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Deutsche Welle

Eco@Africa

Working with insects in Africa

The International Centre of Insect Physiology and Ecology in Kenya was founded in 1970 and aims to improve the lives and health of people in tropical Africa by focusing on harmful and useful arthropods.

We recently met with Dr. Sunday Ekesi from the center to discus their sustainability push throughout tropical Africa. The institute’s work is modeled around integrating human, animal, plant and environmental health issues. Its mission is to “help alleviate poverty, ensure food security and improve the overall health status of peoples of the tropics, by developing and extending management tools and strategies for harmful and useful arthropods.”

DW: How can insects benefit people?

Sunday Ekesi: There are certain insects that are parasitic and live on invasive ones. And by bringing in some of the parasitic ones that attack the bad ones — that is one very important aspect of what we call classical biological control to bring an insect that is damaging to a very minimal level by reuniting the good and the bad one in the environment so that the population is kept at the very very minimal level without harming our crops or without harming our livestock. Insects contribute in all these ways to help improve our economy.

DW eco@africa - Dr. Sunday Ekesi (DW)

Dr. Sunday Ekesi from Kenya’s International Centre of Insect Physiology and Ecology

 

Everybody knows that insects damage crops. In Africa is that on the increase or on the decrease?

That’s a very important question because the recent invasion of the fall armyworm on the continent gives you an indication that there is an increasing trend in terms of invasions of insects into the continent. Africa is not an exception. Invasions happen globally.

We are working with various governments and various institutions and donor agencies to help us address this.

But in order to minimize this there should be a need for a lot of involvement at the national level and private sectors so that we pick issues related to preparedness, contingency planning, best risk analysis and predictive modeling to be able to know that there are certain insects that are of danger to us and to begin to guard against such invasions. Because when you are taken unaware we begin to run helter-skelter. But if we are well prepared the chances are that the impact that this will have on the environment and the food security situation at large won’t be as severe as what we’re seeing now.

Take me through a specific example.

Tuta absoluta is believed to be native to Latin America and it first invaded Europe — I believe Spain — and it began to spread in Europe. From Europe it got into North Africa. Tunisia, Morocco and Sudan were all invaded and then it began to spread into sub-Saharan Africa up to southern Africa. What most probably happened is difficult to say exactly. But the most likely thing is the movement of produce around borders without proper quarantine or sanitary management facilities led to its easy movement.

Here it does not have its natural enemies, so it tends to explode. So we went to Peru to carry out an exploration for a natural enemy given that Latin America is believed to be the origin of this pest. Once you have the natural enemy the population begins to stabilize. So we embarked on that and we are beginning to work with national governments to release these parasites across Africa.

In addition to that we looked at a sustainable management measure that is based on a combination of control measures. Because if you rely too much on pesticides the tendency is that there are other beneficial organisms in addition to the one that we brought in that are supposed to keep the pest in check so that it does not grow to economic injury level. So we are looking at the possibility of introducing softer options such as the use of pesticides, the use of attractants, the use of traps and the use of intercropping the natural weeds. But if you apply too much pesticide, you kill the beneficiaries and the problem remains.

How has global warming impacted insect populations?

Because the temperature is warming, there is the tendency for insects to begin to move from warm areas to cool areas which changes distribution patterns. So climate change is also changing the context in terms of natural enemies — the interaction between the bad and the good ones.

This interview has been shortened and edited for clarity.

 

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T. S. Park et al./Nature Communications, 10.1038

This ancestor of today’s insects, spiders, and crustaceans had a simple brain, but complex eyes

Although it’s hard to believe that delicate nervous tissues could persist for hundreds of millions of years, that’s exactly what happened to the brains and eyes of some 15 ancestors of modern-day spiders and lobsters, called Kerygmachela kierkegaardi (after the famous philosopher Søren Kierkegaard). Found along the coast of north Greenland, the 518-million-year-old fossils contained enough preserved brains and eyes to help researchers write a brand-new history of the arthropod nervous system.

