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Fall armyworm ‘worsens hunger among smallholders’

maize farm

Maize farmer inspecting her crops. Copyright: Axel Fassio/CIFORCC BY-NC-ND 2.0

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  • Fall armyworm destroys maize worth almost US$5 billion annually in 12 African countries
  • In a Zimbabwe study, the pest increased likelihood of hunger by 12 per cent
  • Farmers need cost-effective, environmentally sustainable control measures, experts say
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By: Onyango Nyamol

[NAIROBI] The invasive crop pest fall armyworm is well known for its devastating effects on maize yields in Africa, but few studies have been done on its broader impact on poverty levels and food security.

Now a study in Zimbabwe has found that smallholder maize-growing households blighted by fall armyworm are more likely to experience hunger and could see their income almost halved in severe cases, highlighting the urgency of strategies to tackle the pest.

“Our study suggests that the outbreak is threatening food security and negatively affecting farmers’ livelihoods, hence urgent actions are needed.”

Justice Tambo, CABI

According to the study, estimates from 12 maize‐producing countries in Sub-Saharan Africa including Benin, Cameroon, Ethiopia, Ghana, Malawi, Mozambique, Nigeria, Tanzania, Uganda, Zambia and Zimbabwe indicate that without control measures, the pest could cause maize losses of up to 17.7 million tonnes, translating into revenue loss of up to almost US$5 billion a year.

But researchers say that the negative impacts of the pest are far more than yield losses, with the potential to significantly impact food security and livelihoods.

The study, published in Food and Energy Security last month (15 March), shows that households affected by fall armyworm were 11 per cent more likely to experience food shortages, while their members had a 13 per cent higher likelihood of going to bed hungry or a whole day without eating. It also found that found that severe levels of infestation reduced per capita household income by 44 per cent.

“Our study suggests that the outbreak is threatening food security and negatively affecting farmers’ livelihoods, hence urgent actions are needed to address the menace posed by fall armyworm,” says Justice Tambo, the study’s lead author and a socio-economist at the Centre for Agriculture and Bioscience International (CABI, the parent organisation of SciDev.Net).

According to the study, fall armyworm was first reported in Zimbabwe during the 2016 and 2017 cropping season, and has continued to spread in subsequent seasons.

Researchers used survey data from 350 smallholder maize-growing households in six of Zimbabwe’s main maize production provinces. Data was collected in September 2018 by CABI in collaboration with Zimbabwe Plant Quarantine and Plant Protection Research Services Institute.

“We decided to conduct this study to provide evidence [of] how the fall armyworm outbreak is affecting farmers’ livelihoods beyond reductions in maize yields,” Tambo says. “While fall armyworm cannot be eradicated, taking actions to at least prevent severe level of infestation can significantly reduce welfare losses in terms of income and food security.”

Boddupalli Prasanna, director of the global maize programme at the International Maize and Wheat Improvement Center, tells SciDev.Net that fall armyworm is a serious concern to resource-constrained smallholders who have multiple challenges to tackle.

“We certainly need to provide effective, scalable and affordable technologies to the farming communities to combat the pest in a sustainable manner. Farmers cannot afford to rely on expensive chemical pesticides to and control fall armyworm,” says Prasanna, who was not involved in the study.

https://www.buzzsprout.com/1257893/8247114-in-africa-music-is-life-and-health?client_source=small_player&iframe=true&referrer=https://www.buzzsprout.com/1257893/8247114-in-africa-music-is-life-and-health.js?container_id=buzzsprout-player-8247114&player=small
Prasanna adds that there is no single specific technology that can provide sustainable control of a pest like fall armyworm.

“We need to adopt an integrated pest management (IPM) strategy, including effective integration of improved varieties with resistance to the pest, environmentally safer pesticides, biological control … and good agronomic practices,” he says. “We need to [increase] extensive awareness among extension agents and farming communities about IPM strategy for the control of fall armyworm.”

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According to Tambo, the findings have implications for policymakers, researchers and farmers. Farmers need to adopt low-risk pesticides products such as biopesticides, and combine them with safe non-chemical options including rotation and intercropping with other crops such as beans and cassava, he explains.

This piece was produced by SciDev.Net’s Sub-Saharan Africa English desk.

