having, on the world’s food supply.

Nature 617, 31-34 (2023)

doi: https://doi.org/10.1038/d41586-023-01465-4

References

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Competing Interests

The authors declare no competing interests.

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Posted in Control tactics, Cultural control, Fungi, Host plant resistance, Pesticides | Leave a Comment »

France: Enhancing biocontrol

May 25, 2023 by IAPPS

Science16 May 2023 12:36 am AEST

Crop Pest Evolution Study May Enhance Biocontrol

https://4276c3b3807f224c7c6bf0fd7e7334cf.safeframe.googlesyndication.com/safeframe/1-0-40/html/container.html

INRAE – National Research Institute for Agriculture, Food and Environment

The Egyptian cotton leafworm (Spodoptera littoralis) is a pest species in France. It is found throughout the Mediterranean Basin as well as in Africa and the Middle East. Moth larvae are extremely polyphagous[1] and cause damage to diverse crop species (e.g., corn, legumes, cotton, tomatoes, peppers). As part of broader efforts to reduce pesticide levels, we must develop effective biocontrol methods. Such strategies often rely on disrupting reproduction and trapping moths using, most commonly, sex pheromones. However, pheromone synthesis is an expensive process, and it thus remains important to have other control strategies on hand. To this end, we need to improve our understanding of olfactory receptors in this moth.

In 2019, these research collaborators identified OR5, an olfactory receptor in the Egyptian cotton leafworm that recognises the main compound in the female sex pheromone blend. In this new study, the scientists explored the receptor’s evolutionary trajectory within Spodoptera to better characterise its functionality and specificity. They used a combined approach in which they resurrected ancestral receptors in the laboratory, with the help of computer analysis, and they modelled the 3D structure of the receptors. They were thus able to determine that OR5 appeared around 7 million years ago. The researchers also employed site-directed mutagenesis[2] to explore OR5’s genetic fine-tuning, which allowed them to identify the eight amino acids (AAs) behind the receptor’s high degree of specificity. This finding is particularly unexpected, given that past research on receptor evolution has suggested just one or two AA substitutions suffice to change the functionality of ecologically important receptors.

We must clarify how olfactory receptors emerge and acquire specificity over evolutionary time if we wish to anticipate the development of resistance to pheromone-based plant protection products. This research advances the above goal and, additionally, clarifies the function of OR5, a highly specific receptor that is essential in the reproduction of two Spodoptera species—the Egyptian cotton leafworm and the tobacco cutworm (S. litura). The latter occurs mostly in Asia and is also polyphagous. The discoveries detailed above will help spur the development of new biocontrol strategies that rely on (1) agonist molecules, which occupy receptors to the exclusion of the key pheromone compound, or (2) antagonist molecules, which block the receptor from being activated by the key pheromone compound.

This study arose from a collaboration between the Institute of Ecology and Environmental Sciences of Paris (iEES Paris; under the aegis of INRAE, Sorbonne University, CNRS, IRD, UPEC, and Paris Cité University) and the Chinese National Institute of Plant Protection. It was the fruit of the BiPi International Associated Laboratory.

[1]Polyphagous organisms feed on many different species

[2]Site-directed mutagenesis is a technique that introduces one or more precise mutations into a gene to study the functional impacts on the encoded protein.

/Public Release. This material from the originating organization/author(s) might be of the point-in-time nature, and edited for clarity, style and length. Mirage.News does not take institutional positions or sides, and all views, positions, and conclusions expressed herein are solely those of the author(s).View in full here.

Tags:3D, Africa, Asia, chinese, collaboration, Egypt, France, international, Mediterranean, Middle East, mutations, Paris, protection, reproduction, Scientists, university

Posted in Biological control, Pheromones | Leave a Comment »

USA: Reducing Fusarium Head Blight in Winter Barley

May 25, 2023 by IAPPS

USDA ARS Banner

Timing Matters When Reducing Fusarium Head Blight in Winter Barley

USDA Agricultural Research Service sent this bulletin at 05/15/2023 10:10 AM EDT

View as a webpage ARS News Service ARS News Service Timing Matters When Reducing Fusarium Head Blight in Winter Barley For media inquiries contact: Jessica Ryan, (301) 892-0085
May 15, 2023 When Fusarium head blight (FHB) threatens winter barley, the best time to apply a fungicide is about six days after full barley head emergence, according to a recent study published in Plant Disease. FHB, also known as scab, is a fungal disease that attacks small grains, discoloring the heads and contaminating the grain with the mycotoxin deoxynivalenol (DON), a toxic compound also known as vomitoxin. For barley, the most common grain used to make malt for beer and spirits, even a small amount of DON can cause crops to be rejected by purchasers. The disease in malted barley kernels may lead to gushing, or the rapid and uncontrolled foaming of beer, making the crop unusable for beer production. In a four-year study, researchers with the U.S. Department of Agriculture (USDA)’s Agricultural Research Service (ARS) and the University of Minnesota assessed three different fungicides for FHB reduction. The researchers evaluated the amount of DON present in mature winter barley heads following a fungicide application at one of three growth stages — half heading, full heading, and six days after full barley head emergence.  A stalk of healthy barley next to infected barley Healthy resistant barley (right) and susceptible barley shows symptoms of Fusarium head blight (left). (Photo by Brian Steffenson, University of Minnesota)  “The latest timing of fungicide application reduced DON significantly more than the early timing for all three fungicides tested in the study,”said Christina Cowger, small grains pathologist at ARS’s Plant Science Research Unit in Raleigh, North Carolina. “Applying fungicide before all heads were emerged did not significantly reduce DON in winter barley as compared to not spraying at all. If scab is threatening, growers should wait about six days after barley heads have all appeared before applying fungicide.” According to Cowger, eastern U.S. barley growers have two main tools for FHB management —plant moderately resistant varieties and apply a fungicide. By understanding the best timing for fungicide to minimize FHB, growers can manage high-FHB epidemic years and maximize profits from malting barley. FHB is one of the factors limiting the global production of barley since it can result in yield loss and economic damage. According to the American Phytopathological Society, the disease has cost U.S. wheat and barley farmers more than $3 billion since 1990. “Year in and year out, FHB is the disease that most threatens profitable wheat and barley production in the U.S.,” Cowger said. “Knowing how to get the most out of our FHB management tools is key to small grain profitability.” 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. Interested in reading more about ARS research? Visit our news archive U.S. DEPARTMENT OF AGRICULTURE
Agricultural Research Service