Until now, many biologists had argued that ancient arthropods—which gave rise to today’s insects, spiders, and crustaceans—had a three-part brain and very simple eyes. Compound eyes, in which the “eye” is really a cluster of many smaller eyes, supposedly evolved later from a pair of legs that moved into the head and was modified to sense light.

But these new fossils, which range from a few centimeters to 30 centimeters long, had a tiny, unsegmented brain, akin to what’s seen in modern velvet worms, researchers report today in Nature Communications. Despite the simple brain, Kerygmachela’s eyes were probably complex, perhaps enough to form rudimentary images. The eyes, indicated by shiny spots in the fossil’s small head, appear to be duplicated versions of the small, simple eyes seen today in soft, primitive arthropods called water bears and velvet worms.

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This legless insect can jump 30 times its body length

SAN FRANCISCO, CALIFORNIA—U.S. figure skater Nathan Chen may wow crowds with his endless quadruple jumps, but the Olympic hopeful can’t hold a candle to the legless gall midge larva (Asphondylia sp). The 3-millimeter-long larva—which startled scientists when it started hopping out of its lab dishes—plants its rear end on the ground, slides its head toward its nether regions, and latches its body into a loop, which it then flattens by shifting fluids inside its body. After enough pressure builds up, the midge releases the latch, straightens, and flies into the air at 1 meter per second for a jump as much as 30 times its body length. On a human scale, that distance would be 60 meters. (Consider: The current long jump record is less than 9 meters, with a running start.) Researchers discovered the feat with super–high-speed video cameras that shot 20,000 frames per second. The secret to the midge’s success is power amplification—the ability to build up force and then release it all at once, they report here today at the annual meeting of the Society for Integrative and Comparative Biology. It’s like an archer pulling back a bowstring, temporarily storing the energy for shooting the arrow in the elastic string. No one knows yet why the midge larva jumps—until it matures into a fly, it never leaves its home, an abnormal growth on a type of goldenrod called silverrod. But documenting its Olympian performance could help scientists understand the movements of similar larval flies—and design better robots.

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Reuters

December 6, 2017

Rats join mosquitoes as targets for ‘gene drive’ pest control

LONDON (Reuters) – Rodents have joined mosquitoes in the cross-hairs of scientists working on a next-generation genetic technology known as “gene drive” to control pests.

FILE PHOTO: A rat eats pieces of bread thrown by tourists near the Pont-Neuf bridge over the river Seine in Paris, France, August 1, 2017. REUTERS/Christian Hartmann/File Photo

Researchers in Scotland said on Tuesday they had developed two different ways to disrupt female fertility in rats and mice, building on a similar approach that has already been tested in the lab to eliminate malaria-carrying mosquitoes.

So-called gene drives push engineered genes through multiple generations by over-riding normal biological processes, so that all offspring carry two copies. Usually, animals would receive one copy of a gene from the mother and one from the father.

The technique is extremely powerful but also controversial, since such genetically engineered organisms could have an irreversible impact on the ecosystem.

Concerns about the proliferation of mutant species have led some to call for a gene drive ban, but Bruce Whitelaw of the University of Edinburgh’s Roslin Institute believes that would be short sighted.

“A moratorium would prevent the research which is required for us to understand if and how this can be used in an advantageous way for our society,” he told reporters in London.

“We need to have an understanding of what gene drive can do and how it can be controlled so that decisions are based on knowledge rather than fear.”

A key appeal of a gene drive is its durable effect on pests, whether they are disease-carrying insects or crop-eating rodents. And since relatively small numbers of animals would need to be released initially, it is likely to be quite cheap.

It also offers a humane way to eliminate unwanted populations of sentient mammals like rats, which are typically killed with poison and traps.

Still, researchers agree more work is needed on the risks and potential unintended consequences of release of such animals.

Whitelaw and his colleagues, who published details of their rodent work in the journal Trends in Biotechnology, hope as a next step to build self-limiting gene drives that would burn out after a certain number of generations.

