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Archive for the ‘Biological control’ Category

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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Potential use of entomopathogenic and mycoparasitic fungi against powdery mildew in aquaponics

Aquaponics has the potential to produce sustainable and accessible quality food through the integration of hydroponics and aquaculture. Plants take up dissolved nutrients in fish wastewater, allowing water reuse for fish. However, the simultaneous presence of fish and plants in the same water loop has made phytosanitary treatments of diseases such as powdery mildew problematic due to risks of toxicity for fish and beneficial bacteria, limiting its commercialization.

Entomopathogenic and mycoparasitic fungi have been identified as safe biological control agents for a broad range of pests. This study aimed to investigate the efficacy of entomopathogenic fungi, Lecanicillium attenuatum (LLA), Isaria fumosorosea (IFR), and mycoparasitic fungus Trichoderma virens (TVI) against Podosphaera xanthii. Also, we investigated the possible harmful effects of the three fungal biocontrol agents in aquaponics by inoculating them in aquaponics water and monitoring their survival and growth. The findings showed that the three biocontrol agents significantly suppressed the powdery mildew at 107 CFU/ml concentration.

Under greenhouse conditions (65-73% relative humidity (RH)), a significant disease reduction percentage of 85% was recorded in L. attenuatum-pretreated leaves. IFR-treated leaves had the least AUDPC (area under disease progress curve) of ~434.2 and disease severity of 32% under 65-73% RH. In addition, L. attenuatum spores were the most persistent on the leaves; the spores population increased to 9.54 × 103 CFUmm-2 from the initial 7.3 CFUmm-2 under 65-73%. In contrast, in hydroponics water, the LLA, IFR, and TVI spores significantly reduced by more than 99% after 96 hrs. Initial spore concentrations of LLA of 107 CFU/ml spores were reduced to 4 x 103 CFU after 96 hrs. Though the results from this study were intended for aquaponics systems, the relevance of the results to other cultivation systems are discussed.

Read the complete research at www.researchgate.net.

Folorunso, Ewumi Azeez & Bohata, Andrea & Kavkova, Miloslava & Gebauer, Radek & Mraz, Jan. (2022). Potential use of entomopathogenic and mycoparasitic fungi against powdery mildew in aquaponics. Frontiers in Marine Science. 9. 10.3389/fmars.2022.992715. 

Publication date: Wed 9 Nov 2022

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Home | Arts + Culture | Wild Things

Bold jumping spiders will attack larger prey, leaping four times the length of their body

By Jeanine Farley

Saturday, November 5, 2022

Bold jumping spiders are very hairy, with four pairs of eyes. (Photo: Claire O’Neill/Earthwise Aware)

What’s small and hairy and jumps? Perhaps a bold jumping spider, which is one of the most common jumping spiders in North America. These spiders are not dangerous. If you pick one up, for example, it probably will not bite you (but I make no guarantees). If it did bite you, its fangs would probably not penetrate your skin, and if they did pierce the skin, the venom is too weak to cause harm to humans.

The legs of adult bold jumping spiders sport bands of silver hairs, while juveniles have orange or yellow bands. (Photo: Joe MacIndewar/Earthwise Aware)

These spiders (Phidippus audax) are so named because they are fearless and quick to jump on and attack prey that is larger than they are. “Audax” is from the word audacity, meaning “bold” or “daring.” They prey on many insect pests, including mosquitoes. These little critters (one-quarter to three-quarters of an inch) are also able to jump four times their body length.

Probably the most prominent feature of jumping spiders is that they are hairy. Bold jumping spiders are mostly black with a white or reddish triangle and two small dots on their abdomens. Their fangs or mouthparts(chelicerae) are metallic green – a feature sometimes more noticeable on males.

Bold jumping spiders display metallic green fangs or mouthparts that are more pronounced in males. (Photo: Claire O’Neill/Earthwise Aware)

Bold jumping spiders hunt during the day. They sneak up on their prey and pounce, injecting venom that paralyzes their prey. We all know that spiders have eight legs; most spiders, including bold jumping spiders, also have eight eyes. This gives them the sharp vision they need to stalk their prey. In fact, jumping spiders – with eyes in a semicircle around the head, each pair of a different size, with the two in the middle being the largest – have the sharpest vision of all spiders. These two largest eyes give the spider good three-dimensional vision, while the other six eyes provide it with 360-degree views of the surroundings.