References

Justice A. Tambo and others Impact of fall armyworm invasion on household income and food security in Zimbabwe (Food and Energy Security, 15 March 2020)

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The humble beetle that could rescue a town Share using EmailShare on TwitterShare on FacebookShare on Linkedin(Image credit: Alamy)

Salvinia has an enormously rapid growth rate and can engulf a lake, smothering the ecosystem and killing fish and mammals (Credit: Alamy)

By Nalova Akua29th March 2021An invasive water weed has decimated the wildlife and economy of one of Cameroon’s most significant lakes. But a tiny, ravenous weevil could reverse the region’s fortunes.A

A flock of water birds scavenges for insects on the dense, leafy weed that covers much of Lake Ossa, one of Cameroon’s largest lakes. The water weed is so closely packed that it looks like wide, flat green pasture, and the sure-footed birds pick their way freely across it as if they were walking on land.

Five years ago, Lake Ossa was teeming with freshwater turtles, crocodiles and more than 18 families of fish. It was also a bastion of the African manatee, a species listed as vulnerable on the International Union for Conservation of Nature’s Red List. But today, the lake is eerily quiet and almost empty.

The thick layer of vegetation is Salvinia molesta, a species known locally as kariba weed or simply Salvinia, and it is the cause of this dearth of life in the lake. The invasion has been declared a “conservation emergency” by the IUCN.

Salvinia, a free-floating, green-brown freshwater fern, has already invaded more than 40% of the lake’s 4,000-hectare (15.4-sq-mile) surface, according to the African Marine Mammal Conservation Organisation (AMMCO), a Cameroonian non-governmental environmental organisation.

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Not far from the lake’s shore, an army of weevils is now being mass-reared as a defence against Salvinia

Decimating the lake’s wildlife, and compromising the main source of income for the local population, the Salvinia takeover has been rapid and seemingly unstoppable. Lake Ossa is only one in a long line of freshwater bodies to be engulfed by Salvinia. As this invasive weed has spread around the world, from Brazil and Argentina to Australia, the efforts to control it have struggled to keep pace with the plant’s prolific growth.

But there is hope for Lake Ossa, and it comes in the shape of a small, innocuous-looking but remarkably powerful water-dwelling beetle. Not far from the lake’s shore, an army of weevils is now being mass-reared as a defence against Salvinia.Lake Ossa is one of the largest lakes in Cameroon, and was home to a wealth of biodiversity before Salvinia arrived (Credit: AMMCO)

Lake Ossa is one of the largest lakes in Cameroon, and was home to a wealth of biodiversity before Salvinia arrived (Credit: AMMCO)

Lake Ossa is today littered with weed-laden fishing nets – abandoned by the local fisherfolk out of frustration. Wooden fishing boats have been hauled onto the lake’s shorelines – some have been there so long they are starting to rot. Those local fishermen who are still actively fishing in the lake, and the women who sell the fish caught, say they have lost about 80% of their income.

Lake Ossa used to be home to scores of African manatees, one of the most sparsely studied manatee species. Their population in the lake now appears to be declining

In the sweltering late morning heat, I meet Dina Marie-Louise, a fish retailer and resident of the lakeside town of Dizangue, as she disembarks from a wooden fishing boat. In the local business for 22 years, Dina has been visiting fishermen in the lake to buy their catch. Today, she frowns at the few fish in her basket. “Salvinia is killing us,” she says. “Seven of my 12 children have dropped out of school because of financial difficulties caused by Salvinia.”

Roland Ngolle, who has been fishing in the lake for 12 years, paints a similar picture. “We are running out of space to fish in this lake. If nothing is done, Salvinia will engulf all of Lake Ossa,” Ngolle says. “More than 100 fishermen used to visit this lake in a single morning. Today less than five come to fish. Everybody is discouraged.”

As well as fish, Lake Ossa used to be home to scores of African manatees, one of the most sparsely studied manatee species. Their population in the lake now appears to be declining. Many of the manatees are thought to be leaving the lake for its surrounding rivers, where they have better access to food, says Aristide Takoukam Kamla, founder of AMMCO.The larvae of the Salvinia weevil are highly destructive and can bring a freshwater habtitat back into ecological balance (Credit: Alamy)

The larvae of the Salvinia weevil are highly destructive and can bring a freshwater habtitat back into ecological balance (Credit: Alamy)

Salvinia is native to southern Brazil and northern Argentina, but it can spread between water bodies by wind, water currents, floods, animals and people. “[The] human factor is partly to blame for the presence of the invasive plant in the Cameroon lake,” says Kamla.

As well as physically moving the plant from one place to another, for example when it hitches a ride on boats, human activity is also thought to be responsible for allowing Salvinia to thrive in the lake.

