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May 3, 2017 by Entomology Today Leave a Comment

beauveria-bassiana-effect-on-insects

Beauveria bassiana is a fungal endophyte that thrives in a host plant without harming it, but it is parasitic to insects that consume the plant, as shown in this example of the resulting effects on pecan weevil larvae. A recent study in Argentina finds B. bassiana to also negatively affect Dichroplus maculipennis, a common grasshopper pest of crops in the region. (Photo credit: Louis Tedders, USDA Agricultural Research Service, Bugwood.org)

By Andrew Porterfield

Grasshopper species, including Dichroplus maculipennis, are common insect pests. They have been known to cause widespread damage to crops such as corn, soybeans, and wheat, by devouring the leaves and stems of targeted plants.

The only means of controlling D. maculipennis so far is with chemical pesticides, which can have environmental consequences. Researchers have therefore been looking for other, biological solutions to reduce the impacts of grasshoppers.

In Argentina, where several outbreaks of D. maculipennis wreaked losses on ranches and farms between 2008 and 2011, a research team led by Sebastian Pelizza of CEPAVE (Central de Estudios Parasitologicos y de Vectores, or Center for Parasitological and Vector Studies, part of the National University of La Plate), looked at the possibility of using the soil fungus Beauveria bassiana to combat D. maculipennis swarms and outbreaks. His study was published on line in April in the open-access Journal of Insect Science.

  1. bassiana is an endophyte: It takes up residence in a host plant and thrives without harming the plant. It also is known to be parasitic to insects. It’s often used for biological control of insect pests of agricultural plants, but Pelizza’s study is the first to look at B. bassiana‘s ability to resist D. maculipennis in corn. D. maculipennis is one of 18 species of grasshopper pests found in Argentina but is considered one of the most significant pests, especially in the grassland Pampas region of the country. The region is an important agricultural center for the country, and much of the native grasslands has been converted to grow soybean, corn, sunflower, and wheat. Corn is a major crop for Argentina—about 36 metric tons a year was produced in 2015, and that amount is increasing, thanks to a number of regulatory changes including removal of a corn export tax.

Pelizza’s team inoculated 300 corn plants with B. bassiana fungal strains to test grasshopper consumption of corn plants, 350 corn plants to test grasshopper reproductive ability, and 50 plants to test whether grasshoppers preferred corn with the fungal endophyte. An equal number of control plants did not have the B. bassiana inoculate.

The results showed significant impact of B. bassiana on grasshoppers. Daily consumption of control corn (without the inoculate) was twice that of corn plants with B. bassiana. Grasshopper fecundity was also impacted: females laid only 17.7 eggs during a 15-day feeding period while feeding on inoculated plants, compared to females that laid 27.2 eggs during the same time while eating control plants. Fewer embryonated eggs were seen in females feeding on inoculated plants, too. Finally, many more grasshoppers preferred to feed on control (untreated) plants (more than 300 mg of plant), compared to just 25 mg of treated plants.

The mechanism by which B. bassiana thwarts consumption and preferences of D. maculipennis is not known. The researchers noted also that about 70 percent of dead grasshoppers developed growth of B. bassiana on their bodies. This could mean that the fungus was in the bodies of these insects while they were alive and was affecting reproductive activity and possibly feeding behavior. Further studies are necessary to study this possible mechanism, as well as whether B. bassiana endophytes could produce substances toxic to humans.

“The effects of B. bassiana on consumption, fecundity, and food preferences of D. maculipennis have never been studied when used as an endophyte microorganism in corn,” Pelizza and his colleagues write. “This appears to be an interesting tool that could be considered to control this species of grasshopper pest.”

Read More

Beauveria bassiana (Ascomycota: Hypocreales) Introduced as an Endophyte in Corn Plants and Its Effects on Consumption, Reproductive Capacity, and Food Preference of Dichroplus maculipennis (Orthoptera: Acrididae: Melanoplinae)

From Pestnet

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2017/065 First reports of a new bacterial leaf blight of rice caused by Pantoea anana and Pantoea stewartii in Benin and Togo