Bold jumping spiders are the state spider of New Hampshire, but this spider hunts on Prospect Hill in Somerville. (Photo: Claire O’Neill/Earthwise Aware)

Jumping spiders do not spin webs, but before they jump they attach a strand of silk to the surface they are on. If they jump and miss, they are still tethered to the tree or wall from which they jumped. They also use silk to make a cocoonlike resting place (in dried leaves, under rocks, in tree crevices) where they, eat their prey and protect their eggs.

Birds and dragonflies and small mammals prey on bold jumping spiders. If you have ever seen a bird digging an insect out from a tree fissure, you might have witnessed the demise of a bold jumping spider.

Juvenile bold jumping spiders have an orange-tinted triangle and two small dots on their abdomens. These spots become whiter in adults. (Photo: Joe MacIndewar/Earthwise Aware)

Similar to snakes, spiders shed their outer skin as they grow larger. Bold jumping spiders stop the process in the fall as adolescents and overwinter as sub-adults. In the spring, they finish growing to adulthood. They breed from spring to early summer; the female bold jumping spider produces an egg sac containing 30 to 170 eggs. (With six to eight egg sacs per season, that’s a lot of baby spiders.) She guards the egg sac until the baby spiders hatch; then the babies are on their own.

The spiders prefer flat vertical surfaces where they can see and easily pounce on their prey. Therefore, these spiders like broad-leaved plants such as milkweed, for example, or tree trunks, fenceposts and house siding. If you should happen to see a bold jumping spider inside your cellar or on your lawn furniture, let it be; it is shy and harmless, will most likely run or jump away if it detects you, and can help control insect pests.

Bold jumping spiders like this one in the Cambridge Highlands can detect vibrations from a great distance and jump four times its body length. (Photo: Claire O’Neill/Earthwise Aware)

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A bald eagle is spotted in Ball Square, Somerville, in mid-October. Its unusual left eye identifies it as KZ, the male of the nesting pair on the Mystic Lakes. (Photo: Jeanine Farley)

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Have you taken photos of our urban wild things? Send your images to Cambridge Day, and we may use them as part of a future feature. Include the photographer’s name and the general location where the photo was taken.


Jeanine Farley is an educational writer who has lived in the Boston area for more than 30 years. She enjoys taking photos of our urban wild things.


 

November 11, 2022

 

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‘Wonder weevils’ released in Yorkshire waterways in fight against invasive floating pennywort

Biopesticides and Biocontrols 

‘Wonder weevils’ released in Yorkshire waterways in fight against invasive floating pennywort

   Delhi Bureau  0 Comments CABI  3 min read

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16 November 2022, America: Specialist weevils from South America have been introduced to two sites in West Yorkshire to control an invasive non-native plant choking waterways.

The floating pennywort weevils have been introduced on the Aire and Calder Navigation and one of the tributaries of the River Holme, in a collaboration by CABI, Yorkshire Water, Leeds City Council, River Holme Connections and a private landowner.

As reported by PA Media and syndicated to over 114 UK news outlets including the London Evening Standard, Belfast Telegraph, Glasgow Times and Oxford Mail, the bugs, which have evolved to only feed and develop on floating pennywort (Hydrocotyle ranunculoides), will target the plant where it is clogging up the waterways.

Floating pennywort is native to Central and South America, and was brought to the UK in the 1980s as an ornamental pond plant, but escaped into natural habitats where it can grow up to 20cm a day.

Back in May, CABI revealed how its research has been the forefront of a world-first after the weevil – a more than 10 years under study – started to be released in England to sustainably fight the floating pennywort.

The release was timed to coincide with Invasive Species Week 2022. Invasive Species Week is an annual national event to raise awareness of the impacts of invasive non-native species, the simple things that everyone can do to prevent their spread, and some of the fantastic work taking place across the UK, Ireland, Jersey, Guernsey and Isle of Man to protect the environment and reduce their impacts.

Since 2011, CABI, with Defra funding, has been investigating the potential use of a biocontrol agent for floating pennywort which has the ability to grow up to 20 centimetres each day. It forms dense rafts over rivers and harms native plant, fish and invertebrate species, through competition and cutting oxygen levels in water.

Floating pennywort – an ornamental pond plant originating from North America – also impedes navigation routes, disrupts recreational activities like fishing and canoeing and exacerbates flood risk.

Dr Steph Bradbeer, invasive species and biosecurity adviser at Yorkshire Water, said: “Invasive non-native species pose a very real risk to Yorkshire’s environment and wildlife.

“They can also impact on our ability to treat and distribute water to homes and return wastewater safely to the environment.

