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New rice IPM book

To see video go to:

https://shop.bdspublishing.com/checkout/Store/bds/Detail/WorkGroup/3-190-9781786761965

Rice_pests_aRice_pests_b

 

  • International Conference on Emerging Trends in Integrated Pest Management for Quality Food Production
  • 25-27 July 2017
  • The Waterfront Hotel, Kuching, Malaysia

To register go  to:

https://www.cvent.com/events/international-conference-on-emerging-trends-in-integrated-pest-and-disease-management-for-quality-fo/registration-3a4013628d8947bdbd69c34bc96f2a35.aspx?fqp=true

 

Fall Armyworm Life Cycle

The Life Cycle of Fall Armyworm

1d ago

Fall armyworm life cycleThe Fall armyworm, Spodoptera frugiperda, is a major invasive pest in Africa. It has a voracious appetite and feeds on more than 80 plant species, including maize, rice, sorghum and sugarcane. Another feature which makes it an incredibly successful invasive species is its ability to spread and reproduce quickly. CABI have developed a poster to show the life cycle of the Fall armyworm, which includes egg, 6 growth stages of caterpillar development (instars), pupa and adult moth. Click here to view the full poster, or read about the life cycle below.

Day 1-3
100-200 eggs are generally laid on the underside of the leaves typically near the base of the plant, close to the junction of the leaf and the stem. These are covered in protective scales rubbed off from the moths abdomen after laying. When populations are high, the eggs may be laid higher up the plants or on nearby vegetation.

Day 3-6
Growth stages 1-3: After hatching, the young caterpillars feed superficially, usually on the undersides of leaves. Feeding results in semitransparent patches, or “windows”, on the leaves. Young caterpillars can spin silken threads which catch the wind and transport the caterpillars to a new plant. The leaf whorl is preferred in young plants, whereas the leaves around the cob silks are attractive in older plants. If the plant has already developed cobs then the caterpillar will eat its way through the protective leaf bracts into the side of the cob where it begins to feed on the developing kernels. Feeding is more active during the night.

Day 6-14
Growth stages 4-6: By stages 4-6, the fall armyworm will have reached the protective region of the whorl, where it does the most damage, resulting in ragged holes in the leaves. Feeding on young plants can kill the growing point, resulting in no new leaves or cobs. Often only 1 or 2 caterpillars found in each whorl, as they become cannibalistic when larger and will eat each other to reduce competition for food. Large quantities of frass (caterpillar poo) , which resembles sawdust, will be present.

Day 14-23
After approximately 14 days the fully grown caterpillar will drop to the ground. The caterpillar will then burrow 2-8 cm into the soil before pupating. The loose silk oval shape cocoon is 20-30 mm in length. If the soil is too hard then the caterpillar will cover itself in leaf debris before pupating. After approximately 8-9 days the adult moth emerges to restart the cycle.

This information has been adapted from ‘Fall Armyworm: Life cycle and damage to Maize’
To read more about what CABI is doing to help control Fall Armyworm in sub-Saharan Africa, please visit www.cabi.org/fallarmyworm

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  1. Reblogged this on The Invasives Blog.

 

 

LSU AgCenter weed scientist Daniel Stephenson holds a ragweed parthenium plant Photo by Olivia McClure/LSU AgCenter
LSU AgCenter weed scientist Daniel Stephenson holds a ragweed parthenium plant at the annual field day at the Dean Lee Research and Extension Center in Alexandria on July 13, 2017.

False ragweed becoming major row-crop pest in Louisiana

Ragweed parthenium (also know as false ragweed) has gone from a nuisance in pastures to a major pest in Louisiana row crops.

Bruce Schultz 1, Olivia McClure | Jul 18, 2017

An LSU AgCenter weed scientist speaking at a field day on July 13 at the Dean Lee Research and Extension Center warned farmers about ragweed infestations in their fields.

The scientist, Daniel Stephenson, said ragweed parthenium has gone from a nuisance in pastures to a major pest in Louisiana row crops. Ragweed parthenium is also known as false ragweed.

 The weed can become a major problem quickly if it is not controlled early. Ragweed parthenium often germinates after spring burndown herbicide applications and is not discovered until after crops have emerged, Stephenson said.

Applications of certain herbicides prior to or at planting can provide control of an existing population, he said.

Current research shows that after crop emergence, control options are limited, but Stephenson recommended sequential applications of either Liberty, Liberty plus Roundup PowerMax, or Roundup PowerMax plus a half pound per acre of dicamba.

Stephenson said it’s likely the weed has been spread by equipment.“Ragweed parthenium is a very troublesome weed that is difficult to control with herbicides,” he said. “If a producer sees it in their field, they need to remove it.”

The fruit fly brain

Science/AAAS

Examples of eight fruit fly brains with regions highlighted that are significantly correlated with (clockwise from top left) walking, stopping, increased jumping, increased female chasing, increased wing angle, increased wing grooming, increased wing extension, and backing up.

