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Myzus persicae (green peach aphid); an alate (winged) adult

Myzus persicae (green peach aphid); an alate (winged) adult

Recent research highlights why the green peach aphid (Myzus persicae) is one of the most successful crop pests. These findings will help further the development of effective management and control measures which will ultimately reduce worldwide crop losses.

The green peach aphid is one of the most challenging crop pests, living on hundreds of host plants in over 40 families. This makes it an impressive generalist compared to many other aphids, a large number of which are only adapted to survive on one species. Key crops impacted by this pest include sugar beet, beans, potato, tomato and oilseed rape.

So how can it be such a wide ranging generalist? Recent research, carried out by the Earlham Institute (EI) and John Innes Centre (JIC) in the UK, has found that its ability to survive on so many hosts is largely down to its genetic plasticity (Mathers et al., 2017). After just two days, scientists were able to see that genes responsible for helping aphids adjust to different plants rapidly increased or decreased in activity when an individual was moved to a different host.

Interestingly, it seems that many of the genes involved are not specific to this species of aphid, but that the green peach aphid is just particularly well adapted to adjusting to the expression of the key genes.

Not only can it adapt well to different hosts, the pest transmits over 100 plant virus diseases, including Beet western yellows virus, Bean leaf roll virus and Potato leaf roll virus. Losses caused by these plant diseases can be very high – sugarbeet losses due to beet yellows can be up to 50%. Furthermore, the green peach aphid has developed resistance to over 70 different pesticides, making it difficult to control.

Then there’s its ability to reproduce prolifically. Females can give birth to females without mating with a male (clonal reproduction). Consequently green peach aphids can have up to 30 generations a year (Texas A&M University, 2017).

All in all, it’s no wonder that the green peach aphid is such an incredibly successful pest, unfortunately causing major widespread damage every year. This latest research is a significant step towards understanding how the pest is so successful, paving the way for more effective management and control methods.

For more information, read How to be a successful pest: lessons from the green peach aphid by the Earlham Institute.

You can also find out information regarding the green peach aphid on our Plantwise Knowledge Bank.

CABI, 2017. Green peach aphid (Myzus persicae). In: Plantwise Knowledge Bank. Wallingford, UK: CAB International. http://www.plantwise.org/knowledgebank/datasheet.aspx?dsid=35642

Earlham Institute, 2017. How to be a successful pest: lessons from the green peach aphid. UK: Earlham Institute. http://www.earlham.ac.uk/how-be-successful-pest-lessons-green-peach-aphid

Mathers TC, Chen Y, Kaithakottil G et al., 2017. Rapid transcriptional plasticity of duplicated gene clusters enables a clonally reproducing aphid to colonise diverse plant species. Genome Biology, 18:27.

Texas A&M University, 2017. Green Peach Aphid. In: Texas A&M Agrilife Extension Series. Texas, USA: Texas A&M University. http://texasinsects.tamu.edu/aimg103.html


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Zoutnet
https://www.zoutnet.co.za/articles/news/40825/2017-02-13/dreaded-fall-armyworm-is-here

Dreaded fall armyworm is here

News Date: 13 February 2017

Written by: Prudence Bopape / Viewed: 260

A dreaded pest, the fall armyworm, has arrived in Limpopo, much to the dismay of crop farmers and the Department of Agriculture, Forestry and Industries (DAFF). The armyworm can destroy massive quatities of crops in a matter of days and the normal pesticides are not very effective in combatting it.

The department has warned Limpopo residents about this alien creature and has stated in a press release that researchers are currently working on a plan to resolve this issue. It has been confirmed that these armyworms have already damaged maize in South Africa’s Limpopo, North West and Free State provinces.

The fall armyworm was positively identified from samples collected in Limpopo. These samples were jointly collected by scientists from ARC Grain Institute and the Northwest University.

The DAFF warned that the worm poses a great danger to the livelihood of the growth and development of crops and other plantations. Armyworms primarily feed on grass, forage grasses, oats, wheat and corn. These pests attack vegetables such as beans, cabbages, onions, peas, peppers and sweet potatoes.

“As the fall armyworm is a new pest to South Africa, no pesticide was previously registered to be used against it. A process of emergency registration of agricultural chemicals is initiated for urgent registration,” said Miss Bomikazi Molapo, spokesperson for the department.

Farmers as well as other individuals need to stay alert as these armyworms come in different colours from greenish-brown to black. These creatures reach a level of maturity at the length of 1½ inches. The eggs resemble globules as they are laid in rows on groups of host plants.