“Floating pennywort, if unchecked, can cause significant problems in slow-flowing watercourses and impact drainage systems.

“We hope the release of these specialist weevils will provide a way of tackling it without the need for mechanical or chemical intervention.”

Djami Djeddour, senior project scientist at CABI, said: “These weevil releases are the culmination of over a decade of collaboration with South American scientists and comprehensive safety and efficacy testing in our quarantine facilities, so it is thrilling to finally get them out into the wild.”

The weevils will be closely monitored, with their impact on the spread of floating pennywort carefully monitored.

It is hoped they will help improve local wildlife and water quality, reduce the plant’s impact on flood defences and control the spread of floating pennywort in rivers.

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DLNR NEWS RELEASE – NEW VIDEO HIGHLIGHTS HOW BIOCONTROL SAVED NATIVE WILIWILI TREES

Posted on Nov 16, 2022 in Latest Department NewsNewsroom

(HONOLULU) – A new animated video highlights the success story of how biocontrol, a process where a carefully selected living organism is used to control an invasive species, helped to save the native Wiliwili tree. The video, produced by the DLNR Division of Forestry and Wildlife (DOFAW) in collaboration with the Coordinating Group on Alien Pest Species, also shows how biocontrol can continue to be an important tool in managing invasive species in Hawaiʻi.

In 2005, a new pest, the erythrina gall wasp, made its way to Hawaiʻi and rapidly spread across the state, killing or severely damaging nearly all wild Wiliwili populations. “The sudden arrival of the erythrina gall wasp caught us all by surprise,” says Chipper Wichman, President of the National Tropical Botanical Garden. “Wiliwili is a keystone species in our dry forests, and nearly every part of this special tree is used by cultural practitioners. The impact of losing this species would have been profound.”

However in 2008, after extensive exploration in Africa for predators of the gall wasp and testing to make sure those predators didn’t impact other species, scientists were able to safely release a biocontrol agent: an even smaller parasitic wasp that preys on the gall wasp. The biocontrol agent successfully reduced the pest wasp numbers to levels that did not kill Wiliwili trees, saving them from the edge of extinction.

“Invasive species cost the state millions by reducing watershed benefits, degrading agricultural lands, threatening human infrastructure, and are one of the main drivers of the loss of biodiversity and native ecosystems in our state,” DOFAW Protection Forester Rob Hauff said. “Biocontrol has proven to be a safe, cost-effective, and essential tool. The success of the Wiliwili gall wasp biocontrol is one example of what we can expect if we continue to support this type of work.”

Prior to releasing a biocontrol agent, researchers perform years of exploration and analysis to ensure it won’t impact any species other than the target invasive species. Proposed biocontrols are also subject to careful review by specialists and regulatory officials, as well as the public. Since the focus on safety was implemented in Hawaiʻi in the 1970s, the biocontrol program has had a stellar record, with no non-target damages from any biocontrol released in the last 50 years.

Given the ongoing impacts of many invasive species currently in Hawaiʻi, new, updated facilities are needed to expand the capacity for biocontrol research. A coalition of state and federal agencies, including DLNR, the Hawaiʻi Department of Agriculture (HDOA), the University of Hawaiʻi, and the United States Forest Service and Agricultural Research Service, are currently discussing options for new facilities that can serve Hawaiʻi and other Pacific island neighbors, who often deal with similar invasive species.

While discussions on new facilities are ongoing, there are still new biocontrol agents that may be ready for release in the near future. Two insects, including a caterpillar targeting the weed miconia (Miconia calvescens), and a beetle targeting the weed cane tibouchina (Tibouchina herbacea), may be ready for release in Hawaiʻi within the year.

# # #

RESOURCES

(All images/video courtesy: DLNR)

Animated Video – Wiliwili Trees in Hawaiʻi: A Biocontrol Success Story: https://vimeo.com/764310295/75668bbed2

Photographs – Wiliwili Trees: https://www.dropbox.com/sh/26iq4inb956i1zc/AACHgND3m0E2RBeeUS0YsNRJa?dl=0

Biocontrol Hawaiʻi webpage: www.biocontrolhawaii.org

Media Contact:

Madison Rice

Communications Specialist

Hawai’i Dept. of Land and Natural Resources

Dlnr.comms@hawaii.gov

808-587-0396

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Weevil may save Great Britain up to £16.8m a year in management of invasive aquatic fern

by CABI

Weevil may save Great Britain up to £16.8m a year in management of invasive aquatic fern
The invasive aquatic fern Azolla filiculoides. Credit: CABI

A new CABI-led study suggests that a tiny weevil (Stenopelmus rufinasus) has huge benefits in saving Great Britain up to £16.8m in annual management costs of the invasive aquatic fern Azolla filiculoides.