Kristin Branson

Artificial intelligence helps scientists map behavior in the fruit fly brain

Can you imagine watching 20,000 videos, 16 minutes apiece, of fruit flies walking, grooming, and chasing mates? Fortunately, you don’t have to, because scientists have designed a computer program that can do it faster. Aided by artificial intelligence, researchers have made 100 billion annotations of behavior from 400,000 flies to create a collection of maps linking fly mannerisms to their corresponding brain regions.

Experts say the work is a significant step toward understanding how both simple and complex behaviors can be tied to specific circuits in the brain. “The scale of the study is unprecedented,” says Thomas Serre, a computer vision expert and computational neuroscientist at Brown University. “This is going to be a huge and valuable tool for the community,” adds Bing Zhang, a fly neurobiologist at the University of Missouri in Columbia. “I am sure that follow-up studies will show this is a gold mine.”

At a mere 100,000 neurons—compared with our 86 billion—the small size of the fly brain makes it a good place to pick apart the inner workings of neurobiology. Yet scientists are still far from being able to understand a fly’s every move.

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To conduct the new research, computer scientist Kristin Branson of the Howard Hughes Medical Institute in Ashburn, Virginia, and colleagues acquired 2204 different genetically modified fruit fly strains (Drosophila melanogaster). Each enables the researchers to control different, but sometimes overlapping, subsets of the brain by simply raising the temperature to activate the neurons.

Then it was off to the Fly Bowl, a shallowly sloped, enclosed arena with a camera positioned directly overhead. The team placed groups of 10 male and 10 female flies inside at a time and captured 30,000 frames of video per 16-minute session. A computer program then tracked the coordinates and wing movements of each fly in the dish. The team did this about eight times for each of the strains, recording more than 20,000 videos. “That would be 225 straight days of flies walking around the dish if you watched them all,” Branson says.

Next, the team picked 14 easily recognizable behaviors to study, such as walking backward, touching, or attempting to mate with other flies. This required a researcher to manually label about 9000 frames of footage for each action, which was used to train a machine-learning computer program to recognize and label these behaviors on its own. Then the scientists derived 203 statistics describing the behaviors in the collected data, such as how often the flies walked and their average speed. Thanks to the computer vision, they detected differences between the strains too subtle for the human eye to accurately describe, such as when the flies increased their walking pace by a mere 5% or less.

“When we started this study we had no idea how often we would see behavioral differences,” between the different fly strains, Branson says. Yet it turns out that almost every strain—98% in all—had a significant difference in at least one of the behavior statistics measured. And there were plenty of oddballs: Some superjumpy flies hopped 100 times more often than normal; some males chased other flies 20 times more often than others; and some flies practically never stopped moving, whereas a few couch potatoes barely budged.

Then came the mapping. The scientists divided the fly brain into a novel set of 7065 tiny regions and linked them to the behaviors they had observed. The end product, called the Browsable Atlas of Behavior-Anatomy Maps, shows that some common behaviors, such as walking, are broadly correlated with neural circuits all over the brain, the team reports today in Cell. On the other hand, behaviors that are observed much less frequently, such as female flies chasing males, can be pinpointed to tiny regions of the brain, although this study didn’t prove that any of these regions were absolutely necessary for those behaviors. “We also learned that you can upload an unlimited number of videos on YouTube,” Branson says, noting that clips of all 20,000 videos are available online.

Branson hopes the resource will serve as a launching pad for other neurobiologists seeking to manipulate part of the brain or study a specific behavior. For instance, not much is known about female aggression in fruit flies, and the new maps gives leads for which brain regions might be driving these actions.

Because the genetically modified strains are specific to flies, Serre doesn’t think the results will be immediately applicable to other species, such as mice, but he still views this as a watershed moment for getting researchers excited about using computer vision in neuroscience. “I am usually more tempered in my public comments, but here I was very impressed,” he says.

Science/AAAS

Nephila-pilipes-on-a-web-2_16x9

Scientists uncover trick to spider’s stealth

You almost never notice a spider descend from the ceiling until it’s right in front of you. Coming down on its silk thread—the dragline—it barely moves or spins. Now, scientists have figured out why. In a study published this month in Applied Physics Letters researchers collected some golden silk orb-weaver spiders (Nephila edulis and N. pilipes, the latter pictured), raised them in the lab, and collected their dragline silk. They used a device that can measure extremely small forces—the torsion pendulum, the same apparatus that Henry Cavendish used to estimate Earth’s mass about 200 years ago—now equipped with image processing capability. All the other fibers they tested—including human hair, metal wires, and carbon fiber—behaved like an elastic material when twisted, just like a rubber band that comes back to its original shape when twisted or stretched. But, the dragline silk underwent permanent molecular deformation upon twisting. This warping rapidly slows down any movements, steadying the spider. The unique arrangement of molecules in dragline silk—rigid structures that help maintain its overall shape, and soft structures that act like a cushion, absorbing any motion—is responsible for this behavior, the authors suspect. The findings could lead to ropes for rescue helicopter ladders or rappelling climbers that don’t throw us into a spin.