The presence of the pest will be notified on the International Plant Protection Convention’s portal in terms of South Africa’s international pest-reporting obligations. SADC member countries will also be notified and regional control measures will be discussed.

Crop producers are encouraged to report suspected detection of this pest to the department. Please report to Jan Hendrik Venter at: 012 3196384, 0723488431 or janhendrikv@daff.gov.za. “Please contact a chemical representative to advise with control options,” the department said.

By Nilesh Christopher. Reblogged from The Economic Times of India. Before the start of the next crop planting season, third generation farmer Krishna Balegayi – who has been farming for 25 years – is sure to take the help of an Android app to better his yield. Bangalore-based startup Nubesol technologies has created a WhatsApp-like […]

via A WhatsApp-like app for the tech-savvy farmer — The Plantwise Blog

Scientific Modeling Helps Defend Tomatoes Against Flying Foe

January 31, 2017
IPM Innovation Lab Director Muni Muniappan inspects tomatoes damaged by Tuta absoluta in Puranchaur, Nepal. The pest was first reported in the country in spring of 2016, and it is already promising to be a big problem for the upcoming tomato-growing season.

Tomatoes are so abundant that they can be easy to take for granted. But a pest known as the South American tomato leafminer, or Tuta absoluta, has been making this popular ingredient harder to find in countries throughout the world. The tomato leafminer hasn’t arrived in the United States yet, but it has made it as far north as Costa Rica. Now, most scientists agree, it’s no longer a question of if this pest will arrive, but when.

“People want to know when Tuta will be in the United States,” said Muni Muniappan, director of the Feed the Future Innovation Lab for Integrated Pest Management, led by Virginia Tech University. “It could be in 1 year or 10 years, but eventually it will be here.”

Fresh and processed tomatoes generated $2 billion dollars in the United States in 2015 and tomato exports totaled $335 million, making America the seventh largest tomato-producing country in the world. An invasion by the tomato leafminer could put a serious dent in those numbers.

Muniappan and the Integrated Pest Management Innovation Lab have been working to combat the pest since it hitched a ride to Spain in 2006, where it then spread through Europe and the Mediterranean and into Central and South Asia and parts of Africa.

“There is no silver bullet for Tuta absoluta,” Muniappan said. “We cannot stop it, but we can slow it down.”

Under these circumstances, the best way to protect countries that have not been reached by the pest is to delay its arrival and increase awareness about it. Then, if it does arrive, the key is to limit its damage with a quick response.

To keep the pest out of America for as long as possible, the Integrated Pest Management Innovation Lab is helping monitor Tuta absouta and assist states in using pheromone traps for early detection. It is also working with Costa Rica to suppress the pest and prevent its northward spread.

When the pest does inevitably enter the United States, quarantine measures will be necessary. To this end, the Integrated Pest Management Innovation Lab recently gave funding to Virginia Tech’s Biocomplexity Institute to model the spread of Tuta absoluta, using human movement as a variable. Most models use only temperature and weather patterns as predictors of disease and pest spread, but the model developed through this project will also consider popular trade and travel routes.

“Our model will be an extremely useful tool to develop strategies to combat these pests,” said Abhijin Adiga, a research faculty member at the Biocomplexity Institute and project lead. “Further, the methodology will not be limited to studying the tomato leafminer but can be applied to any agricultural invasive species.”

Muniappan and the Integrated Pest Management Innovation Lab are raising awareness in America and around the world about the pest. So far, they’ve held 16 international awareness workshops, reaching scientists from 55 countries. At the International Congress of Entomology in October 2016 in Florida, the Feed the Future Innovation Lab led a symposium, resulting in the group recommending several measures, such as undertaking a concentrated effort to look for natural enemies in Tuta’s area of origin in South America and providing information on appropriate insecticide rotations for pest management in the fields.

“With proactive actions,” Muniappan said, “we hope to significantly reduce the economic loss caused by this pest in the United States and around the world.”

Southeast

Farm Press

cotton-seedling-GA-2016-a
From whiteflies in southern Georgia to bollworms in North Carolina to plant bugs in Virginia, 2016 was certainly a challenging insect year for cotton growers across the Southeast, and 2017 is expected to be no different.

John Hart | Feb 08, 2017

From whiteflies in southern Georgia to bollworms in North Carolina to plant bugs in Virginia, 2016 was a challenging insect year for cotton growers across the Southeast. Dominic Reisig is urging farmers to be prepared for another challenging year.

Reisig, North Carolina State University Extension entomologist, addressed “Emerging Insect Issues in the Southeast” at the annual meeting of the Southern Cotton Growers and Southeastern Cotton Ginners in Charlotte, N.C., Jan. 20, where he provided an insect situation, outlook report and control recommendations.

