Plant-Parasitic Nematodes and Food Security in Sub-Saharan Africa

Annual Review of Phytopathology

Vol. 56:381-403 (Volume publication date August 2018)
First published as a Review in Advance on June 29, 2018







Sub-Saharan Africa (SSA) is a region beset with challenges, not least its ability to feed itself. Low agricultural productivity, exploding populations, and escalating urbanization have led to declining per capita food availability. In order to reverse this trend, crop production systems must intensify, which brings with it an elevated threat from pests and diseases, including plant-parasitic nematodes. A holistic systems approach to pest management recognizes disciplinary integration. However, a critical under-representation of nematology expertise is a pivotal shortcoming, especially given the magnitude of the threat nematodes pose under more intensified systems. With more volatile climates, efficient use of water by healthy root systems is especially crucial. Within SSA, smallholder farming systems dominate the agricultural landscape, where a limited understanding of nematode problems prevails. This review provides a synopsis of current nematode challenges facing SSA and presents the opportunities to overcome current shortcomings, including a means to increase nematology capacity.




icipe logo

icipe Director General featured in The CEO Magazine

Dear Friends and Colleagues,

Greetings from all of us at icipe.

We are pleased to inform you that icipe Director General, Dr. Segenet Kelemu, has been featured in The CEO Magazine as one of the exceptional leaders from around the world, breaking ground and shattering the glass ceiling.

Please find below a link to the article:

We thank you for your support and look forward to our continued partnership.

With best regards, icipe


Molecular p p congress

Plant protection scientists,

Molecular approaches are currently among the most popular topics in biological sciences and provide many opportunities in the solution of various problems. We have witnessed common use of these approaches in the field of plant protection in the last decades. Many research projects related to entomology, plant pathology and weed sciences have been conducted using genomics, transcriptomics, proteomics, functional genomics, DNA-based diagnosis techniques, gene expression analyses and recombination studies. Significant progress has been achieved in the solution of pest, disease and weed problems in plant protection using molecular strategies. Consequently, molecular tools have gained significant attention in plant protection in Turkey as well as the world. There is an emerging need to have a platform for scientists working on molecular sciences related to entomology, plant pathology and weed science, to exchange ideas and provide support for one another. We are hoping we can contribute to the establishment of this platform by organizing the “1st International Molecular Plant Protection Congress”. The congress will be held at �ukurova University, Mithat �zsan Hall in Adana between April 10-13, 2019, under the coordination of �ukurova University, Ankara University and Turkish Ministry of Agriculture and Forestry.

The theme of the congress is “molecular approaches for better plant protection”. The purpose of the congress is to provide a platform where researchers can share their latest findings with each other and exchange the ideas. The official language of the congress will be English and the abstracts will be provided in the congress book. Full length article option will be available for authors. These articles will be peer-reviewed and be published electronically as proceedings under the web site of the congress. Specifically, select papers on insect molecular biology, physiology and biochemistry from keynote speakers and all presenters (oral or poster) will be considered for publication in the special issue of “Archives of Insect Biochemistry and Physiology”.

You could reach the congress web site from the link below:


We are hoping to see you at the “The First International Molecular Plant Protection Congress” in Adana between April 10-13, 2019.
Sincerely yours,
On Behalf of the Executive and Congress Organization Committees
Umut Toprak, Ph.D, Ankara University, Ankara, Turkey
M. Bora Kaydan, Ph.D, �ukurova University, Adana, Turkey
Sait Ert�rk, Ph.D, Turkish Ministry of Agriculture and Forestry, Ankara, Turkey


science d-logo

Seeing pesticides spread through insect bodies

September 19, 2018
Osaka University
A team provides insights into the distribution of pesticides within insects using a newly developed method of insect sample preparation.

Imidacloprid distribution (target m/z 211.07) in (A) imidacloprid-dosed flies and (B) blank control flies. The matrix was 2,5-dihydroxybenzoic acid and the measurement pitch was set to be 15?m. Color bar on the left shows the absolute imidacloprid intensity.
Credit: Osaka University

Pesticides have been linked with declining honey bee numbers raising questions about how we might replace the many essential uses of these chemicals in agriculture and for control of insect-borne diseases. As many governments seek to restrict uses of pesticides, more information on how pesticides affect different insects is increasingly beneficial. Greater insight into how these chemicals interact with insects could help develop new and safer pesticides and offer better guidance on their application.

Now a team at Osaka University has developed a new method of visualizing the behavior of pesticides inside insect bodies. Their findings were recently published in Analytical Sciences and highlighted on the journal’s cover.