“We noticed a heavy concentration of nutrients such as nitrogen and phosphorous in Lake Ossa in 2016 – doubling from the historical value of 1985,” says Kamla. “This was a signal that something was happening in the lake called eutrophication, which is simply the enrichment of the lake in terms of nutrients.”

That made conditions perfect for Salvinia to proliferate. “The carpet formed by the plant at the surface prevents light from penetrating the water column and therefore reduces photosynthesis of phytoplankton on which most fish species feed,” says Kamla. “This results in a drastic depletion of fish production.”

With a fast-growing plant that can double in size every 10 days, the plant’s growth is almost unstoppable. “The absence of [Salvinia’s] natural enemies in a foreign environment facilitates its fast growth rate,” says Lum Fontem, an independent plant scientist based in Cameroon.Numbers of the African manatee, pictured here in captivity, are in decline (Credit: Getty Images)

Numbers of the African manatee, pictured here in captivity, are in decline (Credit: Getty Images)

At every strategic corner of the bumpy earth roads around Dizangue, billboards carry messages alerting villagers and visitors to the Salvinia problem. Messages such as “Youths, Let’s Save Lake Ossa”; “Let’s Save Our Lake From Salvinia Invasion” appear on countless signs around the town. This may be Cameroon’s first experience of a Salvinia invasion, but there has already been an intensive response to it.

There are three main ways that the weed can be removed. The first, and most physically demanding, is removing it manually. “This includes hand-pulling, mostly for low infestation, and the use of specialised equipment, for high infestation,” says Fontem. “This method is labour-intensive, tedious and time-consuming.”

Since 2019, AMMCO has been mobilising locals to remove the plant manually to reduce the scope of spread. But it has not been without challenges. “This method is very demanding given that the invasive plant multiplies very quickly,” says Kamla. “We removed over 200 tonnes of Salvinia from the lake in 2019 and 2020. Yet, no impact was felt.”

This is because manual removal of Salvinia alone is not enough to control the weed, Lum says. Any plant left in the water will rapidly grow to replenish what has been stripped away.

The second option is chemical control, which involves the application of herbicides to kill the weed. But this comes with its own ecological drawbacks, as the herbicides pose a risk to other plants and could harm the lake’s other organisms. So far, the chemical approach has not been tried at Lake Ossa, and scientists including Fontem caution against trying it.

But there is one final option that could relieve Lake Ossa of Salvinia and restore its ecosystem: a small, brown-black water beetle native to Brazil known as the Salvinia weevil, which feeds almost exclusively on the weed. Measuring just 2-3.5mm long in its adult form, this tiny insect is equipped with a long, sturdy snout. But it is the weevil larvae that are devastating to the Salvinia by burrowing into the plant’s rootstalks and causing fatal damage.Removing Salivinia by hand is very labour intensive, but so far it is the only method that has been attempted at Lake Ossa (Credit: AMMCO)

Removing Salivinia by hand is very labour intensive, but so far it is the only method that has been attempted at Lake Ossa (Credit: AMMCO)

The Salvinia weevil was discovered by Wendy Forno, a scientist at Australia’s government research agency CSIRO, while carrying out surveys in South America between 1978 and 1982. The first releases of the weevil as a biological agent to destroy Salvinia were at Lake Moondarra, Mount Isa, Australia in 1980, with remarkable success.   

“Lake Moondarra is mostly clear of Salvinia today. Fifty thousand tonnes of Salvinia on the lake was killed by weevils over a 400-hectare (1.5-sq-mile) infestation,” says Matthew Purcell, director of the Australian Biological Control Laboratory, a facility run by the United States Department of Agriculture and CSIRO.

“The weevil – both adults and larvae – only feeds on this fern and not on other aquatic plants,” says Purcell. “As the plants increase seasonally, so do the weevils. The weevils [and] Salvinia constantly increase and decrease through the seasons in balance.” The weevils never fully eradicate the weed, but help to “return the system to a balance”, says Purcell.  

The weevil was also deployed in the Senegal River in the early 2000s, where it had similar success, says Arnold Pieterse, formerly a senior staff member of the Netherlands’ Royal Tropical Institute, now retired. He, too, underlines that the weevils’ strong preference for Salvinia as a food crop makes it an appealing choice for Salvinia control. “It has irrefutably been proven that the insects do not form any danger to the environment or crops,” says Pieterse.