Posted in Crop protection, Fungi, Pesticides | Leave a Comment »

Invading insects are transforming Antarctic soils

May 24, 2023 by IAPPS

May 10, 2023

Study reveals that invading insects are transforming Antarctic soils

by British Antarctic Survey The midge is originally a native of South Georgia before arriving in Signy. Credit: Pete Bucktrout – BAS

A tiny flightless midge that has colonized Antarctica’s Signy Island is driving fundamental changes to the island’s soil ecosystem.

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Research by experts at the British Antarctic Survey (BAS) in collaboration with the University of Birmingham has revealed that a non-native midge species is significantly increasing rates of plant decomposition, resulting in three to five-fold increases in soil nitrate levels compared to sites where only native invertebrates occur.

The study, published in the journal Soil Biology and Biochemistry, was part of a Ph.D. project completed by Dr. Jesamine Bartlett jointly between Birmingham and BAS, and outlines how the midge, Eretmoptera murphyi, is altering soil ecosystems on the island. The insect is a decomposer, feeding on dead organic matter across the island which releases large amounts of nutrients into the soil.

Dr. Bartlett, lead author of the study, says, “Antarctic soils are very nutrient limited systems because decomposition rates are so slow. The nutrients are there, but it has taken this invasive midge to unlock them on Signy Island. It is an ‘ecosystem engineer’ in a similar way to earthworms in temperate soil systems.”

Eretmoptera murphyi, is a native of South Georgia—an island in the sub-Antarctic region. It was introduced to Signy Island by accident during a botany experiment in the 1960s, although its proliferation only became apparent during the 1980s. Prior to this, the only terrestrial sites on Signy with high nutrient levels were those associated with marine species coming ashore, for example penguin colonies and seal wallows.

The level of nitrates measured in soil colonized by Eretmoptera was comparable to that found close to seal wallows, despite the midge being only a few millimeters in size. This is because population densities of midge larvae can reach in excess of 20,000 individuals per m2 at some sites.

Spread by humans, mostly by hitching a ride on the soles of boots of researchers and tourists, the midge has gradually expanded the area it has colonized on the island. It can even survive in sea water for periods of time, leading to conjecture that it could eventually reach other islands.

Professor Peter Convey, a terrestrial ecologist at BAS, says, “A particular feature of the Antarctic is that it has had very few invading species so far and protecting this ecosystem is a very high priority. While at some level, there’s plenty of awareness of the implications of invading species, this research really highlights how the tiniest of animals can still have a hugely significant impact.”

The hostile Antarctic environment is a huge barrier to these invading species with very low temperatures, moisture, and nutrient availability. Alongside rising temperatures in the region, the nutrients released by the midges will start to allow more of these invaders.

Dr. Scott Hayward, an ecologist at the University of Birmingham and co-author, says, “The activity of the midges on Signy, in combination with climate change, potentially ‘opens the door’ for other species to become established which can further accelerate climate change. The midge has the capacity to survive in many Antarctic locations, so monitoring the spread and impacts on Signy is vital for our understanding of other Antarctic ecosystems.”

More information: Jesamine C. Bartlett et al, Ecological consequences of a single introduced species to the Antarctic: terrestrial impacts of the invasive midge Eretmoptera murphyi on Signy Island, Soil Biology and Biochemistry (2023). DOI: 10.1016/j.soilbio.2023.108965

Provided by British Antarctic Survey

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When ‘alien’ insects attack Antarctica

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Conserving biodiversity: Biocontrol for sustainable agriculture.

May 24, 2023 by IAPPS

May 22, 2023

Laura Hollis

Conserving biodiversity: biocontrol for sustainable agriculture

Can biocontrol help protect biodiversity? Biodiversity refers to all the living things on Earth, including how they interact with each other. A rich biodiversity means a healthy planet. 

A bee on tomato flowers
A bee on flowers of tomato crop. Image: Ajcespedes from Getty Images

However, biodiversity is in decline. The IPBES identified the main contributors to biodiversity loss as the changing use of the sea and land, direct exploitation of organisms, climate change, pollution and invasive species. 

PlantwisePlus is working to ensure the agricultural sector is part of a healthy landscape with clean water and air and healthy soils, where biodiversity is protected through sustainable approaches to crop pest and disease management.

Pests and diseases constantly threaten farmers’ crops. As a result, pesticides are often the first option when faced with an outbreak. The excessive and misuse of harmful chemicals is particularly damaging to biodiversity. As well as killing off target pests, chemicals also harm beneficial insects such as pollinators and natural enemies. 

PlantwisePlus recognises the urgent need to increase the uptake of lower-risk plant protection. As such, the programme promotes the use of low-risk plant protection solutions such as biological control (biocontrol).

Biocontrol uses living organisms such as natural enemies, predators, parasites or disease-causing organisms to reduce pest populations. Biocontrol is a sustainable and environmentally friendly alternative to chemical pesticides that is also economically efficient, as once natural enemies are established, they provide ongoing control without further cost or intervention.

There are three main types of biocontrol.