Insecticides being sprayed on coffee plants in Uganda, a country with endemic schistosomiasis. 

REUTERS/Hereward Holland

Pesticides could hike risk of catching a parasitic worm

Pesticides are a double-edged sword: They make farming more productive, but they can harm wildlife and people if not used properly. Now, ecologists have identified a new threat from pesticides in the developing world. By killing off insect predators of worm-infested snails, they can raise the risk of schistosomiasis, the second most common parasitic disease after malaria.

“It’s a ground-breaking article,” says Russell Stothard, a parasitologist at the Liverpool School of Tropical Medicine in the United Kingdom, who was not involved in the research.

Schistosomiasis is a debilitating disease caused by a parasitic flatworm. Some 258 million people are infected, mostly in Africa. The worm spends part of its life in freshwater snails, which release larvae that can penetrate the skin of someone swimming, bathing, or washing clothes. The centimeter-long worms spread through blood vessels, causing fever, diarrhea, anemia, and stunted growth. Immune responses can damage the kidneys and other organs. When infected people relive themselves, the worms’ eggs can spread into streams or ponds via their urine and feces. There, they hatch and seek out new snails, beginning their life cycle again. Schistosomiasis can easily be treated with drugs, but where the parasites are endemic, people quickly become reinfected.

The leader of the new research, ecologist Jason Rohr of the University of South Florida in Tampa, had previously studied a similar parasitic flatworm in amphibians. His research showed that common agricultural chemicals, like fertilizer, can worsen the situation for frogs. When these chemicals enter streams and ponds, they increase the amount of algae, which is then eaten by snails that serve as a host for the flatworms. That boosts their population and leads to more parasite infections in frogs.

The similar life cycles of the amphibian flatworm and the one that causes schistosomiasis made Rohr and his colleagues wonder whether agricultural pollution might also affect disease transmission. They created a simple ecological model inside 60 open tanks. After filling each with 800 liters of pond water, they added two species of snails that spread the schistosomiasis parasite, algae for the snails to eat, and two kinds of predators—crayfish and water bugs. Finally, they spiked the tanks with three kinds of farm chemicals—fertilizer, herbicide, and insecticide—in various combinations. The concentrations were typical of streams and ponds near corn fields in the United States.

As expected, fertilizer increased the amount of algae in the tanks, which in turn swelled the number of snails. The herbicide also led to more food for the snails, because it predominately killed microscopic algae that clouded the water. When these died, the water cleared, allowing more light to reach larger algae growing on the bottom of the pond—the snails’ food. An epidemiological model of schistosomiasis suggested that the increase in snail population from this typical amount of fertilizer would jack up the risk of transmission to humans by 28%.

The insecticide, chlorpyrifos, had an even bigger effect by killing the two predators of the snails. Water bugs stick their heads inside the shell, bite the mollusc, inject digestive enzymes, then slurp up the remains. The 20-centimeter-long crayfish rely on brute force, crushing the 2-centimeter-long snails. “They’re absolutely voracious,” Rohr says. With these predators gone, the snail population exploded. In such a scenario, disease risk to humans would rise 10-fold, the team reports in a preprint posted this week to bioRxiv. Although only one concentration of insecticide was added to the tanks, the model indicated that lower concentrations in ponds would still have substantial impacts on parasite transmission.

The findings identify what looks like a “strong risk factor” for schistosomiasis, says Joanne Webster, a parasitologist at Imperial College London who was not involved.

Dams have also caused an increase in schistosomiasis in many countries, because snails live in the reservoirs and irrigation channels. In some places, dams have also caused a decline in the natural predators of snails, such as fish, crayfish, and prawns. The combination of new habitat from irrigation and runoff of pesticides may be a “perfect storm” for schistosomiasis where agriculture is intensifying in the developing world, Rohr says.

Rohr is now investigating the impact of insecticides on snail predators and disease transmission in northwest Senegal, as part of an experiment run by a research partnership called the Upstream Alliance, based in Pacific Grove, California. This project has reintroduced prawns near several villages to evaluate their efficacy in controlling freshwater snails. Rohr will study whether helping farmers switch to insecticides less toxic to prawns could lessen the burden of schistosomiasis, while maintaining food production. “In schistosomiasis-endemic regions, we need to think more carefully about the impact of agrochemicals,” he says.

The study highlights the complex links between agriculture and disease, says Charles Godfray, a biologist at the University of Oxford in the United Kingdom. By boosting agricultural productivity, pesticides and other chemicals can help raise people out of poverty and lessen malnutrition, which worsens diseases. “The really clear thing is the importance of precision agriculture, in which agrochemicals are used as efficiently as possible, with as little runoff as possible.”