If their approach is successful, the gene drives could potentially be applied to help control a range of other non-insect pest species, such as rabbits, mink and cane toads.

 Currently, an older approach called “sterile insect technology” is being used in some areas to fight mosquitoes. Intrexon’s Oxitec unit has already deployed its sterile male mosquitoes, whose offspring die when young, in Brazil. But because Oxitec’s mosquitoes last only one generation, a vast number must be released to swamp their wild counterparts.

 

Existing approaches to fighting pests, particularly mosquitoes, have so far shown mixed success, with insecticide resistance increasing in many parts of the world and drugmakers struggling to develop good vaccines against complex diseases such as dengue.

Reporting by Ben Hirschler; Editing by Mark Potter

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miniaturerobots_111417

 

Mini Robots Could Cut Pesticide Use, Food Waste, and Help Harvests


UNITED KINGDOM – Could miniature robots be joining the ranks of farmhands around the globe? According to The Guardian, yes, but optimistically, not for another couple of years. Developing in laboratories now, academic farming experts are researching whether miniature robots are a solution to chemical use, food waste, and labor shortages on farms, and posit that while a possible solution, mini robots might not be the answer farmers are seeking yet.

As reported by the source, current blanket practices waste 95% to 99% of pesticides and herbicides as the method “blankets” chemicals across entire fields, allowing pests and weeds to grow resistant, harming helpful pollinators like bees, and essentially rendering the chemicals ineffective over time.
Toby Bruce, Professor of Insect Chemical Ecology, Keele University

Toby Bruce, Professor of Insect Chemical Ecology, Keele University“Farmers have been heavily reliant for decades on the heavy use of pesticides. Some spraying is very desperate,” said Toby Bruce, Professor of Insect Chemical Ecology at Keele University, according to The Guardian. “Farmers are spraying [chemicals] to which there is resistance. They will not be killing pests as the pests have evolved resistance. They will be killing other insects [such as pollinators].”
In order to reduce pesticide waste and its harmful side effects, researchers are programming the robots to be able to apply tiny quantities of pesticides directly to the plants that need them.
Robots aiding in farming a cabbage field

Robots aiding in farming a cabbage field

The robots are also able to detect when fruit and vegetables are too small or malformed to be harvested. Because malformed produce typically has a lower market value, this would help reduce food waste and allow produce enough time to be harvested when it is ready.
With labor shortages worrying farmers worldwide, the mini robots could also provide the extra hands needed to harvest crops in the field. And this isn’t the only place in our industry seeking extra help from artificial intelligence. Last month, Giant Foods stores piloted Marty, and Walmart began testing shelf-scanning robots in over fifty stores.
While robots seem to be an easy solution, The Guardian reported that the technology is not at an advanced enough stage to implement in the field just yet, and noted that start-ups are needed to spearhead this innovation as many farm technology companies are unwilling to give up their current business models.
With technology advancing every day and offering different ways to rid pests and minimize waste, are mini robots the future of sustainable farming? AndNowUKnow will continue to report on the robot takeover.

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Newsnewswise-logo-

Released: 2-Nov-2017 6:05 PM EDT

Source Newsroom: South Dakota State University

  • Under moist conditions, the Diaporthe pathogens on these soybean stems multiply.

  • South Dakota State University field crops pathologist Febina Mathew and Kristina Petrović, a visiting scientist from Serbia, examine soybeans for evidence of stem canker, focusing on the nodes or joints. Not only is this disease hard to distinguish from other soybean diseases, but the pathogen can be transmitted through the seeds.

  • Reddish brown lesions, particularly at the joint or node, are indications of soybean stem canker.

  • Kristina Petrović, a visiting scientist from Serbia, examines Diaporthe pathogens isolated from soybeans that farmers, crop consultants and soybean researchers across the United States have sent to South Dakota State University field crop pathologist Febina Mathew.