As lead author Seitaro Ohtsu explains, “There have been no reports on the distribution of agricultural chemicals in insects to date. This is probably because it’s very difficult to prepare tissue sections of Drosophilia specimens for imaging studies.”

Researchers from Osaka University examined an insect from the Drosophila-family, a type of fruit fly which is widely used for testing pesticides. They developed a technique that let them slice the insect body into thin sections for analysis while preserving the delicate structures of the specimen.

Imidacloprid-a highly effective nicotine related pesticide -was chosen for the analysis. Applying their sample preparation method to insects treated with this chemical allowed the team to follow its uptake, break down, and distribution in the insects’ bodies.

The team applied a method that involves scanning a laser across the thin sections of the insect body to eject material from small areas of the surface. By analyzing the chemical composition of the ejected material with a mass spectrometer at different locations they were able to build up a picture of the pesticide and its breakdown products over the whole insect body.

Senior researcher Shuichi Shimma says “This is a timely contribution while the evidence for the negative effects of certain pesticides on ecosystems is accumulating. We hope our technique will help other researchers gain new insights into pesticide metabolism that might help limit the effects of pesticides to their targets without harming beneficial pollinating insects.”

Story Source:

Materials provided by Osaka University. Note: Content may be edited for style and length.

Journal Reference:

  1. Seitaro OHTSU, Masamitsu YAMAGUCHI, Hisashi NISHIWAKI, Eiichiro FUKUSAKI, Shuichi SHIMMA. Development of a Visualization Method for Imidacloprid in Drosophila melanogaster via Imaging Mass Spectrometry. Analytical Sciences, 2018; 34 (9): 991 DOI: 10.2116/analsci.18SCP04

Cite This Page:

Osaka University. “Seeing pesticides spread through insect bodies.” ScienceDaily. ScienceDaily, 19 September 2018. <www.sciencedaily.com/releases/2018/09/180919100908.htm>.

science d-logo

Watch a moth drink tears from a bird’s eye

In November 2017, ecologist Leandro Moraes of the National Institute of Amazonian Research in Manaus, Brazil, was in the middle of a research expedition in central Amazonia when he spotted something strange: a black-chinned antbird (Hypocnemoides melanopogon) resting on a branch with an erebid moth (Gorgone macarea) on the back of its neck. The moth was probing one of the bird’s eyes with its proboscis and appeared to be drinking from it. About 45 minutes later, Moraes came across a different moth drinking from the eye of another resting antbird.

Butterflies and bees also drink the eye secretions of other animals—butterflies are partial to basking crocodiles, whereas bees like turtle tears. But fast-moving birds are unlikely hosts for these insects. At night though, the metabolism of birds drops; that’s when nocturnal moths exploit their tears, Moraes speculates.

The moths probably acquire nutrients such as sodium and proteins from eye secretions of these birds, Moraes reports this week in Ecology. By sitting still on a resting bird’s back and using their long proboscis to reach its eyes, they avoid disturbing the bird, all the while maintaining a safe distance.

 Nematode book sikora_edited

Plant parasitic nematodes in subtropical and tropical agriculture

edited by:

Richard A. Sikora, Danny Coyne, Johannes Hallmann and Patricia Timper

Plant parasitic nematodes – overlooked, neglected, little known and mostly out of sight; surprising then that they cause billions of dollars’ worth of damage to global crop production annually.  In the tropics and subtropics they persistently undermine production, result in massive waste of disfigured and unmarketable produce, and literally plague some crops.

The latest updated edition of Plant parasitic nematodes in subtropical and tropical agriculture released in August, provides all that there really is to know about these pests on all major crops and crop products in the subtropics and topics. The new edition remains a truly practical book for use by agriculturists, researchers, teachers, students, extension workers and also administrators.

The 888 page book harnesses knowledge, experience and know-how from the leading authorities from across the world and is truly an encyclopedia of tropical nematology. The book contains over 250 high quality coloured photographs of damage symptoms and as in the earlier editions, the arrangement of each chapter remains practical and easy to use for both in chapter and between chapter analyses of specific topics of interest. The text has been completely updated and revised taking into consideration the new observations, records and results published since 1990.

The book has been expanded, for example, to include an important chapter on nematode ecology that reflects the importance of nematodes in soil biodiversity and as indicators of soil health. The chapter on management has been expanded to included practical data concerning the various elements for efficient management of plant parasitic nematodes as covered in the all the 18 crop chapters.