Classical biocontrol

Papaya mealybug on papaya fruit
Papaya mealybug on papaya fruit. Image: CABI

Classical biocontrol uses host-specific natural enemies from the pests’ region of origin to control the introduced non-native species. It is primarily used to control invasive species.

In Kenya, PlantwisePlus and partners are working to implement a classical biological control strategy to manage papaya mealybug (Paracoccus marginatus). The invasive pest has been devastating papaya crops in Kenya. A CABI study in 2019 found it caused an estimated 57% yield losses across five counties.

PlantwisePlus has been testing the efficacy of the parasitoid wasp, Acerophagus papayae, as a biological control agent. A parasitoid lives on or inside a host and always kills the host. In contrast, a parasite is an organism that lives in or on a host but does not kill the host.

The parasitoid wasp is native to the Americas and after host range testing in quarantine, researchers released A. papayae in the coastal counties of Mombasa, Kwale, and Kilifi in December 2021. The parasitoid is now established at these pilot sites and controlling the pest.

Find out more about the classical biocontrol strategy to control papaya mealybug.

Augmentative biocontrol

This form of biocontrol involves the mass production and periodic release of large numbers of biocontrol agents to control a pest. 

Fall armyworm on maize
Fall armyworm on maize. Image: CABI

PlantwisePlus has been working with partners in Pakistan to pilot mass production facilities for another parasitic belonging to the genus Trichogramma. Wasps belonging to this genus are commonly sold commercially worldwide, for augmentative biological control of various lepidopteran pests in agriculture and horticulture.

Conservation biocontrol

This form of biocontrol manages pests through the modification of the environment or existing practices to protect and enhance populations of specific natural enemies or other organisms.

CABI scientist Léna Durocher-Granger has been researching the biocontrol of fall armyworm (FAW) in Zambia. The team has identified 15 naturally occurring parasitoid species.

Maize farmers trialing intercropping with nectariferous plants
Maize farmers trialing intercropping with nectariferous plants © Léna Durocher-Granger

Studies have shown that these parasitoids attack up to 45% of the FAW eggs and larvae during the crop cycle. Intercropping maize with nectar-producing plants can help to increase the populations of these beneficial insects. These plants provide food and shelter for the insects, which helps them to survive and reproduce. As a result, there are more insects available to control the FAW population.  

Find out more about conservation biocontrol in Zambia.

CABI Bioprotection Portal

The CABI Bioprotection Portal is an open-access tool that enables users to discover information about registered biocontrol and biopesticide products around the world. Available online and offline, the CABI Bioprotection Portal helps growers and agricultural advisors to identify, source and correctly apply biocontrol and biopesticide products against problematic pests in their crops. The portal is accessible online and offline via smartphones, tablets and desktops.

Visit the CABI Bioprotection Portal

biocontrol, biodiversity, plant health

Agriculture and International Development, Crop health

Posted in Biological control, Sustainability | Leave a Comment »

Chinese research: Preventing spread of Brown marmorated stink bug in New Zealand

May 24, 2023 by IAPPS

Chinese research offers promise to prevent spread of Brown marmorated stink bug in New Zealand

Zespri International is funding research to understand the lifecycle of the brown marmorated stink bug (Halyomorpha halys) on organic and conventional kiwifruit in China, part of its native range. Now, Chinese scientists are making progress which could help prevent the brown marmorated stink bug spreading in New Zealand.

Dr Jin-ping Zhang, Senior Project Scientists based at CABI’s center in China, has also been busy testing the efficacy of a natural enemy for the brown marmorated stink bug; the parasitoid Asian Samurai Wasp (Trissolcus japonicus).

The brown marmorated stink bug is the kiwifruit industry’s second-most unwanted biosecurity threat after fruit flies; the risk of it entering New Zealand is considered extreme. Dr Zhang’s research has so far shown that brown marmorated stink bug egg periods optimum for parasitoid release are May to middle June and from early July to middle August. Dr Zhang adds that three continuous releases of the natural enemy in May was effective, for example, to control the first generation of eggs – therefore, keeping the fruit damage at a low level until the end of July.

Source: blog.invasive-species.org

Publication date: Wed 24 May 2023

Posted in Biological control, Emerging/invasive pests, Insects, Natural enemies | Leave a Comment »

Sustainable solution against Banana Panama Disease (TR4)

May 24, 2023 by IAPPS

Empowering growers with a sustainable solution against Banana Panama Disease (TR4)

Founded in 2016, Tropic emerged in the United Kingdom, with one mission: to address the unique challenges faced by farmers in tropical regions through cutting-edge genetic innovation. With coffee being its first crop, the team at Tropic soon turned their attention to one of the world’s most vital food sources: bananas.

In early 2017, Tropic became pioneers in the application of gene editing in bananas, positioning themselves at the forefront of the industry. They recognised that the biggest pain points for banana growers were the diseases that threaten the economic viability of banana cultivation and as a result jeopardised the availability of this essential food source for over 400 million people worldwide.

To this day, many farmers in the banana business are concerned that the industry as we know it will become a shadow of its former self in the coming decade unless a viable solution is identified.

Fight against the Banana Panama Disease
When it comes to the threat of the banana crop, there are two main diseases at hand – Banana Panama Disease, also known as TR4, and Black Sigatoka.

TR4, a soil-borne fungal pathogen, attacks the roots of banana plants, leading to their eventual demise. Infected fields typically suffer a significant reduction in yield, ranging from 20% to 40%, which poses a severe economic challenge for farmers for up to half a century.

Seeing this as an area that couldn’t be overlooked, the Tropic team developed a groundbreaking technology platform called GEiGS®.