  • Newswise — Scouting soybean fields and identifying diseases are some of the tasks that Kristina Petrović performs as a research associate at the Institute of Field and Vegetable Crops in Serbia. She is expanding her work on pathogens that affect soybeans as a visiting scientist at South Dakota State University, where she is working with field crops pathologist Febina Mathew, an assistant professor in the Department of Agronomy, Horticulture and Plant Science.

“I am happy when I find disease,” Petrović quipped. She was the first to report that three species of Diaporthe, the pathogen that causes stem canker of soybean, were triggering Phomopsis seed decay in Serbia. Petrović published two papers on her findings in Plant Disease, an American Phytopathological Society journal. When she told the journal editor that she wanted to do postdoctoral research in the United States, he circulated her credentials among the society’s members.

“After four days, Febina invited me to South Dakota State University to examine the Diaporthe species causing soybean disease in the United States,” Petrović recalled. Her 10-month residency, which began in August, is supported by a grant from the Serbian government and funding from the Institute of Field and Vegetable Crops. She also received support for her SDSU research from the North Central Soybean Research Program and the South Dakota Agricultural Experimental Station.

The world has two main types of stem canker—the Northern variety, which likes cool temperatures and affects both South Dakota and Serbian soybeans, and the Southern, which can survive high temperatures. Both types like moisture, Petrović explained.

Plants are infected when raindrops hit pathogen-containing plant residue and splash the fungus spores onto the young soybean plants. “At the end of July or beginning of August, when soybeans are in their pod-fill stage, we see the first symptoms, dark brown lesions the spread up and down the plant,” she said.

“Planting resistant genotypes is the best option for producers,” Petrović explained.  In Serbia, she said, “Our genotypes have good field resistance, but not complete resistance. However, we are trying to find the most resistant or tolerant soybean genotypes.”

In the United States, five Diaporthe species are causing soybean disease, according to Mathew. She and North Dakota State University Extension Plant Pathologist Sam Markell found Diaporthe gulyae, which causes Phomopsis stem canker in sunflowers, associated with stem disease on soybeans.

Recently plant scientists have seen an increase in soybean diseases caused by Diaporthe (Phomopsis) species in the United States, according to Mathew. Petrović’s research will help identify the pathogens behind this increased disease prevalence.

“I want to know more about the relationship among the Diaporthe species,” said Petrović. To do this, she’ll examine the pathogens’ diversity using phylogenetics. She and Mathew will also screen soybean genotypes to identify sources of resistance to Diaporthe species that will help breeders develop resistant soybean cultivars.

This research will help scientists develop strategies to manage the disease that will benefit farmers not only in the United States, but also in Serbia.

SEE ORIGINAL STUDY

 

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science daily -logo

These  can dive, swim, and jump like dolphins

Puffins, flying fish, and dolphins are naturals in both the air and sea, moving from one to the other with ease. Now, for the first time, a tiny robot is joining their routine. The bee-sized bot, which can fly by flapping its tiny wings, has been re-engineered to dive into water, swim, take off again, and land safely. Once it dries off, the “robo-bee” can repeat the whole routine—or go back to flying. But engineering for water wasn’t easy. The researchers realized early on that their 175-milligram bot needed help staying upright underwater. So they added stabilizing cross beams and slowed down how quickly it beat its wing: In air, the wings flap about 250 times per second; in water, they average about nine beats per second. Any faster than that, and the bot starts to tilt and twist and can even fall apart. The bot also needed help breaking through the water’s surface tension, so the researchers figured out how to give it a push with an electrical device that converts water into oxygen and hydrogen, plus a “sparker” that can ignite these gases. After 2 minutes, the gases build and make the bot buoyant enough to get its wings out of the water. Then the spark blows up the gases, and the bot shoots up about 35 centimeters at a speed of more than 2 meters per second, the researchers report today in Science Robotics. The bot can’t fly again until it dries out, but its design helps it glide to a safe landing. And though it’s unlikely to perform at Sea World, this versatile bot may one day help with ocean search and rescue, fish surveys, and environmental monitoring.

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