In Benin, surveys were carried out from 2011 to 2015 in rice fields to assess the importance of bacterial leaf blight caused by Xanthomonas oryzae pv. oryzae (EPPO A1 List). Symptomatic leaf samples were collected and tested. As all isolates gave negative results in a multiplex PCR test for X. oryzae, further studies were conducted and revealed the presence of bacteria belonging to the genus Pantoea. Molecular and pathogenicity tests (to fulfill Koch’s postulates) confirmed that the bacteria which had been isolated from rice leaves were P. ananatis and P. stewartii (EPPO A2 List). It is noted that symptoms were  observed in all surveyed localities (14 sites) with a disease incidence varying from 30 to 100%. In Togo, surveys were also carried out in 2013 and 2014 in the main rice-growing regions (Kovié and Kpalimé) to evaluate the prevalence of plant-pathogenic bacteria. Rice leaves showing characteristic symptoms of bacterial leaf blight were collected and tested. Similarly, the bacteria which were isolated from rice leaves and grains were shown to be P. ananatis and P. stewartii. According to the authors, this is the first time that P. ananatis and P. stewartii species are found causing a leaf blight disease on rice crops in Benin and Togo. According to the EPPO Secretariat this is also the first time that P. stewartii is reported from Africa.

Source: Kini K, Agnimonhan R, Afolabi O, Milan B, Soglonou B, Gbogbo V, Koebnik R, Silué D (2017) First report of a new bacterial leaf blight of rice caused by Pantoea ananatis and Pantoea stewartii in Benin. Plant Disease 101(1), p 242. Kini K, Agnimonhan R, Afolabi O, Soglonou B, Silué D, Koebnik R (2017) First report of a new bacterial leaf blight of rice caused by Pantoea ananatis and Pantoea stewartii in Togo. Plant Disease 101(1), 241-242.

From Pestnet

USDA releases proposals to fight citrus greening & diamondback moths

In the past two weeks, USDA’s Animal and Plant Health Inspection Service (APHIS) has released documents on proposals to release two genetically modified (GM) organisms: diamondback moths and a virus designed to control the citrus greening disease attacking the citrus industry.

DB moth

Diamondback moths are a global pest of cruciferous crops such as broccoli, Brussel sprouts and cabbage. On April 18, the USDA released a draft environmental assessment of a proposed experiment by a Cornell entomologist with GM diamondback moths.

The scientist, Anthony Shelton, plans to release tens of thousands of GM moths into a 10-acre vegetable field to test their potential as an “insecticide-free” control option for diamondback moths. The GM moths have been engineered to repress female survival, known as a “female autocidal trait.”

You can read the full assessment which concludes it will have no harmful effects here.

Citrus Greening
A Florida nursery, Southern Gardens Citrus Nursery, is proposing the release of a GM virus, Citrus tristeza virus, which has been engineered to express bacteria-fighting proteins found in spinach. The GM virus, which has been undergoing controlled field tests since 2010, would be grafted — not sprayed — onto citrus trees in Florida. USDA has announced its intent to launch an environmental impact statement on Southern Garden’s proposal.

source: dtnpf.com

Publication date: 4/25/2017

Diamondback moths are a global pest of cruciferous crops such as broccoli, Brussel sprouts and cabbage. On April 18, the USDA released a draft environmental assessment of a proposed experiment by a Cornell entomologist with GM diamondback moths.

The scientist, Anthony Shelton, plans to release tens of thousands of GM moths into a 10-acre vegetable field to test their potential as an “insecticide-free” control option for diamondback moths. The GM moths have been engineered to repress female survival, known as a “female autocidal trait.”

You can read the full assessment which concludes it will have no harmful effects here.

Citrus Greening
A Florida nursery, Southern Gardens Citrus Nursery, is proposing the release of a GM virus, Citrus tristeza virus, which has been engineered to express bacteria-fighting proteins found in spinach. The GM virus, which has been undergoing controlled field tests since 2010, would be grafted — not sprayed — onto citrus trees in Florida. USDA has announced its intent to launch an environmental impact statement on Southern Garden’s proposal.

source: dtnpf.com

Publication date: 4/25/2017

From Pestnet

reliefweb
http://reliefweb.int/report/kenya/fall-armyworm-spreads-east-africa

Report

from Food and Agriculture Organization of the United Nations

Published on 25 Apr 2017 — View Original

25/04/2017

As millions of east African farmers seek to recover from a devastating drought, they face a new threat – the fall armyworm. The pest has been recently detected in Kenya and is suspected to have entered the country from Uganda. It is also known to be present in Burundi, Ethiopia and Rwanda.

The fall armyworm was first reported in western Kenya by farmers in March 2017, and immediately confirmed by the Kenya Plant Health Inspectorate Service and Kenya Agricultural and Livestock Research Organisation. The initial counties infested were Busia, TransNzoia, Bungoma, Uasin Gishu and Nandi.

However, the pest has rapidly spread to key maize- and wheat-producing counties, including Kericho, Bomet and Narok in South Rift, as well as Nakuru and Baringo in Central Rift. Further, there are unconfirmed reports of presence of the pest in eastern and coastal areas. The major crop currently being ravaged by the pest is maize, which is at various stages of growth, ranging from germination to shoulder-high (nearing tasselling).