The research, published in the journal CABI Agriculture and Bioscience, estimates that without any biocontrol the expected yearly costs of managing A. filiculoides would range from £8.4m to £16.9m.

The scientists say that the impacts of naturalized S. rufinasus populations on A. filiculoides alone could be expected to reduce management costs to £800,000 to £1.6m a year.

However, they estimate A. filiculoides management costs to be lower still due to additional augmentative releases of the weevil that take place each summer, resulting in annual management costs of £31,500 to £45,800.

Azolla filiculoides, a type of floating water fern, was introduced to Great Britain at the end of the 19th century for ornamental use in ponds and aquaria. But its introduction into the wild has meant it has spread rapidly throughout England and Wales and to a lesser degree, Scotland.

The invasive aquatic fern outcompetes native species by forming a dense covering on the surface of the water. It blocks out light and can also deoxygenate water. A. filiculoides can also block canals, drains and overflows and may lead to an increased risk of flooding. It can affect irrigation systems—both by blocking their water supply and by reducing water quality.

It has been banned from sale in England and Wales since April 2014.

Its specialist natural enemy, S. rufinasus, was first recorded in 1921. It is suspected to have been introduced from America as a stowaway on A. filiculoides. Stenopelmus rufinasus is also reported to be present in numerous additional European countries where A. filiculoides is present.

The study sought to estimate the management cost savings resulting from the presence of S. rufinasus as a biocontrol agent in Great Britain. This includes the value of additional augmentative releases of the weevil made since the mid-2000s, compared with the expected costs of control in the absence of S. rufinasus.

Corin Pratt, lead author and Invasive Species Management Researcher at CABI, said, “The unintentional introduction of the weevil S. rufinasus to Great Britain is estimated to have resulted in millions of pounds of savings annually in management costs for A. filiculoides.

“Additional augmentative releases of the weevil provide further net cost savings, tackling A. filiculoides outbreaks and bolstering naturalized populations.

“The use of herbicides in the aquatic environment is likely greatly reduced due to A. filiculoides biocontrol. Although somewhat climate-limited at present in Great Britain, climate change may result in even more effective biocontrol of A. filiculoides by S. rufinasus.

“This has been observed in warmer regions such as South Africa, where the plant is no longer considered a threat since the introduction of S. rufinasus.”

The scientists conclude by arguing that in the absence of the specialist weevil S. rufinasus, A. filiculoides could be expected to be the dominant aquatic macrophyte in Great Britain. This would require extensive, costly management and likely widespread use of herbicides in the aquatic environment.

They state that the estimated benefit to cost ratio of augmentative S. rufinasus releases to be of 43.7:1 to 88.4:1.

More information: Corin F. Pratt et al, A century of Azolla filiculoides biocontrol: the economic value of Stenopelmus rufinasus to Great Britain, CABI Agriculture and Bioscience (2022). DOI: 10.1186/s43170-022-00136-0

Provided by CABI

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PestNet

Grahame Jackson posted a new submission ‘Risk analysis and weed biological control.’

Submission

Risk analysis and weed biological control.

Authors: W. M. LonsdaleD. T. BrieseJ. M. CullenAUTHORS INFO & AFFILIATIONS

Publication: Evaluating indirect ecological effects of biological control. Key papers from the symposium ‘Indirect ecological effects in biological control’, Montpellier, France, 17-20 October 1999

https://doi.org/10.1079/9780851994536.0185


Abstract

Weed biological control and risk analysis are very powerful tools for land management and decision-making respectively. We explore the application of risk analysis to weed biological control. Recent criticisms of weed biological control have mainly centred on non-target impacts, attacks by the biological control agent on species other than the weed. In ecology, these are direct effects because they involve physical interactions between the species concerned. Indirect effects are those in which the species do not physically interact. In biological control terms, indirect effects include, on the positive side, the increase in pasture production or biodiversity resulting from successful biological control. On the negative side, they include the decline of a native species that had used the weed as habitat. The aim of weed biological control is then to maximize the ratio of desirable indirect effects to undesirable direct and indirect effects. Using a risk analysis approach, we show that the problems of weed biological control are less in the domain of science and more in that of communication and consultation. A well-conceived biological control project would aim for wide consultation to agree on the target weed with the community, so that negative effects are viewed as trivial against the positive ones. It would also use highly specific agents to reduce the risk of undesirable direct effects to a minimum. Lastly, biocontrollers themselves would merely be advisers on the decision to release.