Commenting on this, Tropic’s Chief Science Officer Eyal Maori says, “Our breakthrough technology platform, GEiGS®, is a game changer in the fight against diseases. By combining the benefits of RNAi with precise gene-editing, GEiGS® provides a unique and versatile platform that can be customised to address critical farming challenges such as viral, fungal, and pest diseases, without any yield penalties. It represents a major advancement in ensuring long-term crop health and sustainable agriculture.”

Originally created to combat TR4 in bananas, the GEiGS® technology has expanded beyond its initial purpose and Tropic. The solution is now under licence by other organisations, enabling them to address critical disease-related issues across a wide range of crops.

In the figure below, standard Cavendish varieties which were infected with TR4 and showing the distinct brown fungal growth. [top] some of Tropic’s resistant varieties which after being infected with the pathogen remain clear of the fungal growth.

Elimination
Looking ahead, Tropic has ambitious plans to expand its current field trials significantly in 2023. They aim to reach additional countries across Latin America and the Philippines, bringing the transformative power of GEiGS® to more farmers and communities. By doing so, Tropic strives to eradicate TR4 and other devastating diseases, heralding a new era of sustainable agriculture.


For more information:
Tropic
T: +44 (0)1603 274441
E: info@tropic.bio

Publication date: Wed 24 May 2023

Posted in Emerging/invasive pests, Fungi, Host plant resistance | Leave a Comment »

Pakistan: Low production likely as 30-40pc dates, mango hit by fungus

May 24, 2023 by IAPPS

The News International

Low production likely as 30-40pc dates, mango hit by fungus

By Our Correspondent

May 03, 2023

SUKKUR: About 30 to 40% of dates and mango products became victims of fungal affecting high production.Reports said that growers of the dates palm had submitted complaints of the mysterious diseases hitting their dates palm.

Reports said that a team of experts led by Abbas Ali Korai, Principal Scientist /Director (Nematology Research Institute, SHEC Mirpurkhas visited different areas of progressive growers of District Khairpur for observation.

They observed that out of 25 acres approximately 20-25 plants of date palm were affected by sudden decline disease due to rainwater during the monsoon season-2022.In mango orchards, approximately 10 per cent was affected by Gamosis due to the stagnant rainwater of the 2022 monsoon season. Citrus plants were planted on the boundary line of the mango orchard.

The date palm plants were found highly affected showing drying and wilt symptoms appearance, orange-yellowish colouring for the fronds’ midrib.The observers said that such symptom starts from outer-lower frond whorls toward central younger fronds.

Within a single frond, drying begins from the terminal part to cover the whole frond. Eventually, the entire frond turns to a pale brown hitting tree within a few months.“This always happens when irrigation water or rainwater standing in the field for about 1 to 3 months continuously and no proper drainage system after the rain. Intercropping is also a big source of disease.

The disease incidence% was recorded at the range of 5-30% at different spots. The experts of different lines visited the affected orchards of date palm and the preventive measures were also shared among the growers.”

The soil and affected product samples were collected from each field for the proper diagnosis and fertilizer requirements. Some specimens were brought to the mycological laboratory at Plant Disease Research Institute and processed for the isolation of causal pathogens.

Posted in Emerging/invasive pests, Fungi | Leave a Comment »

Florida USA: The Hibiscus Button Weevil (El Picudo del Botón del Hibisco)

May 24, 2023 by IAPPS

El Picudo del Botón del Hibisco (Anthonomus testaceosquamosus Linell, Coleoptera: Curculionidae)

Alexandra M Revynthi, German Vargas, Yisell Velazquez Hernandez, Paul E Kendra, Daniel Carrillo y Catharine M Mannion

Introducción

El picudo del botón del hibisco (Anthonomus testaceosquamosus Linell, Coleoptera: Curculionidae) es una plaga del hibisco (Hibiscus rosa-sinensis L., Malvales: Malvaceae), originaria del noroeste de México y sur de Texas, que fue visto en Florida por primera vez en mayo del 2017 (Skelley y Osborne 2018). El incremento de las poblaciones del picudo entre 2019 y 2020 impactó negativamente la industria del hibisco en el sur de Florida durante el periodo de empaque en la primavera, lo que resultó en grandes pérdidas económicas. Florida lidera la producción de hibisco a nivel nacional, donde la mayoría de la producción en viveros ocurre en el sur del estado. Aproximadamente entre el 20 y el 25% de las plantas vendidas en el condado de Miami-Dade son hibiscos, donde el valor del mercado de plantas ornamentales fue de 697 millones (precio en el vivero) en 2017 (Departamento de Agricultura de los Estados Unidos, 2017). El picudo del botón del hibisco es una plaga regulada por la División de Industria Vegetal del Departamento de Agricultura y Servicios al Consumidor (FDACS-DPI, por sus siglas en inglés). De acuerdo con esta designación, cualquier vivero que sea identificado con la presencia de la plaga debe firmar y seguir un acuerdo de cumplimiento con el FDACS-DPI para reducir las probabilidades de dispersión del picudo. El propósito de este documento es proveer información acerca de esta importante plaga a productores de viveros y al público interesado.

Identificación

El picudo del botón del hibisco (Orden Coleoptera) pertenece a la familia de los picudos (Curculionidae) y a su vez pertenece al grupo de especies conocido como Anthonomus squamosus de la tribu Anthonomini. Este grupo de especies se caracteriza por tener insectos predominantemente cubiertos de escamas (Clark et al. 2019) (Figura 1). La longitud del cuerpo del adulto está entre 2,5 y 2,7 mm y el pico es de aproximadamente 1 mm de largo.