In Kenya, the Government has sought to respond quickly and effectively to prevent an outbreak from dampening prospects for the recently started main cereal-cropping season. With extension service providers and farmers not having much or any knowledge or skills on how to control and manage the fall armyworm, the Government has formed a platform to coordinate development of intervention strategies. However, as yet there are no funds available for implementation. Early this year, the Ministry of Agriculture and Natural Resources of Ethiopia received a report from Mizan Plant Health Clinic, which had intercepted the fall armyworm in five woredas (districs) of three zones – Bench-Maji, Kaffa and Sheka – located in southwestern Ethiopia, where early maize planting begins during January, February and March.

The Horn of Africa is already facing a regional humanitarian crisis, triggered by drought and leading to skyrocketing food insecurity, particularly among livestock-owning communities, with lives and livelihoods devastated across the region. Today, almost 18 million people in the Horn of Africa are severely food insecure as consecutive seasons of poor rainfall have led to crop failures, widespread pasture and water shortages, reduced opportunities for rural employment, increasing livestock deaths, rising food prices and rapidly diminishing access to food for poor households.

Drought has hit hardest in rural areas, where food security, nutrition and income generation is largely dependent on local agricultural and livestock production. In Somalia, Kenya, Ethiopia, Djibouti, South Sudan and Uganda, drought has scorched crops and rangelands, dried water sources and led to increasing rates of starvation, disease and death among livestock. Families are employing extreme coping strategies to survive, including skipping meals, selling productive assets and the migration or displacement of entire households.

The ongoing planting season represents one of the main opportunities to tackle hunger and protect lives and livelihoods in the region. However, with fall armyworm having a preference for maize and other cereals, an outbreak threatens to further undermine the food security of families that can ill afford another crisis. The pest is known to cause 100 percent crop losses.

There is urgent need therefore to support the county and national governments to halt further spread and damage. Failure to control the pest would result in serious food, economic and social insecurity in Kenya, and indeed in Eastern and Central Africa.

On 25 April 2017, FAO convened a technical meeting in Nairobi, Kenya to deliberate on the fall armyworm response with the Governments and partners in Southern Africa. The outcomes of this meeting were then deliberated at an Africa-wide meeting organized by FAO, the Alliance for a Green Revolution and the International Maize and Wheat Improvement Centre in Nairobi on 27 and 28 April. The meeting reviewed the status of fall armyworm incidence and impact in Africa, discussed the available technological options for minimizing the damage caused by the pest and provide concrete recommendations on the strategy for effective management of fall armyworm in Africa. The meeting will also identify appropriate partnerships to develop and deploy short, medium and long-term solutions to the farming communities in Africa.

Kiwi bacteriosis

fresh plaza logo

Kiwi bacteriosis control now a reality

The international Journal of Plant Disease and Protection finally published the research financed by MIPAAF and coordinated by Prof. Giorgio M. Balestra which saw the cooperation between the Department of Agricultural Sciences (DAFNE) of Università della Tuscia and the Department of Life Sciences and Biotechnology (SVeB) of the University of Ferrara

Title: “Microparticles containing gallic and ellagic acids for the biological control of bacterial diseases of kiwifruit plants

Authors: Antonio Rossetti, Angelo Mazzaglia, Massimo Muganu, Marco Paolocci, Maddalena Sguizzato, Elisabetta Esposito, Rita Cortesi, Giorgio Mariano Balestra.

It is a lengthy study that demonstrates how it is possible to use vegetable substances to monitor the different phytopathogenic bacteria that cause much worry in all the areas growing Actinidia spp..

The cultivation of actinidia to produce kiwis has become increasingly important in Italy as well as in various areas around the world. At the same time, however, bacterial diseases are affecting its cultivation. The most dangerous is without doubt the bacterial canker caused by Pseudomonas syringae pv. actinidiae (Pss) Takikawa et al., also known as Psa, which damages all vegetative organs.

Serious damage is caused also by the drop in temperatures in spring, as is the case this year, associated with other two bacteria – Pseudomonas syringae pv. syringae (Pv) van Hall, responsible for floral bud necrosis and Pseudomonas viridiflava (Burkholder) Dowson, the bacterial blight which affects leaves and floral organs.

In Italy, prevention is carried out by using copper salts as well as a biological control agent (B. a. subsp. plantarum ceppo D747) during blossoming. Other areas outside the EU employ antibiotics with serious repercussions on the environment and leading to the development of antibiotic-resistant bacteria strains.