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With Xsect Xtra, Inveragro eliminates pepper pests

Inveragro, located in the valley of San Felipe, Guanajuato, and known for its tradition of producing and drying chili peppers, was having problems with pest control and humidity levels inside the greenhouse. With Xsect Xtra, they were able to reduce the entry of thrips by 50% while increasing their humidity by 15%, resulting in an ideal climate that promotes pepper growth.

Inveragro is a 10-hectare pepper greenhouse that started operations three years ago in the valley of San Felipe, Guanajuato, an area with different challenges for pepper growers due to its semi-arid climate and the presence of insects and pests such as whitefly, thrips, and weevils.

Germán Sandoval Barba, grower at Inveragro, was looking for a climate solution that would help him face these challenges. A year ago, he decided to try Xsect Xtra.

Ideal humid climate = healthier peppers
The pepper is a tropical crop that likes high humidity levels. Ideally the humidity inside a pepper greenhouse should be between 60% and 80%.

During the summer months, humidity inside Inveragro was between 45% and 50%, and it was necessary to keep the windows closed as a way to conserve humidity inside the greenhouse.

“Before installing Svensson’s insect control nets, I was worried that the temperature would rise too much and that it would affect the humidity. Once we tested the nets, the truth is that it was a very positive surprise the results that we had in terms of temperature and humidity”, says Germán Sandoval

Unlike last year when the windows were practically closed, now with Xsect Xtra, the windows are open between 20% and 30%, having a maximum temperature between 32 and 33 degrees. In addition, with Xsect Xtra, the humidity inside the greenhouse increased between 10% and 15%, compared to last year, achieving an ideal humidity between 60% and 75%, which benefits the growth of peppers.

“I thought that I was going to experience disadvantages with this insect control net because, for me, it was more important to sacrifice climate in order to reduce the entry of pests and insects. But to my surprise, I now have a better climate and fewer insects inside the greenhouse,” said Germán Sandoval.

Greenhouses with 50% fewer thrips
One of the biggest challenges for Germán is the entry of pests, and one way to control this problem is through hermeticity. Inveragro has four full-time employees dedicated exclusively to supervising any failure in the hermeticity of the greenhouses. “When I started looking for options to improve our hermeticity, I discovered the Svensson insect control nets, which would help us to improve our conditions,” says Germán Sandoval.

Before installing Xsect Xtra, during the fifth week of the production cycle, thrips were already seen inside the greenhouse, and it was necessary to apply pesticides and/or agrochemicals prior to the release of the biological control. “Now I can release the biological control we use Orius to control thrips, without pesticides and/or agrochemicals applications that could damage the biological control program,” says Germán, “since the installation of Xsect Xtra, 50% fewer thrips have entered the greenhouse”.

Powdery mildew was another climate problem at Inveragro, and it was necessary to apply agrochemicals at least once a week. During the first year with Svensson’s insect control net, Germán continued with the same program, but no powdery mildew was found inside the greenhouse.

“I’ve already modified my program for this year. I’m only going to apply preventive products every 15 days, which reduces by 50% the cost of powdery mildew throughout the year because now I have better climate conditions in terms of humidity, which is more controllable and promotes pepper growth”.

Germán has also noticed improvements in the beneficial program used to control thrips. He used to have 4 Orius per square meter, and this year he only has three orius per square meter, which means savings in this year’s beneficials budget.

“What Xsect Xtra has given me is improved humidity, fewer pests, and reduced phytosanitary diseases.”
 
Finally, Germán shared the following advice for all pepper growers: “I would tell growers who are afraid to try these nets not to be afraid. In the beginning, I hesitated, but it is something that will help them. What it can generate in the climate is minimal and what it can help them in the phytosanitary issue is very broad. The net pays for itself”.