“Thrips are probably our biggest pest problem in the upper Southeast. When you think about the tough environment you have to plant cotton in early season, the conditions can be brutal,” Reisig said.

With the loss of Temik, North Carolina farmers thought they had a good replacement for thrips control with the use of an infurrow application of Admire Pro along with an insecticidal seed treatment.

“One of the things we are preaching to our growers is to load up on active ingredients,” Reisig said. “We think seed treatments still have value even though we have this resistance situation. We’re recommending to our growers still use these insecticides but don’t expect them to perform as they have in the past.”

“Injury is a function of weather: how fast is that plant goring to grow, how many thrips are out there,” Reisig explained. “This model will actually predict when thrips are dispersing and when they are going to be on the plant and what’s the weather going to do. It will give you a red light or a green light, those are the different planting dates. We’re going to be able to tell growers if at this location you plant cotton at this date, you’re going to be safe from thrips.”

As for whiteflies in Georgia, Reisig said a new species has been detected, the silver leaf whitefly which is difficult to control and requires the use of expensive insecticides, compared to the more common banded wing whitefly which is easier to control.

“The problem with whiteflies is they are not mobile,” Reisig said. “They stick on the bottom of the leaves and tap into the veins of the plant and they basically get too much sugar. They drop it onto the cotton and cause a great deal of loss that way. When the cotton opens up, the lint get colonized and black mold or sooty mold makes the cotton sticky.”

In North Carolina, bollworms were a major midseason pest in 2016 due the increased planting of corn relative to cotton. Reisig explains the cotton bollworm uses corn as an early season host. “If there’s a lot of early season hosts out there, you’re probably going to get a lot of cotton bollworm coming out of the corn and moving into your cotton,” he noted.

In addition, true Bt resistance in cotton is becoming a problem. However, Reisig said Bt cotton still has a place because it delivers other advantages such as excellent tobacco budworm control.

Finally, Reisig notes that plant bugs have now moved into Virginia in addition to becoming a bigger issue in North Carolina.

“When I started in 2009, I was told plant bugs were not an issue in North Carolina cotton. They have become an increasing issue year after year and we’re not exactly sure why,” he said.

“In northeastern North Carolina, plant bugs are a problem in nearly every field. Three-fourths of our fields are getting sprayed for plant bugs. We’ve increased the number of sprays on the fields, averaging two sprays for every field.”

Reisig believes plant bugs are showing resistance to pyretheroids in North Carolina which is why rotating chemistries is critical. In addition, plant bugs are liked to bollworms in cotton

“For a pest like plant bugs, what you really want to do is you want to control it early season before cotton blooms because a plant bug uses its mouth parts to feed on a square,” Reisig explained. “If it feeds on a square, the square will fall off and you won’t have any flowers left to make bolls. When you spray cotton early season to control plant bugs, you knock out natural enemies that then control bollworms later on in the season.”

Reisig is recommending the insecticide Diamond for plant bug control this year. “Diamond is a unique chemistry because it is an insect growth regulator. Insect growth regulators are only active on nymphs but they tend in the Mid-South to extend the period of control so you don’t have to spray as much,” he said.

Global spead of wheat rust

Spread of damaging wheat rust continues: new races found in Europe, Africa, Central Asia

Mediterranean particularly affected by new rust races

Photo: ©FAO/ Fazil Dusunceli

Wheat experts examine a research plot near Izmir, Turkey, affected by wheat yellow rust.

3 February 2017, Rome −  Wheat rust, a family of fungal diseases that can cause crop losses of up to 100 percent in untreated susceptible wheats, is making further advances in Europe, Africa and Asia, according to two new studies produced by scientists in collaboration with FAO.

The reports, highlighted in the journal Nature following their publication by Aarhus University and the International Maize and Wheat Improvement Center (CIMMYT), show the emergence of new races of both yellow rust and stem rust in various regions of the world in 2016.

At the same time, well-known existing rust races have spread to new countries, the studies confirm, underlining the need for early detection and action to limit major damage to wheat production, particularly in the Mediterranean basin.

Wheat is a source of food and livelihoods for over 1 billion people in developing countries. Northern and Eastern Africa, the Near East, and West, Central and South Asia – which are all vulnerable to rust diseases − alone account for some 37 percent of global wheat production.

“These new, aggressive rust races have emerged at the same time that we’re working with international partners to help countries combat the existing ones, so we have to be swift and thorough in the way we approach this,” said FAO Plant Pathologist Fazil Dusunceli. “It’s more important than ever that specialists from international institutions and wheat producing countries work together to stop these diseases in their tracks −  that involves continuous surveillance, sharing data and building emergency response plans to protect their farmers and those in neighboring countries.”