This study assessed the effectiveness of gallic and ellagic acids, i.e. natural substances that are easily attainable from many vegetable tissues and with high anti-microbial properties.

These natural, active principles proved effective as pure substances both in the lab and in vivo (greenhouses, then open-field actinidia orchards naturally affected by Pss, Pv and Psa).The vegetable active principles significantly reduced the various bacterial populations as well as the damage caused both through artificial contamination and by using them on orchards naturally affected by Pss, Pv and Psa.

In association with the intrinsic activities, the active principles proved particularly effective when employed through micro-formulations in micro-capsules, thus preventing alterations (physical-chemical) and enabling a controlled release of the principles over two weeks protecting all vegetable organs.

In addition, the activity of these formulations on both plant development and final production was also assessed. All parameters showed how these micro-formulations do not affect plant development (the plants treated with micro-capsules had a higher chlorophyll content in the leaves and the fruits, though with the same size and Brix level, were more compact).

The results obtained with this study represent a significant contribution towards the attainment of formulations that can successfully counter dangerous micro-organisms like those affecting actinidia with a sustainable/organic approach.

Reducing the use of copper salts to protect crops is a process dictated by the EU. As of January 2018, further reductions of Cu++ will be introduced, thus valid alternatives must be found.

This study suggests how gallic and ellagic acids, when formulated together in microformulations, can be successfully employed in sustainable/organic defence strategies against pathologies like those currently affecting actinidia.

The active principles and technology used in this research constitute an important base, as what described can be applied to different pathogens/ crops, thus reducing the use of chemicals and therefore chemical residue.

Additional studies are currently being carried out concerning organic nano-formulations for the protection of different crops both in the fields and during the storage and commercialisation stages. They aim at a further reduction of the (natural) active principles used, at a prolonged controlled release and at making it so that formulations can penetrate fruit/plants and target the pathogen.

For further information:
Prof. Giorgio M. Balestra
DAFNE (Department for Agriculture, Forestry, Nature and Energy)
University of Tuscia
Via S. Camillo de Lellis
01100 Viterbo
Tel.: (+39) 0761 357474
Cell.: (+39) 333 4246404
Fax: (+39) 0761 357473
Email: balestra@unitus.it
Web: www.unitus.it
Skype: giorba5618
Personal page: www.dafne.unitus.it/web/interna.asp?idPag=1118

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Plant disease patterns offer clues about climate change

By Tim Sandle     May 20, 2017 in Environment

General atmospheric models provide an indicator of climate change. More sensitive models are needed to understand what is happening on ground level, however. One way to do this, new research highlights, is by tacking the spread of plant pathogens.

The research focuses on understanding climate change on agroecosystems (the ecology of agriculture). This is specifically thorough charting the effects of temperature change upon leafhopper vector behavior, which relates to the spread of Pierce’s disease on grapevines. The headline finding from the research is that global warming exacerbates the disease symptoms seen with infected grapevines.

Pierce’s disease is caused by a bacterium called Xylella fastidiosa. The disease is endemic in northern California, being spread by the blue-green sharpshooter, which only attacks grapevines. Vines become damaged through the bacterium causing a gel to form in the xylem tissue of the vine. This prevents water from being drawn through the vine. In terms of symptoms, the leaves become slightly yellow or red along margins in white and red varieties. This is followed by fruit clusters shriveling or becoming raisin-like.

The new connections have been made based on a mix of biology field work together with a mathematical model. The study has been led by University of California, Riverside entomologist Dr. Matthew Daugherty. The factors considered in the research included the type of disease, the insect vector, and temperature. The research shows how rising temperatures led to variable effects in relation to vectors of diseases (in this case, insects spreading plant diseases).

The data indicates while global warming increases the types of disease symptoms seen with infected grapevines there could also be a limit to the extent that the insects that spread the disease will function under the higher temperatures. This is because the insects do not like feeding on vines that show extensive signs of the disease. In other words, the infections that grape vines contract might become worse but the rate of infection may slowdown.

As Dr. Daugherty explains: “Because the leafhopper vectors of the Pierce’s disease pathogen avoid feeding on diseased vines, pathogen spread declined over time at higher temperatures.” In this sense climate change introduces both a negative effect (a more virulent pathogen) and a positive effect (a reduction in vine infections).

The research is published in the journal Phytobiomes, with the research paper titled “Conflicting Effects of Climate and Vector Behavior on the Spread of a Plant Pathogen.”