Adulto de Anthonomus testaceosquamosus, a) vista lateral y b) vista dorsal.
Figura 1. Adulto de Anthonomus testaceosquamosus, a) vista lateral y b) vista dorsal.
Credit: Daniel Carrillo, UF/IFAS TREC

Las hembras se pueden distinguir de los machos mediante dos características, una es la protibia (el cuarto segmento del primer par de patas) y otra es el abdomen. En la protibia las hembras tienen un uncus apical y subapical, prominencia interior-marginal (mucron) (estructura en forma de espuela del lado interno de la tibia) (Figura 2a), que está ausente en los machos (Figura 2b). Adicionalmente, la parte posterior del quinto tergito abdominal (margen del quinto segmento abdominal) es recto en las hembras (Figura 3a, derecha) y curvo en los machos (Figura 3b, izquierda). La validez de estos caracteres fue confirmada mediante la disección de la genitalia de los picudos (Figura 4).

Protibia de la hembra (a) y del macho (b) de Anthonomus testaceosquamosus. La prominencia interior-marginal subapical (circulo; mucron) está presente en hembras, pero está ausente en machos.
Figura 2. Protibia de la hembra (a) y del macho (b) de Anthonomus testaceosquamosus. La prominencia interior-marginal subapical (circulo; mucron) está presente en hembras, pero está ausente en machos.
Credit: Daniel Carrillo, UF/IFAS TREC
a) Abdomen del macho y b) de la hembra de Anthonomus testaceosquamosus. La parte posterior del quinto tergito en las hembras es recto (a, flecha a la derecha) y es curvo en machos (b, flecha a la derecha). Las hembras (a, flecha a la izquierda) tienen un pequeño pigidio (última parte del cuerpo que está expuesto cuando los élitros están en reposo) en comparación con los machos (b, flecha a la izquierda).
Figura 3. a) Abdomen del macho y b) de la hembra de Anthonomus testaceosquamosus. La parte posterior del quinto tergito en las hembras es recto (a, flecha a la derecha) y es curvo en machos (b, flecha a la derecha). Las hembras (a, flecha a la izquierda) tienen un pequeño pigidio (última parte del cuerpo que está expuesto cuando los élitros están en reposo) en comparación con los machos (b, flecha a la izquierda).
Credit: Daniel Carrillo, UF/IFAS TREC
Genitalia a) de la hembra y b) del macho de Anthonomus testaceosquamosus.
Figura 4. Genitalia a) de la hembra y b) del macho de Anthonomus testaceosquamosus.
Credit: Daniel Carrillo, UF/IFAS TREC

Los huevos son blancos cuando están recién depositados y se tornan amarillos al madurar (Figura 5). Las larvas del picudo del hibisco son de un color entre transparente y amarillo, tienen una cápsula cefálica bien definida y están desprovistas de patas torácicas (Figura 6). El tamaño de las larvas varía con el tamaño de los botones florales en donde se encuentran. En general, los botones florales grandes contienen larvas de mayor tamaño.

Múltiples huevos son depositados por las hembras de Anthonomus testaceosquamosus en las anteras del hibisco y dentro del botón floral.
Figura 5. Múltiples huevos son depositados por las hembras de Anthonomus testaceosquamosus en las anteras del hibisco y dentro del botón floral.  
Credit: Juleysy Rodríguez y Yisell Velázquez Hernández, UF/IFAS TREC 
a) Instar temprano y b) tardío de Anthonomus testaceosquamosus alimentándose en polen.
Figura 6. a) Instar temprano y b) tardío de Anthonomus testaceosquamosus alimentándose de polen.  
Credit: Juleysy Rodríguez y Yisell Velázquez Hernández, UF/IFAS TREC 

Rango de hospederos y daño

Los picudos pertenecientes al grupo de Anthonomus squamosus están asociados con especies de plantas de las familias Asteraceae o Malvaceae. El picudo del botón del hibisco, A. testaceosquamosus ha sido asociado con múltiples especies de plantas, todas dentro de la familia Malvaceae (Tabla 1).

Tabla 1. Especies de plantas en las cuales el picudo del botón del hibisco Anthonomus testaceosquamosus Linell ha sido encontrado (Clark et al. 2019).

View

Los adultos del picudo se alimentan principalmente de botones florales, tallos y en menor medida de hojas del hibisco. Las hembras ovipositan en los botones florales y las larvas se desarrollan en el interior del botón, causando la caída de este antes de la floración. Los síntomas incluyen perforaciones en los tallos y botones a punto de abrir (Figura 7), y caída severa de botones bajo condiciones de alta densidad de la plaga. El daño producido por la alimentación en las hojas no es muy llamativo. En viveros del sur de Florida, las variedades rosadas y amarillas parecen ser más susceptibles al picudo que las rojas y otras variedades (Tabla 2). La variedad rosada ‘Painted Lady’ y la variedad amarilla ‘Sunny Yellow’ son reportadas como las variedades más susceptibles. La variedad roja ‘President Red’ es reportada como la más resistente.

Tabla 2. Variedades de hibisco cultivadas en Florida que han sido encontradas infestadas por el picudo del botón del hibisco (Anthonomus testaceosquamosus).

View

En Florida, otra especie del grupo Anthonomus squamosus, Anthonomus rubricosus, ha sido reportada infestando algodón y plantas de hibisco (Clark et al. 2019; Loiácono et al. 2003). Sin embargo, no existen reportes recientes de su establecimiento en plantas de hibisco en Florida. Este picudo es similar en tamaño al picudo del hibisco, pero es de color café. El genero Anthonomus incluye varias especies de gran importancia agrícola, como el picudo del algodonero, Anthonomus grandis. Las plagas del género Anthonomus más importantes desde el punto de vista económico en Florida son el picudo del chile Anthonomus eugenii y el picudo de la acerola Anthonomus macromalus. El picudo del chile ataca plantas de la familia Solanaceae, particularmente chiles (Capsicum spp.) (Capinera 2002), mientras que el picudo de la acerola ataca la cereza de Barbados (Malpighia glabra, Familia: Malpighiaceae) (Hunsberger y Peña 1998).