South Africa, too, has successfully brought Salvinia molesta under control thanks to the release of the weevil into its fresh water systems since 1985. “South Africa had a number of systems infested with the weed throughout the country, mainly smaller impoundments and rivers,” says Julie Coetzee, deputy director and manager of the Aquatic Weed Biocontrol Programme at Rhodes University, South Africa. These waters took between one to three years to clear, depending on the nutrients in the water, and the climate. “We still do have some infestations appearing,” Coetzee says, but “once weevils have been released, we typically get clearing with a season”.The Salvinia weevil was first tried as a method to control the weed in Australia, where it has also invaded rivers and lakes (Credit: Getty Images)

The Salvinia weevil was first tried as a method to control the weed in Australia, where it has also invaded rivers and lakes (Credit: Getty Images)

Though the Salvinia has no defence against the weevil, the weevils themselves have weaknesses. “No drawbacks were experienced initially but nowadays, we have noticed that there are sites where infestations have persisted, particularly in shaded sites,” says Coetzee. “We have also discovered a parasitic alga infecting [the weevil] population.” This alga, called Helicosporidium, reduces the weevil’s ability to reproduce.

Nevertheless, Coetzee is optimistic that weevils could clear Cameroon’s Lake Ossa of Salvinia. “Implementing a biological control programme in Cameroon is the most ecologically friendly, economically sustainable option for control of Salvinia,” she says. “Given the size of the infestation on the lake, it is going to take a while for the control agent populations to build up to sizes that will damage the plants, and cause them to sink. This is not a fast process. Patience is key.”

Purcell, too, is hopeful that the weevils could rejuvenate Lake Ossa. “The weevils should work in Cameroon. Most control is achieved within three years,” he says. “The control lasts indefinitely, much better than spraying which must be reapplied every year and every season, with negative consequences to the aquatic environment.”

It may not be much longer before Lake Ossa becomes the next Salvinia-ridden water body to welcome weevils. A task force involving several of Cameroon’s government ministries has been set up to oversee the eradication of Salvinia in the lake through the release of the weevils.

The local people of Lake Ossa, though, are frustrated at the pace of action. “Fishing is our only source of income. We are running out of patience,” says Jean Pierre Nga, a fisherman. Dora Sih, a fish seller in the business for 25 years, agrees: “Things are not moving.”

But in AMMCO and their partners’ facilities in Dizangue, the stock of weevils is steadily growing. “They will be released into the lake as soon as we receive the authorisation permit from the government,” Kamla says. “And we hope that after two or three years, we will overcome this invasive plant.”

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Parthenium hysterophorus is a destructive weed native to Central and South America that has accidentally been introduced to many regions of the world including Australia, Asia, Africa, and the Pacific Islands. The weed dramatically reduces crop yields, impacts biodiversity, causes human health issues such as respiratory difficulty and rashes, and taints valuable livestock milk. Beginning in 2005, Virginia Tech’s Feed the Future Innovation Lab for Integrated Pest Management and Virginia State University initiated a classical biocontrol program to manage the weed in East Africa. Biocontrol programs have also been set up in Australia, South Africa, Pakistan, and India, with fortuitous introductions of natural enemies to Nepal. Zygogramma bicolorata – a leaf-feeding beetle – and Listronotus setosipennis – a stem-boring weevil – are the primarily natural enemies implemented in the biocontrol program, but a number of supplementary natural enemies have been introduced to Australia. The use of biocontrol to mitigate the spread of parthenium has demonstrated major success reducing the vegetative and reproductive aspects of the weed and restor-ing valuable land. This webinar will cover biocontrol of parthenium weed in both Asia and Africa, as well as how to develop a biocontrol program from start to finish, how to rear and release natural enemies, evaluation of suitable biocontrol sites, among other topics.

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University of Bristol

Animals fake death for long periods to escape predators

1-Mar-2021 10:00 AM EST, by University of Bristolfavorite_border

Newswise: Animals fake death for long periods to escape predators

Nigel R. Franks

European antlion (Euroleon nostras) on its dorsal side playing dead.

Embargoed until 00.01hrs UK time on Wednesday 3 March 2021

Newswise — Many animals feign death to try to escape their predators, with some individuals in prey species remaining motionless, if in danger, for extended lengths of time.

Charles Darwin recorded a beetle that remained stationary for 23 minutes – however the University of Bristol has documented an individual antlion larvae pretending to be dead for an astonishing 61 minutes. Of equal importance, the amount of time that an individual remains motionless is not only long but unpredictable. This means that a predator will be unable to predict when a potential prey item will move again, attract attention, and become a meal.

Predators are hungry and cannot wait indefinitely. Similarly, prey may be losing opportunities to get on with their lives if they remain motionless for too long. Thus, death-feigning might best be thought of as part of a deadly game of hide and seek in which prey might gain most by feigning death if alternative victims are readily available.