Wheat rusts spread rapidly over long distances by wind. If not detected and treated on time, they can turn a healthy looking crop, only weeks away from harvest, into a tangle of yellow leaves, black stems and shriveled grains.

Fungicides can help to limit damage, but early detection and rapid action are crucial. So are integrated management strategies in the long run.

wheat_stem-rust_1Stem rust

Mediterranean most affected by new rusts

On the Italian island of Sicily, a new race of the stem rust pathogen −called TTTTF− hit several thousands of hectares of durum wheat in 2016, causing the largest stem rust outbreak that Europe has seen in decades. Experience with similar races suggests that bread wheat varieties may also be susceptible to the new race.

TTTTF is the most recently identified race of stem rust. Without proper control, researchers caution, it could soon spread over long distances along the Mediterranean basin and the Adriatic coast.

Various countries across Africa, Central Asia and Europe, meanwhile, have been battling new strains of yellow rust never before been seen in their fields.

Italy, Morocco and four Scandinavian countries have seen the emergence of an entirely new, yet-to-be-named race of yellow rust. Notably, the new race was most prevalent in Morocco and Sicily, where yellow rust until recently was considered insignificant. Preliminary analysis suggests the new race is related to a family of strains that are aggressive and better adapted to higher temperatures than most others.

Wheat farmers in Ethiopia and Uzbekistan, at the same time, have been fighting outbreaks of yellow rust AF2012, another race which reared its head in both countries in 2016 and struck a major blow to Ethiopian wheat production in particular. AF2012 was previously only found in Afghanistan, before appearing in the Horn of Africa country last year, where it affected tens of thousands of hectares of wheat.

“Preliminary assessments are worrisome, but it is still unclear what the full impact of these new races will be on different wheat varieties in the affected regions,” said Dusunceli. “That’s what research institutions across these regions will need to further investigate in the coming months.”

To offer support, FAO, in collaboration with its partners, is stepping up its efforts in training rust experts from affected countries to boost their ability to detect and manage these emerging wheat rust races.

As new races emerge, old ones continue to spread

The already established Warrior(-) race of yellow rust − which came onto scientists’ radars in Northern Europe and Turkey a few years ago −  continued its aerial march in 2016 and is now widely present in Europe and West Asia.

The Digalu (TIFTTF) race of stem rust continues to devastate wheats in Ethiopia, while the most well-known race of stem rust – the highly potent Ug99 – is now present in 13 countries. Having spread in a northward trend from East Africa to the Middle East, Ug99 has the potential to affect many wheat varieties grown worldwide as it keeps producing new variants. Most recently, it has been detected in Egypt, one of the Middle East’s most important wheat producers.

International collaboration crucial

The findings of the Aarhus study build on training sessions conducted in 2016 in collaboration between the International Center for Agricultural Research in the Dry Areas (ICARDA), Aarhus university, CIMMYT and FAO.

The training, which will be repeated this year, allows rust experts to strengthen their surveillance and management skills, coupled with surveys and collection of rust samples for tests and analysis by Aarhus University. The recently established Regional Cereal Rust Research in Izmir, Turkey, will host the training.

These efforts have been part of FAO`s four-year global wheat rust program, which facilitates regional collaborations and offers support to individual countries eager to boost their surveillance capacity.

It also helps countries act swiftly to control outbreaks before they turn into epidemics and cause major damage to food security. But further research, particularly into breeding resistant varieties, and national response plans need to be backed by adequate resources.

FAO, CIMMYT, ICARDA and Aarhus University are working together as members of the Borlaug Global Rust Initiative (BGRI).

BBC
http://www.bbc.com/news/world-latin-america-38914922

 locust-bolivia
Image copyright AP

Image caption Locusts are normally solitary, but can swarm under certain conditions

The Bolivian government has declared a state of emergency in a vast agricultural area affected by a plague of locusts.

President Evo Morales has announced a contingency plan, which includes $700,000 in extra funds for fumigation.

The swarm first appeared over a week ago near the low-lying eastern city of Santa Cruz, where most of Bolivia’s food and meat is produced.

It has spread quickly, destroying pasture and fields of corn and sorghum.

The authorities estimate more than 1,000 hectares of agricultural land have been devastated by the locusts.

The government says fumigation must begin straight away.

“We will create a 500-metre-wide ring around the area affected and fumigate inside, working alongside the local authorities,” said Bolivia’s Agriculture Secretary, Mauricio Ordonez.

Mr Morales is due to visit Santa Cruz province on Friday.