For more information:
Ludvig Svensson

info@ludvigsvensson.com www.ludvigsvensson.com    

Publication date: Mon 14 Nov 2022

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Managing a Major Fungus in Greenhouse Cucumbers With Biologicals

Zamir K. PunjaBy Zamir K. Punja|November 9, 2022

  • Powdery mildew can become a problem for greenhouse cucumbers if not managed in a timely manner. The disease is easy to recognize by the white colonies that develop on the surface of cucumber leaves. These are visible evidence of growth of the mildew pathogen, which develops mycelium and spores on the leaf surface, while drawing nutrients from within the leaf using feeding structures called haustoria that are immersed within the epidermal cells. The damage caused by this disease is due to the removal of these photosynthates from the host plant. In addition, growth of the pathogen over the plant surface reduces incoming irradiation and impacts photosynthesis. Severely infected leaves will turn brown and die. The combined yield loss from infection of susceptible cucumber varieties by powdery mildew can be as high as 15% to 20%.START SLIDESHOW
  • START SLIDESHOW
  • 1 of 4Figure AFigure AThis graph shows how three applications of Bacillus used preventatively can reduce powdery mildew development.  Graphic: Zamir PunjaNEXT SLIDE
  • 2 of 4Figure BFigure BThe leaf treated with Bacillus is shown on the left and the untreated leaf is on the right. Photo: Zamir PunjaNEXT SLIDE
  • 3 of 4Figure CFigure CThis chart shows how three applications of Bacillus can eradicate disease after it has become established. Graphic: Zamir PunjaNEXT SLIDE
  • 4 of 4Figure DFigure D
  • The treated leaf is on the left and the untreated leaf is on the right. Photo: Zamir PunjaNEXT SLIDE

Disease Develops in Favorable Conditions

Disease development is favored by dense canopy development, low light conditions, and warm temperatures (70ºF to 80ºF). Higher relative humidity (>70%) favors infection by spores, while drier conditions favor colony development and production and release of spores, which result in spread of the pathogen. Spores can remain viable for up to seven days and can spread to neighboring plants. In a matter of three to seven days, new infections result in colonies appearing on leaves.

Growing resistant varieties to powdery mildew is one option for disease management; however, these are not always available. Fungicide use where permitted can reduce disease but can be costly, cause some foliar damage under warm temperatures, as well as potentially increase the development of fungicide-resistant strains of the pathogen over time.

Biological Controls Reduce Powdery Mildew

Another approach to reduce development of powdery mildew is the application of biologicals that contain active microbes. These act on the pathogen by reducing mycelial growth, spore production, or spore germination. They must be applied early before the disease gets established (when very small mildew colonies are visible) and require weekly applications. Biologicals are also subject to rapid decline in numbers if the temperatures are very warm (>80ºF) and if the humidity is low (50%) and UV irradiation levels are high (during full sunlight, for example).

To demonstrate the use of microbial biological agents, we evaluated several products that contain microbes to demonstrate their effectiveness.

The results using Bacillus spp. are described here. These bacteria are widely used to manage diseases on a range of crops worldwide and are registered for use on greenhouse vegetable crops. Many Bacillus species produce a broad range of antibiotic compounds that reduce growth of fungi, such as powdery mildew. They also produce enzymes that degrade the mycelium of fungi, reducing growth. Bacillus species produce resistant endospores that help them survive through dry conditions and avoid the effects of UV. Therefore, they are quite suited for use on agricultural crops.

Treatment Options

There are two options for application of microbials containing Bacillus — just when disease is initiated as preventative treatments, and after it has become established as eradicative treatments. We evaluated both approaches. Using a concentration of 1 liter (L) of Bacillus subtilis strain QST 713 (formulated as Rhapsody) in 100L of water, applications were made weekly as preventative or eradicative treatments. Disease was assessed as the number of mildew colonies on leaves and the percentage of leaf area infected.

The difference in the number of mildew colonies per leaf can be seen in Figures A and B, where three weekly applications reduced colony numbers from 48 to 10.

If mildew was first allowed to develop to cover about 25% of the leaf surface and then Bacillus was applied, three weekly applications reduced the leaf area infected to 15% compared to the untreated control that reached 95% (Figures C and D).

Here are a few treatment tips:

  • Growers are encouraged to spray Bacillus during the morning hours when temperatures are cooler.
  • Ensure good foliar coverage and repeat applications every seven days.
  • Mildew control can be obtained before mildew appears as a protective measure.
  • Mildew control can also be obtained when disease has started but is less than 25% of leaf coverage.
  • Re-entry time after application is four hours.

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The Ecosystem: innovation in biocontrol held back by lack of fast-track registration

08 Nov 2022 | News

New rules for approving microorganism-based plant protection products coming into effect in November don’t go far enough to lift the regulatory drag on innovation. This will hold back efforts to phase out chemical pesticides

By Ian Mundell

Combine harvester in a field

Registering a biocontrol product can take several years longer in the EU compared to the US. Photo: Andriy Medvediuk / Bigstock

New rules on the data required to register microorganism-based plant protection products coming into effect this month should benefit both start-ups and established companies, by speeding up registration and time to market. But the change falls short of the fast-track procedure the industry was hoping for.