The study, published today in science journal Biology Letters, involved evaluating the benefits of death-feigning in terms of a predator visiting small populations of conspicuous prey. Researchers used computer simulations that utilise the marginal value theorem, a classical model in optimization.

Lead author of the paper Professor Nigel R. Franks from the University of Bristol’s School of Biological Sciences, said: “Imagine you are in a garden full of identical soft fruit bushes. You go to the first bush. Initially collecting and consuming fruit is fast and easy, but as you strip the bush finding more fruit gets harder and harder and more time consuming.

“At some stage, you should decide to go to another bush and begin again. You are greedy and you want to eat as many fruit as quickly as possible. The marginal value theorem would tell you how long to spend at each bush given that time will also be lost moving to the next bush.

“We use this approach to consider a small bird visiting patches of conspicuous antlion pits and show that antlion larvae that waste some of the predator’s time, by ‘playing dead’ if they are dropped, change the game significantly. In a sense, they encourage the predator to search elsewhere.”

The modelling suggests that antlion larvae would not gain significantly if they remained motionless for even longer than they actually do. This suggests that in this arms race between predators and prey, death-feigning has been prolonged to such an extent that it can hardly be bettered.

Professor Franks added: “Thus, playing dead is rather like a conjuring trick. Magicians distract an audience from seeing their sleights of hand by encouraging them to look elsewhere. Just so with the antlion larvae playing dead – the predator looks elsewhere. Playing dead seems to be a very good way to stay alive.”

Paper:

‘Hide-and-seek strategies and post-contact immobility’ by NR Franks, A Worley and AB Sendova-Franks in Biology Letters

Image:

European antlion (Euroleon nostras) on its dorsal side playing dead. Credit: Nigel R. Franks

https://fluff.bris.ac.uk/fluff/u1/hu21584/gouW2eLlMqxEzBsRwNZxGAzcJ/

Issued on Monday 1 March 2021 by University of Bristol Media and PR Team. For more information email press-office@bristol.ac.uk.

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Bug wars: Feds introduce Asian wasps to battle emerald ash borer outbreak in Lincoln area

Ash borer wasps

The Tetrastichus planipennisi wasp lays eggs in the larvae of the emerald ash borer.

  • Peter Salter

A piece of ash branch, infested with the emerald ash borer and injected with the eggs of the Tetrastichus planipennisi wasp, was attached to an ash tree at Platte River State Park last summer.

City tree crews discovered the first signs of emerald ash borer infestation in a tree near 37th and F streets.

One of the newest members of Lincoln’s insect family is a little wasp with a big name and no desire for human flesh.

But it can’t live without the emerald ash borer.

The Tetrastichus planipennisi is an underhanded killer, penetrating the bark of an infected ash tree with its ovipositor — the stinger on other species — to lay eggs in the larvae of the emerald ash borer.

“Then the eggs hatch,” said Dave Olson, a forest health specialist with the Nebraska Forest Service. “And they eat the ash borer from the inside-out.”

Its cousin, Oobius agrili, likes its borers even younger: It injects its own egg inside an ash borer egg, eventually hatching, growing and killing its host.

In both cases, the parasitic wasps mature — larvae, pupae, adulthood — then fly away, looking for more victims, continuing the cycle.

 Ash borer update: Some trees to get reprieve; replanting plans not taking root everywhere

And the brutality of this bug-eat-bug world is now being waged in Lincoln and nearby state parks, introduced to the area by the U.S. Department of Agriculture in an attempt to slow the spread of the emerald ash borer.

The Asian beetle, about the size of a cooked grain of rice, was first confirmed in North America in the early 2000s and has been eating its way west across the U.S. since, piling up massive damage.ADVERTISING

The insect had already killed tens of millions of ash trees — with an estimated value of $11 million — by the time it reached Nebraska, first confirmed in a Douglas County tree in 2016. It landed in Lancaster County in 2018, caught in a trap near Pioneers Park, and was discovered infesting trees in Lincoln last spring.

It’s a lethal little bug, and Lincoln’s estimated 65,000 public and private ash trees are vulnerable. The city has already started removing and replacing most of its 14,000 trees from parks, golf courses and along streets, and will attempt to prolong the lives of some with chemical treatments.