Read more: http://www.digitaljournal.com/news/environment/plant-disease-patterns-offer-clues-about-climate-change/article/493107#ixzz4hqAfynmq

terradaily-454

Scientists suggest the world should brace itself for a new wave of biological invasions

FLORA AND FAUNA

Scientists suggest the world should brace itself for a new wave of biological invasions
by Staff Writers
Cambridge UK (SPX) May 04, 2017

A global invasion.

We are all becoming increasingly familiar with the impacts of invasive species. Knotweed from Japan can destroy building foundations, zebra mussels from eastern Europe can clog-up drinking water pipes, and an Asian fungus is causing ash tree die-back in our forests. Now an international team of scientists has identified how our rapidly changing world will bring new types of invaders, often from very unexpected places.

non-native-plantings-have-impact-on-diversity-insect-populations-lg

Invasive non-native species are among the greatest drivers of biodiversity loss on the planet and cost the British economy Pounds 1.7bn each year. “Our study found that environmental change, new biotechnology and even political instability are all likely to result in new invasions that we should all be worried about” said Dr. David Aldridge of Cambridge University, who hosted the meeting of 17 scientists from across four continents.

Globalization of the Arctic, emergence of invasive microbial pathogens, advances in genomic modification technology, and changing agricultural practices were judged to be among the 14 most significant issues potentially affecting how invasive species are studied and managed over the next two decades. “We have identified some potential game-changers” said Prof. Anthony Ricciardi from McGill University, who led the study.

Globalization of the Arctic
Until now, the Arctic has been among the least accessible regions on the planet, escaping extensive alien species invasions like those that have affected temperate and tropical areas of the world. However, the rapid loss of sea ice is opening the region to shipping, oil and mineral extraction, fishing, tourism, and shoreline development – all of which facilitate introductions of alien species.

The loss of sea ice is also creating a major new corridor for international shipping between the Pacific and Atlantic Oceans, which will affect invasion risks throughout the Northern Hemisphere. “The gold rush has begun for major expansion of human activities in the Arctic, with the potential for large-scale alien species transfers” says Dr. Greg Ruiz (Smithsonian Environmental Research Center).

Emergence and spread of invasive microbial pathogens
Disease-causing bacteria, water molds, fungi and viruses are being given increasing opportunities to spread into regions where they never previously existed and where they may attack new hosts. They can also undergo rapid genetic changes that cause previously innocuous forms to become virulent.

Invasive microbes have devastated populations of animal and plants that have had no evolutionary exposure and thus no immunity to them.

Recent examples include: the chytrid fungus “Bsal” that is killing salamanders in Europe; the white-nose fungus that is destroying bat colonies in North America; and sea star wasting disease along the Pacific coast of North America, considered to be among the worst wildlife die-offs ever recorded. The proliferation of microbial pathogens is a burgeoning threat to biodiversity, agriculture, forestry and fisheries.

Biotechnological advances and applications
Advances in genomic modification tools hold both promise and challenges for managing invasive species. Very recently, genetically modified versions of an invasive mosquito were released in the Florida Keys in a controversial attempt to interfere with the mosquito’s reproductive life cycle, thereby preventing it from vectoring the spread of invasive Zika, Dengue and Chikungunya viruses to humans.

“The push to use genetically modified agents to control invasive species will continue to grow”, says Prof. Hugh MacIsaac (University of Windsor), “and with it will come public opposition and the view that we are opening Pandora’s Box”.

Changing agricultural practices
The team also identified changing agricultural practices as a potential source of invasion threats. Virtually unregulated new agricultural crops and practices open the door to potentially disastrous unintended consequences. An Asian cricket species reared for “cricket flour” – all the rage in the USA – has already established in the wild. Worse, as a disease ravages this species, farmers have imported other kinds of crickets that might well invade in nature.

But possibly the biggest threat of all is the growing use by agribusiness of soil bacteria and fungi to increase crop production. “The cultivation and distribution of ‘growth enhancing’ microbes could cause some crop plants or plant species residing near agricultural fields to become invasive pests” says Prof. Daniel Simberloff (University of Tennessee).

Invasive species denialism
An additional challenge is public perception of invasion science. Scientific evidence on invasive species impacts is under attack, with much of the opposition value-based rather than science-based. This form of science denialism involves a rejection of peer-reviewed evidence along with an attempt to re-frame, downplay or even deny the role of invasive alien species in global environmental change.

“Denialism in science is not new, but its growth in the context of invasive species is especially worrying for people trying to conserve unique native biodiversity” says Prof. Tim Blackburn (University College London). “Manufacturing doubt about the negative impacts of invasive species can delay mitigating action to the point where it is too late.”

Research paper