The problem biocontrol companies face is that any plant protection products destined for the European market must go through an approvals process that was designed with chemical pesticides in mind.

This can be an awkward fit for products with active ingredients such as bacteria, fungi, viruses and protozoa. The new data requirements are intended to tackle this anomaly, tailoring registration procedures for these microorganisms to their biology and ecology.

“The data requirements are a step in the right direction, a bit of biology logic that gets into a legislative system mainly inspired by chemicals, but it is not enough,” Herman Van Mellaert, president of the International Biocontrol Manufacturers Association (IBMA), told the European Parliament in mid-October. “We need further initiatives in terms of Commission guidelines and measures to make [the current regulation covering plant protection products] and these new data requirements work, so that we can get through the system on a fast track.”

A similar sentiment can be heard from start-ups in the field. “In the US, you can register a biocontrol product within 2-3 years, while the same process in Europe takes seven or more years. So, making that quicker, more efficient and simpler will help a lot,” Anna Ogar, co-founder and chief executive of Microbe Plus, told Science Business. “For now, the changes that are proposed for a faster regulatory approval seem like a good idea, but we need to know what the final shape of the law will be.”

The irony is that Europe’s lawmakers and the biocontrol industry should be on the same page. The Commission’s desire to reduce the use of chemical pesticides is written into the European Green Deal, the Farm to Fork Strategy, and its draft regulation on the sustainable use of pesticides, which proposes a 50% reduction target for pesticide use by 2030. Alternatives need to be available on the European market sooner rather than later.

The lengthy process is a particular problem for privately funded start-ups. “Investors do not want to hear that regulatory approval will take several years, even those who may be used to the pharmaceutical sector,” Ogar said. “Shortening that period from 5-7 years to three years will make a space for patient investors. They can be confident that the product will either be positively assessed, or they can terminate it, but either way they will have an answer much earlier in the process.”

Microbe Plus, based in Lublin, Poland, was founded in 2020 and currently has a staff of seven. It is developing a blend of different strains of bacteria that protect against plant pathogens and also act as a stimulant. “By making a blend we try to cover multiple crops, at various stages, and the broadest pathogen spectrum possible,” Ogar said. “So far, we’ve validated our product on more than 50 different pathogens in 20 different crops.”

These strains have been isolated and genetically characterised in-house. “We started with around 2,000 strains and have narrowed it down to 10 that we are working with, and which appear to be the most effective, efficient and, importantly for regulatory approval, have a good safety profile,” Ogar said. “Nowadays, efficiency is less important than safety protocols for newly registered products.”

Over the past few years, Microbe Plus has put its blend through laboratory tests, greenhouse tests, and field trials. “We’ve proved that we can improve yield by 5% to 15%, which is a good result for open field trials.”

So far, this work has been self-funded and supported with grants, the next step is to secure a first funding round. But the cost and complexity of the product registration process that lies ahead means that, like many start-ups in the sector, Microbe Plus cannot afford to work alone.

“For a young company that doesn’t have a track record, it is impossible to secure money for this process, so partnerships, joint ventures or licensing are the only way,” Ogar said. The company is in the process of partnering with a big crop protection producer, which is validating the technology in Europe and the US.

If this feels a little like giving up early on the entrepreneurial dream, there are compensations. One is that it presents an opportunity for the product to have a global impact, far beyond what a start-up could hope to achieve on its own. Another is that industry partnerships are not as one-sided as they once were.

“Nowadays the big corporations are much more open to discussing the possibilities for long-term collaboration with start-ups,” Ogar said. “They realise that buying the intellectual property is one thing, but further development proceeds much faster and more efficiently when the people who had the idea are still on board.”

Regulation holds back innovation

Even established biocontrol companies are hampered by Europe’s registration process, and this is being exacerbated by a parallel demand that they re-register existing products to fit with new EU transparency rules.

According to José Carvalho, regional representative for Europe and the Middle East at the multinational Certis Biologicals, this has resulted in a shift in investment towards keeping current biocontrol technologies on the market, and registering new products that are similar to existing technologies.

“This reduces uncertainty for our boards and our investors, who need to advance millions of euros to bring these products to the market,” he told the European Parliament. “But there will be no innovation if our resources are spent looking at existing technologies.”