 Emerald ash borer found in Nebraska’s Saunders County

The stingless wasps were the federal government’s idea. The USDA’s Plant Protection and Quarantine program approached the state last year, and the Forest Service identified a handful of spots that could benefit from biocontrol: Pioneers Park, Mahoney and Platte River state parks and Fremont Lakes State Recreation Area.

A federal rearing lab in Michigan supplied nearly 20,000 wasps from three species and in various stages — Oobius agrili pupae, Tetrastichus planipennisi eggs, larvae and pupae, and Spathius galinae wasps.

In some cases, the lab delivers a Trojan tree limb — a branch cutting already infested with ash borer and injected with wasp larvae. Once in the field, the branch is attached to a tree that shows signs of the ash borer, and the adult wasps emerge from the cutting and start hunting in the host tree.

It’s too soon to see results, Shayne Galford, the USDA’s state plant health director for Nebraska and Kansas, said in an email. But officials will return to the release sites to introduce more wasps this year, and check for established populations in 2021. They could also add more sites, he said.

 ‘Each table is a small victory’ — How volunteers and salvage lumber are helping flood victims

The new weapon in the war on emerald ash borers won’t stop their spread, said Olson, with the state forest service. But it could crimp it.

“It’s not going to be a silver bullet. The real goal is to get these predators set up so in a few years the emerald ash borer has additional pressure on it.”

 In war against ash borer, a side skirmish erupts in east Lincoln

Reach the writer at 402-473-7254 or psalter@journalstar.com.

On Twitter @LJSPeterSalter View Comments84215

How to get ready for the emerald ash borer in the Lincoln area

Local

How to get ready for the emerald ash borer in the Lincoln area

  • Updated Feb 18, 2020

They found the first bug in August, in a treetop trap they set northwest of Pioneers Park.

Platte River floodwaters claim Rod and Gun Club cabin near Fremont
Annual Polar Plunge not so polar this time around

l

Penny

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Science

Watch how battles with bats give moths their flashy tails

Bats and their prey are in a constant arms race. Whereas the winged mammals home in on insects with frighteningly accurate sonar, some of their prey—such as the tiger moth—fight back with sonar clicks and even jamming signals. Now, in a series of bat-moth skirmishes (above), scientists have shown how other moths create an “acoustic illusion,” with long wing-tails that fool bats into striking the wrong place. The finding helps explain why some moths have such showy tails, and it may also provide inspiration for drones of the future.

Moth tails vary from species to species: Some have big lobes at the bottom of the hindwing instead of a distinctive tail; others have just a short protrusion. Still others have long tails that are thin strands with twisted cuplike ends. In 2015, sensory ecologist Jesse Barber of Boise State University in Idaho and colleagues discovered that some silk moths use their tails to confuse bat predators. Now, graduate student Juliette Rubin has shown just what makes the tails such effective deterrents.

Working with three species of silk moths—luna, African moon, and polyphemus—Rubin shortened or cut off some of their hindwings and glued longer or differently shaped tails to others. She then tied the moths to a string hanging from the top of a large cage and released a big brown bat (Eptesicus fuscus) inside. She used high-speed cameras and microphones to record the ensuing fight.

Moths with no tails (such as polyphemus) were easy quarry for the bats, escaping only about 27% of the time, Rubin, Barber, and colleagues report today in Science Advances. But when Rubin enlarged the polyphemus hindwing lobe, twice as many escaped the bat’s sonar, or echolocation system.

Bats going after long-tailed African moon moths got a mouthful of tail 75% of the time as the moths flitted away. Shorten the tail, and the African moon moths escaped only 45% of the time. With no tail at all, that percentage dropped to 34%. When Rubin’s colleagues Chris Hamilton and Akito Kawahara at the Florida Museum of Natural History in Gainesville built a family tree of silk moths and their relatives, they realized that long tails had evolved independently several times. That’s further evidence that they are an important life-saving feature for these moths.

“The authors have demonstrated a powerful approach for understanding the diversity of moth shapes,” says Aaron Corcoran, an animal ecologist at Wake Forest University in Winston-Salem, North Carolina, who was not involved with the work. “There appear to be many different ways to trick a bat’s echolocation system.” The study also revealed how hard it was for bats to work around this deception, he adds. “The fact that the bats in the study never learned how to catch these moths, despite ample time to do so, shows how hard-wired this blind spot is in the bat’s perception.”

The findings could benefit other fields such as robotics, says Martin How, a sensory ecologist at the University of Bristol in the United Kingdom. Because the study examined the bat-moth dogfights at such a fine scale, the results could help engineers design the “bio-inspired technologies of the future,” he says, including deftly flying drones.