Daños causados por la alimentación de Anthonomus testaceosquamosus en hibisco a) botón floral con adulto del picudo y b) daño en peciolo.
Figura 7. Daños causados por la alimentación de Anthonomus testaceosquamosus en hibisco a) botón floral con adulto del picudo y b) daño en peciolo.
Credit: Juleysy Rodríguez y Yisell Velázquez Hernández, UF/IFAS TREC

La caída de los botones también puede ser causada por la mosquita de la flor (Contarinia maculipennis, Diptera: Cecidomyiidae), que puede ser confundida con daño por parte del picudo del botón del hibisco (Mannion et al. 2006). Ambas plagas pueden infestar la misma planta de hibisco; sin embargo, rara vez se encuentran en el mismo botón floral. Botones infestados con la mosquita de la flor tienen internamente múltiples larvas de mosca de color entre blanco y amarillo que saltan cuando son molestadas. Las larvas de la mosquita de la flor no tienen una cabeza distinguible y patas, y necesitan abandonar el botón para empupar en el suelo, mientras que la larva del picudo del hibisco tiene cabeza y empupa dentro del botón floral (Figuras 8 y 9).

a) Larva del picudo del botón del hibisco, Anthonomus testaceosquamosus y b) larva de la mosquita de la flor, Contarinia maculipennis.
Figura 8. a) Larva del picudo del botón del hibisco, Anthonomus testaceosquamosus y b) larva de la mosquita de la flor, Contarinia maculipennis.
Credit: Juleysy Rodríguez y Yisell Velázquez Hernández, UF/IFAS TREC
Larva de la mosquita de la flor (Contarinia maculipennis) saliendo del botón floral. La foto muestra el daño causado por la alimentación de las larvas en el botón floral.
Figura 9. Larva de la mosquita de la flor (Contarinia maculipennis) saliendo del botón floral. La foto muestra el daño causado por la alimentación de las larvas en el botón floral.
Credit: Juleysy Rodríguez y Yisell Velázquez Hernández, UF/IFAS TREC

Biología

Las hembras del picudo del botón del hibisco ovipositan entre 3 y 5 huevos en un solo botón floral y cerca de las anteras (Figura 4). Una vez que las larvas eclosionan se alimentan de polen y permanecen dentro del botón floral hasta alcanzar el estado adulto. Debido a una alta incidencia de canibalismo en el estado de larva, no todos los huevos depositados en un botón llegan al estado adulto; sin embargo, varios adultos pueden emerger de un solo botón floral. A una temperatura de 26,7 °C (8 0°F), los huevos pueden emerger entre 2 y 3 días. El estado de larva tiene tres instares y puede durar, en promedio, 10 días. El estado de pupa dura entre 2,9 a 4,2 días (Figura 10). El desarrollo entre el estado de huevo y el adulto puede tomar entre 12,8 y 15,3 días, en el cual se ha observado una sobrevivencia de hasta el 90%. La longevidad de los adultos tiene un rango entre 13 y 169 días, y los machos viven por más tiempo que las hembras. Cuando los adultos son alimentados solamente usando polen pueden sobrevivir hasta 52 días. Los adultos sobreviven un promedio de 28 días sin acceso a alimento, pero con acceso a agua, y pueden sobrevivir 16 días sin alimento y sin agua. La proporción sexual es de 1:1 hembras por machos (Revynthi et al. 2022).

Pupa de Anthonomus testaceosquamosus.
Figura 10. Pupa de Anthonomus testaceosquamosus.
Credit: Juleysy Rodríguez y Yisell Velázquez Hernández, UF/IFAS TREC

Temperaturas extremas ya sean bajas o altas parecen ser perjudiciales para el desarrollo de las larvas del picudo. En experimentos de laboratorio en la Universidad de Florida, a 10 °C (50 °F) no hubo eclosión de huevos, mientras que a 15 °C (59 °F) hubo eclosión 12 días luego de la oviposición, pero las larvas no se alimentaron y eventualmente murieron. De manera similar, a 38,8 °C (93 °F) los huevos eclosionaron luego de 5,6 días, pero ninguna larva llegó al estado de pupa (Revynthi et al. 2022). En el sur de Florida, el pico de actividad de este picudo ha sido observado desde marzo hasta junio con bajas poblaciones desde septiembre hasta febrero.

Desarrollo de técnicas de manejo de plagas y monitoreo

Los programas de manejo integrado de plagas dirigidos al picudo del botón del hibisco contienen una combinación de prácticas culturales, sanitización, control químico y control biológico. La rotación de cultivos con especies no hospederas ha sido recomendada para interrumpir los ciclos de población (Bográn et al. 2003). La sanitización incluye la recolección y destrucción sistemática de todos los botones caídos al suelo. A pesar de que la sanitización es una labor de alta demanda de mano de obra, ha sido propuesta como una de las prácticas más eficientes en el manejo de esta plaga puesto que evita la reinfestación de las plantas con nuevos adultos (Bográn et al. 2003). Actualmente no existen insecticidas registrados específicamente para el control del picudo del botón del hibisco en Florida, pero los cultivadores pueden usar legalmente insecticidas que están registrados para su uso en viveros. La FDACS-DPI tiene una lista de insecticidas recomendados para el control de esta plaga. Las pruebas de eficacia de varios insecticidas registrados para picudos/coleópteros y otras plagas especificas en plantas ornamentales están actualmente en desarrollo. Hasta la fecha no existen reportes de enemigos naturales del picudo del botón del hibisco, pero en la actualidad se está estudiando el potencial uso de hongos y de nematodos entomopatógenos como agentes de control biológico.