The industry sees the need to act quickly, and for the moment has stopped arguing for an entirely new regulation, inspired by biological principles, to oversee its products. “We don’t have the time to wait for a new regulation,” Van Mellaert said. “We have to work with what we have, but there is a lot of potential to work with [the current regulation] in such a way that we create that fast track and enable nature-based solutions to have access to the market.”

One development the IBMA would like to see is provisional authorisation, allowing industry and farmers to get experience using biocontrol products under real world conditions. According to Carvalho, this would be possible under the existing regulation.

The industry also wants to see the tailored data requirements for natural products used as active ingredients, such as substances used to modify the behaviour of insect pests.

Alongside regulatory reform, farmers need help making the transition from synthetic to bio-based products. “It requires from them a better understanding of how biological products work. For example, you have to apply them at a different rate, at different times, and it involves a learning process,” Ogar said.

There is still a level of resistance. “Farmers are afraid that when the biologicals come, they will be less effective, much more expensive, and they will have to apply them multiple times. So, their immediate reaction is to stick to chemicals as long as they can.” This is a challenge that the industry, regulators and governments will have to address together, she adds.

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Fruit and vegetable crops in the Willamette Valley have been affected

USDA ARSWFP-ARS-BMSB.jpg

One promising biological approach is the samurai wasp (Trissolcus japonicus),

The brown marmorated stink bug has increased this year.

Fruit and vegetable crops in the Willamette Valley have been affected.

Kym Pokorny | Nov 11, 2022

Jan 18, 2023 to Jan 20, 2023

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The amount of invasive brown marmorated stink bugs in 2022 tops anything seen in Oregon for at least five years and poses a serious threat to Oregon crops and garden plants, according to Oregon State University Extension Service’s orchard crop specialist.

Nik Wiman, an associate professor in the College of Agricultural Sciences, said fruit and vegetable crops in the Willamette Valley have been affected.

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“It’s unusual for brown marmorated stink bugs to feed on fruit and vegetable crops,” he said. “There has been a lot of damaging populations of BMSB in hazelnuts orchards. Growers use preventative measures so we’re surprised we’ve seen so many.”

It’s unclear why the population exploded this year, Wiman said. Like other insects, the population of the shield-shaped brown marmorated stink bug (BMSB) varies from year to year depending on climatic factors. The extremely wet spring most likely contributed to it, but the increase could also be attributed to a natural cycle.

Native to Asia, BMSB was introduced on the U.S. East Coast in the late 1990s – probably by ship – and has spread to almost every state in the country, including Oregon in 2004. The insect feeds on at least 170 plants, particularly vegetables, pears, apples and hazelnuts, but also ornamentals. Its name describes the odor they emit when they’re crushed.

Oregon’s hazelnut industry, valued at $132 million in 2020, is one of the state’s crops hardest hit by the invasive bug, according to the Oregon Department of Agriculture. The state’s problem echoes the situation in Turkey – the world’s leader in hazelnut production – as well as Italy and the country of Georgia, said Wiman, who researches alternative practices for controlling BMSB, including biological control, habitat manipulation, trap crops and barriers.

Samurai wasp

One promising biological approach is the samurai wasp (Trissolcus japonicus), an insect native to areas of Asia where it keeps the indigenous BMSB population under control. Scientists have discovered the wasp in the United States and Oregon, where it was initially distributed across the state by Wiman and a team of scientists at OSU and elsewhere.  The Oregon Department of Agriculture is now leading the effort.

The parasitic wasp hunts for the egg masses of the stink bug and lays an egg inside each egg in the mass. The wasp develops inside the egg, effectively killing the stink bug, and then chews its way out. OSU Extension has a short publication on the wasp and its effect on the stink bug.

In addition to agricultural crops, the stink bug shows up in homes in autumn when they are looking for a warm, dry place for winter.

“We’ve done analysis of reports we get from people,” Wiman said. “We’ve looked at timing and by far and away we get the most BMSB reports in the fall. Adults are at peak and are trying to get into houses. Warm fall weather gives more opportunity to get into buildings. They can be very annoying when they are coming into homes, and they may fly around inside your house all winter. Then they come out in spring.”

Wiman advises homeowners to seal all cracks where the stink bug can enter and vacuum up inside infestations. On outdoor buildings, washing them off with a strong shot of water will keep some at bay. If they come back, spray them again.

Farmers and homeowners can serve a key role in samurai wasp research by collecting possible brown marmorated stink bug egg masses and reporting them.

[Kym Pokorny is a communication specialist at OSU.]

Source: Oregon State University

TAGS: CROPS

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