*Correction, 5 July, 1:45 p.m.: This article has been updated to reflect that although Juliette Rubin was the lead author of the paper, some of the work was done by other researchers.

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moroccoworldnews-logo-top

Morocco to Provide Biofriendly Pest Control

By Hajare El Khaldi

Rabat- The biological pest control group, Biobest, announced the launch of its new, EUR 1.2 million “state-of-the-art” facility, which will boost Morocco’s aphid biocontrol capacity, on April 24.

Aiming to satisfy the strong demand for zero-residue products and tackle the rising problem of pesticide resistance, the Belgium-based company fully equipped the 2,000 square-meter vertical livestock facility with air-conditioned rooms, thus preparing to ensure a “flexible” and “reliable” supply to its customers.

“Aphids remain one of the most challenging pests to control with biological methods,” declared Biobest, which offers producers around the world a full range of “natural enemies” for agricultural pest problems, as well as the necessary technical advice for a successful pests control.

While synthetic chemical pesticides are effective in protecting crops, they have proven to cause acute and chronic health effects, in addition to upsetting the natural equilibrium of agricultural systems and the environment.

Biobest provides an alternative solution that uses microbial biopesticides to work against certain pests without harming other organisms.

“The success of biocontrol against aphids does not depend on a miracle product, we recommend strategies that combine different aids in an effective way,” says Biobest sales manager, Marc Mertens, “the midge Aphidoletes has an important role to play, given its great predatory ability, since its effectively gets rid of emerging aphid infestations. It forms a powerful tandem with different parasitoid wasp species. We continue to work in expanding our range of solutions, and our consultants know how to help producers best combine the most effective IPM solutions in different crops and climates.”

This project is expected to reinforce the company’s position as a leading supplier for integrated pest management solutions in Morocco and to underline the Moroccan franchise’s role within the global production network, asserted the managing director of Biobest Morocco, Karim Jerate.

Founded in 1987, Biobest offers biofriendly solutions to producers in more than 60 countries, Through its subsidiaries, the company has productions sites, sales personnel, and technical support strategically located around the world for efficient global service.

“With several production sites around the globe, our goal is to offer a flexible response capability to producers in different parts of the world. Our Moroccan team has done a remarkable job completing the construction of this new production plant on time and according to the required specifications,” said Biobest Chief Operating Officer, Karel Blockmans.

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Science

How one parasitic wasp becomes the victim—of another parasitic wasp

Karma is a real pest for parasitoids, tiny parasitic wasps that lay their eggs on caterpillars. That’s because the way they protect their hungry young from the caterpillar’s immune system sends out a chemical calling card that lures other parasites, which feast on the offspring, according to a new study.

For the parasitoid’s brood, a caterpillar is a walking nursery and buffet. But that brood is on the menu for wasps called hyperparasitoids, which lay their eggs on the parasitoid offspring. Researchers previously found that hyperparasitoids sniff out their victims using the distinctive aroma a plant emits when being munched by a parasitized caterpillar.

What’s ultimately responsible for the release of this odor, scientists report today in the Proceedings of the National Academy of Sciences, is a virus that parasitoids squirt into a caterpillar to suppress its immune system and shield their offspring. When the researchers injected caterpillars with the virus and let the insects gnaw on wild cabbage plants, they found that the scent of the plants was particularly attractive to the hyperparasitoid Lysibia nana (above, laying its eggs on the parasitoid’s cocoons). The study suggests the virus changes the chemical composition of the caterpillars’ saliva, which in turn causes the plant to release molecules that are wasp-nip for hyperparasitoids.

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Cornell University

Cornell Chronicle

Graduate student Ricardo Perez-Alvarez checks cabbage plants for insect pests.

Landscapes surrounding farms affect insect pests, crop yields, study finds

A cabbage looper, a pest of cabbage plants.

Landscapes that surround agricultural lands strongly influence the dynamics of beneficial insects as well as insect pests on farms, which in turn affect crop yields.

Such were the findings of a Cornell study of New York farmlands, published April 4 in the journal Ecological Applications.

Many previous studies on how landscapes surrounding farms affect insect pests and crops have only considered one pest at a time. This study examined the effects of three cabbage pests – aphids, flea beetles and leaf-feeding caterpillars – wasps that feed on caterpillars, and crop yields. It also looked at three different types of landscapes that surround farms: agricultural lands, meadows and semi-natural areas (including shrublands, types of forests and woody wetlands).