Varias especies dentro del género Anthonomus son atraídas hacia un grupo de atrayentes comerciales que consisten en feromonas de agregación del macho y compuestos volátiles vegetales (Tumlinson et al. 1969; Eller et al. 1994; Innocenzi et al. 2001). Existen cuatro componentes de la feromona sintética de agregación del macho, también conocidos como Grandlures (I-IV). En la actualidad se está estudiando el uso de trampas de feromonas utilizadas ampliamente en otras especies de Anthonomus, para el caso del picudo del botón del hibisco. En Texas, las trampas de feromonas desarrolladas para el picudo del algodonero (A. grandis) fueron evaluadas, sin éxito, en la captura de adultos del picudo del botón del hibisco (Bográn et al. 2003). Sin embargo, los autores plantean que esto pudo haber ocurrido ante una ubicación temprana de las trampas de acuerdo con la temporada de aparición de los adultos. Las trampas pegajosas amarillas son las trampas más atractivas para varias especies de Anthonomus (Cross et al. 2006; Szendrei et al. 2011; Silva et al. 2018). Actualmente se adelantan pruebas de campo que estudian el poder atrayente de las feromonas del picudo del algodonero (A. grandis) y del picudo del chile (A. eugenii), y para poder identificar el mejor tipo de trampa para capturar los adultos del picudo del botón del hibisco. Es necesario un programa de manejo integrado de plagas que implemente las estrategias mencionadas anteriormente para regular las poblaciones de A. testaceosquamosus en Florida y disminuir el impacto económico causado por esta especie.

Referencias

Bográn CE, Helnz KM, Ludwlg S (2003) The bud weevil Anthonomus testaceosquamosus, a pest of tropical hibiscus. In: SNA Research Conference Entomology. pp 147–149

Capinera, J. L. (2002). Pepper weevil Anthonomus eugenii Cano (Insecta: Coleoptera: Curculionidae). Featured Creatures, University of Florida EENY-278

Clark WE, Burke HR, Jones RW, Anderson RS (2019) The North American Species of the Anthonomus squamosus Species-Group (Coleoptera: Curculionidae: Curculioninae: Anthonomini). Coleopt Bull 73:773. https://doi.org/10.1649/0010-065X-73.4.773

Cross JV., Hesketh H, Jay CN, et al (2006) Exploiting the aggregation pheromone of strawberry blossom weevil Anthonomus rubi Herbst (Coleoptera: Curculionidae): Part 1. Development of lure and trap. Crop Prot 25:144–154. https://doi.org/10.1016/j.cropro.2005.04.002

Eller FJ, Bartelt RJ, Shasha BS, et al (1994) Aggregation pheromone for the pepper weevil, Anthonomus eugenii cano (Coleoptera: Curculionidae): Identification and field activity. J Chem Ecol 20:1537–1555. https://doi.org/10.1007/BF02059879

Hunsberger A, Pena JE (1998) Biodynamics of Anthonomus macromalus (Coleoptera : Curculionidae ), a weevil pest of Barbados Cherry in Florida. Florida Entomol 334–338

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Loiácono MS, Marvaldi AE, Lanteri AA (2003) Description of larva and new host plants for Anthonomus rubricosus Boheman (Coleoptera: Curculionidae) in Argentina. Entomol News 114:69–74

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Revynthi, A.M.; Velazquez Hernandez, Y.; Canon, M.A.; Greene, A.D.; Vargas, G.; Kendra, P.E.; Mannion, C.M. 2022. Biology of Anthonomus testaceosquamosus Linell, 1897 (Coleoptera: Curculionidae): A New Pest of Tropical Hibiscus. Insects. 13. https://doi.org/10.3390/insects13010013

Silva D, Salamanca J, Kyryczenko-Roth V, et al (2018) Comparison of trap types, placement, and colors for monitoring Anthonomus musculus (Coleoptera: Curculionidae) adults in highbush blueberries. J Insect Sci 18:. https://doi.org/10.1093/jisesa/iey005

Skelley PE, Osborne LS (2018) Pest Alert Anthonomus testaceosquamosus Linell, the hibiscus bud weevil, new in Florida. Gainesville

Szendrei Z, Averill A, Alborn H, Rodriguez-Saona C (2011) Identification and field evaluation of attractants for the cranberry weevil, Anthonomus musculus Say. J Chem Ecol 37:387–397. https://doi.org/10.1007/s10886-011-9938-z

Tumlinson JH, Hardee DD, Gueldner RC, et al (1969) Sex pheromones produced by male boll weevil: Isolation, identification, and synthesis. Science 166:1010–1012. https://doi.org/10.1126/science.166.3908.1010

United States Department of Agriculture U (2017) Market Value of Agricultural Products Sold Including Food Marketing Practices and Value-Added Products : 2017 and 2012 Census of Agriculture 2017. 275–302

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Publication #ENY-2069S

Date: 4/24/2023

Featured Creatures (en espanol)

Featured Creatures (en espanol)

Entomology and Nematology

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About this Publication

Este documento ENY-2069S, hace parte de la serie de Extensión del Departamento de Entomología y Nematología de la Universidad de la Florida, UF/IFAS. La fecha original de publicación es agosto de 2021. Por favor visite la página web de EDIS en https://edis.ifas.ufl.edu para la versión de soporte de esta publicación.

About the Authors

Alexandra M. Revynthi, Departamento de Entomología y Nematología, UF/IFAS Centro de Investigación y Educación Tropical; German Vargas, Departamento de Entomología y Nematología, UF/IFAS Centro de Investigación y Educación Tropical; Yisell Velazquez-Hernández, Departamento de Entomologia y Nematologia, UF/IFAS Centro de Investigacin y Educacioón Tropical; Paul E. Kendra, USDA ARS, Estación Experimental en Horticultura Subtropical; Daniel Carrillo, Departamento de Entomologia y Nematologia, UF/IFAS Centro de Investigación y Educación Tropical; y Catharine M Mannion, Departamento de Entomología y Nematología, UF/IFAS Centro de Investigación y Educación Tropical.