“By considering multiple insect pests, [our study design] represented a more realistic situation for what farmers experience, we were able to disentangle some of these complexities,” said Ricardo Perez-Alvarez, the paper’s first author and a graduate student in the lab of Katja Poveda, professor of entomology and the paper’s senior author.

In the study, the researchers set up 22 experimental cabbage plots on farms across the Finger Lakes region of New York from June to September in 2014 and 2015. The details and management of each plot were the same, with no pesticides or insecticides used. Throughout the growing season, the researchers measured plant damage by each pest, density and abundance of parasitoid wasps, and they recorded crop yields at the end of each season.

The researchers expected that landscapes with a higher proportion of cropland and lower habitat diversity would lead to more specialist pests and a reduction in crop yields, according to the paper. Instead, they found that yields and the number of pests were best explained by the presence of non-crop habitats, such as meadows, in the landscape.

Specifically, when the proportion of meadows surrounding farms was high, the amount of infestation from cabbage leaf-eating caterpillars was lower, likely because of increased parasitism from wasps. On the other hand, these same plots experienced more infestation from flea beetles and aphids. The findings suggest that while some beneficial insects increased as a result of the non-crop habitats, so did the number of certain pests.

By considering the collective effect of multiple pest species on crop yields, management schemes need to consider joint effects of pest species to be effective, Perez-Alvarez said. Still, more detailed study is needed to better understand these dynamics. “There were some landscapes where the presence of meadows can have an overall positive effect from crop production, but in other areas, meadows can have a negative effect,” he said, perhaps due to the characteristics of the insect fauna that live in those areas.

“There is not a universal solution,” he added.

Brian Nault, professor of entomology, is a co-author of the study.

The study was supported by U.S. Department of Agriculture’s National Institute of Food and Agriculture via the Cornell University Agricultural Experiment Station.


Story Contacts

Krishna Ramanujan

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Ghana News Agency

http://www.ghananewsagency.org/science/ghana-to-focus-on-bio-rational-products-for-management-of-faw-131321

fall-armyworm-frontal-MER-563x744

Ghana to focus on bio-rational products for management of FAW

By Belinda Ayamgha, GNA

Accra, April 13, GNA – The Ministry of Food and Agriculture says it has shifted its focus from synthetic insecticides to bio-rational products, for the management of the Fall Armyworm (FAW) infestation, as part of its short, medium and long-term management measures.

The focus on bio-rational products is to ensure minimum pest resistance by the FAW, which is higher with the use of synthetic insecticides.

Dr Mrs Felicia Ansah, Director of Plant Protection and Regulatory Services at MoFA, said this when she briefed Journalists on the current situation of the FAW problem.

She noted that the FAW had come to stay, as it could not be completely eradicated but managed, as in the case of Brazil, which had been managing the FAW infestation for the past 40 years, and was currently one of the biggest exporters of maize.

Ghana had thus modelled its management measures after the Brazilian experience.

These measures, she said, include the deployment of pheromone trap catches in various locations across the country to ascertain the levels of infestation, training of MoFA staff and farmers on scouting, early detection and sustainable management of the pest in the event of an outbreak.

She explained that the best way to manage the infestation on farms was to detect the pests early at the larvae stage, and not when they became full grown moths. That is when they did the most damage to crops.

Other measures being undertaken by the Ministry are the distribution of pesticides to all district offices in the country where farmers can access in FAW infestations, the formation and training of Nnoboa Spraying Teams in farming communities and intensification of public awareness creation for farmers and the general public.

According to Dr Ansah, Ghana had commenced scouting of natural enemies of the FAW, which once identified, will be reared to help reduce the population of the pests.

“In the long term, only biological control agents, microbial insecticides and botanicals/organic products will be used to manage FAW in Ghana,” she said.

She said a total of 249,054 hectares of maize were affected and sprayed, out of which 234,807 hectares recovered and 14, 247 totally destroyed in the previous season, adding that there was a likelihood for more infestations in the 2018 farming season.

Dr Ansah stressed the need for the media to be circumspect in how they reported issues around the FAW infestation as it had implications for trade.

She urged the media to collaborate with the Ministry to educate farmers on how to manage the FAW.

She said the pockets of FAW infestations being currently experienced in some districts in the Ashanti, Brong-Ahafo, Eastern, Volta and Western Regions had been blown out of proportion as it was a pre-season production infestation.

“We would like you to appreciate that this is a Phytosanitary or Public Plant Health Issue, with trade implications and must be communicated in a professional manner. Media coverage should rather be geared towards improving the knowledge and skills of our farmers,” she said.

GNA

 

 

 

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