Contacts

  • Alexandra Revynthi

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Posted in Emerging/invasive pests, Insects | Leave a Comment »

Australia: Managing banana pests and diseases

May 24, 2023 by IAPPS

Media Release

Banana army poised to defend Aussie plantations

Publication date: 18 May 2023

Banana growers managing over 600 commercial banana properties along the east coast of Australia are being armed with an arsenal of tools to guard against significant pests and diseases through a $1.7M collaboration.

Delivered through Hort Innovation and led by the Australian Banana Growers’ Council, the surveillance and grower education program provides an array of tools to protect the $500 million banana industry and educate growers on how to recognise early disease symptoms and manage diseases more effectively. This has been through farm visits, workshops, grower groups and other resources such as videos that provide tips for detecting new infections.

Hort Innovation chief executive officer Brett Fifield said addressing the threat of significant banana diseases, as well improving grower capacity to manage them, is a critical priority for the banana industry.

“Research shows if Panama TR4 alone was to spread widely it would cost the Australian banana industry $5 billion over ten years. The challenge of having to deal with TR4 in combination with other significant banana diseases on a property would have an even more serious impact.”

TR4 is currently contained to Far North Queensland and the Northern Territory. It is considered the biggest threat to Australian banana growers. However, if left unchecked, there are a range of other pests and diseases that could be just as devastating to the banana industry and the communities it supports. Losses through on-farm management of leaf diseases (yellow Sigatoka and Leaf Speckle) run to tens of millions of dollars per year and, if Banana Bunchy Top Virus (BBTV) were to spread in Far North Queensland, losses have been estimated at $16-20 million per year.

“That is why the banana industry is investing its levies heavily into a suite of programs through Hort Innovation that reduce the spread and impact of pests and diseases and ensure any new incidents are picked up as quickly as possible,” Mr Fifield said.

Australian Banana Growers’ Council project leader Rosie Godwin said the goal of the surveillance and education project is to boost the banana industry’s ability to prevent, manage, and reduce the impact of biosecurity threats.

“The presence of Bunchy Top on a property, if left unchecked, can make a business unviable within 18 months. On top of that, Bunchy Top symptoms alongside heavy infestation of Leaf Spot and Leaf Speckle could mask symptoms of TR4 and reduce the efficacy of surveillance, detection and containment,” Dr Godwin said.

“By directly including growers and farm advisors in surveillance and biosecurity programs, we are supercharging our biosecurity efforts and increasing the likelihood of early detection. Banana growers know their own properties better than anyone else, so even a little bit of training goes a long way.”

Third-generation banana grower and ABGC director Andrew Serra, from Tolga in Far North Queensland, said the project provides growers with the tools they need to be on the front foot when it comes to protecting their property and the industry more broadly.

“The ABGC team provide invaluable surveillance and training for banana growers like myself. As far as I’m concerned, we have got more than enough to deal with when it comes to pests and diseases, particularly with TR4. If Banana Bunchy Top was detected in the major production areas of Far North Queensland on top of that, it could decimate our industry, let alone any other biosecurity threat not currently present in Australia.”

Mr Fifield will be speaking more about this project and other Hort Innovation investments for the banana industry at the Australian Banana Congress tomorrow at 8am.

Lauren Jones

Content Manager

Contact details

0427 140 765Send an email

Posted in Bacteria, Emerging/invasive pests, Fungi, Insects, Pests, Plant Pathogens, Viruses | Leave a Comment »

Rice disease ID: App identifies rice disease at early stages

May 23, 2023 by IAPPS

December 12, 2022

New app identifies rice disease at early stages

by David Bradley, Inderscience Credit: Unsplash/CC0 Public Domain

Rice is one of the most important food crops for billions of people but the plants are susceptible to a wide variety of diseases that are not always easy to identify in the field. New work in the International Journal of Engineering Systems Modelling and Simulation has investigated whether an application based on a convolution neural network algorithm could be used to quickly and effectively determine what is afflicting a crop, especially in the early stages when signs and symptoms may well be ambiguous.

Manoj Agrawal and Shweta Agrawal of Sage University in Indore, Madhya Pradesh, suggest that an automated method for rice disease identification is much needed. They have now trained various machine learning tools with more than 4,000 images of healthy and diseased rice and tested them against disease data from different sources. They demonstrated that the ResNet50 architecture offers the greatest accuracy at 97.5%.

The system can determine from a photograph of a sample of the crop whether or not it is diseased and if so, can then identify which of the following common diseases that affect rice the plant has: Leaf Blast, Brown Spot, Sheath Blight, Leaf Scald, Bacterial Leaf Blight, Rice Blast, Neck Blast, False Smut, Tungro, Stem Borer, Hispa, and Sheath Rot.

Overall, the team’s approach is 98.2% accurate on independent test images. Such accuracy is sufficient to guide farmers to make an appropriate response to a given infection in their crop and thus save both their crop and their resources rather than wasting produce or money on ineffective treatments.

The team emphasizes that the system works well irrespective of the lighting conditions when the photograph is taken or the background in the photograph. They add that accuracy might still be improved by adding more images to the training dataset to help the application make predictions from photos taken in disparate conditions.

More information: Shweta Agrawal et al, Rice plant diseases detection using convolutional neural networks, International Journal of Engineering Systems Modelling and Simulation (2022). DOI:

Posted in Diagnostics, Monitoring, Plant Pathogens | Leave a Comment »

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