The editors reflect on the challenges and issues facing agriculture and nematology in the near and distant future and make suggestions for change, by attempting to anticipate how agriculture and nematology will look in the subtropics and tropics in the years 2050 and 2100. CABI has decided to make the book available both in hardcover and as an e-Book. Conceived in this way, we hope that this new edition will again be a truly useful and practical book for anyone dealing with plant parasitic nematodes and working in subtropical and tropical agriculture. We wish you success in your work to improve crop yields.

The Editors.


Climate Change and Superweed

Inside Science

Climate Change May Worsen Spread of Invasive Superweed

Much of the world’s farmland is already at risk from Palmer amaranth. The threat could spread further north as the climate warms.


Stanley Culpepper stands in a Georgia cotton field that is full of Palmer amaranth. 

Image credits: Courtesy of Stanley Culpepper

Rights information: This image may be reproduced only with this Inside Science article.

Friday, September 21, 2018 – 13:45

Nala Rogers, Staff Writer

(Inside Science) — It’s the worst weed in the whole country, according to the Weed Society of America. Palmer amaranth can grow to be 10 feet tall and as thick as a baseball bat. The weed has evolved resistance to multiple classes of herbicides, and it thrives in fields of corn, soybeans and cotton. Invaded cornfields can face losses of up to 91 percent.

“It’s a beast,” said Erica Kistner-Thomas, an ecologist with the U.S. Department of Agriculture’s Agricultural Research Service in Ames, Iowa. “It will take over the field and take all the resources — the nitrogen and the water — away from the crops.”

With tiny seeds that often hitch rides on farm equipment, the weed has already spread from its native Southwest desert into most of the continental U.S., and has established populations in Egypt, Israel, Turkey, Greece, Spain, Argentina and Brazil. A new study suggests that it will keep spreading across much of the globe.

Kistner-Thomas and her colleagues used software called CLIMEX to predict where palmer amaranth would be able to survive, based on its favored growing conditions for temperature and rainfall. According to the model, most of sub-Saharan Africa, India and Australia are ripe for invasion.

Under current climate conditions, the weed has trouble surviving in central Europe and the northern U.S., while northern Europe and Canada are mostly safe because they get too cold in winter. Indeed, Palmer amaranth has been found repeatedly in colder countries such as Germany, Norway and the United Kingdom, but has so far failed to establish populations there.

That could change if the world keeps warming. Under the most extreme or “business as usual” greenhouse gas emissions scenario, the amount of land with a suitable climate for palmer amaranth in the U.S. would increase by 21 percent by the year 2050, opening up an additional 17,267 square miles to invasion. In Canada, the amount of climatically suitable habitat would increase more than tenfold, from about 1,240 square miles to 13,795 square miles, according to the model. Kistner-Thomas published the findings earlier this year in the journal Agricultural & Environmental Letters, and presented them this summer at the Ecological Society of America meeting in New Orleans.

“Climate change is going to benefit this heat-tolerant weed,” said Kistner-Thomas. And, she added, “once it gets established, you’re not going to get rid of it.”

Some people may wonder why farmers are so eager to get rid of palmer amaranth, given that amaranth has been cultivated as a food crop for thousands of years and is now sold as a specialty item in American grocery stores. But while indigenous people in the Sonoran desert once gathered palmer amaranth for food, the types of amaranth that are grown as grains and vegetables today are not the same as palmer amaranth and related weeds. The modern cultivated species are highly nutritious and palatable, tasting somewhat like refined wheat flour, according to Jaime Amaya-Farfan, a food and nutrition scientist at the University of Campinas in Sao Paulo, Brazil.

Wild amaranth species are still sometimes crossbred with domestic amaranth or used as animal feed, according to José Arêas, a food biochemist in the Department of Nutrition at the University of Sao Paulo in Brazil. But in general, said Arêas, wild amaranth species are viewed as pests. Stanley Culpepper, a weed scientist at the University of Georgia in Tifton, has tried eating Palmer amaranth, and called the taste “horrible.”

Even if it were valuable as a crop, said Culpepper, palmer amaranth’s competitive vigor could be more a curse to farmers than a blessing. Crop rotation is essential for controlling pests and replenishing soil, but once a field had been used to grow palmer amaranth, it would be hard to grow anything else there because of the seeds left in the soil.

“There’s no way you can get them all. You’re going to spill some,” said Culpepper. “It would be a tremendous challenge, and could potentially be a nightmare.”

So what’s to be done about the weedy invader? Kistner-Thomas doubts it will be possible to completely prevent palmer amaranth from spreading, but there are ways to control it on farms. For example, the seeds don’t sprout unless they are exposed to sunlight, so farmers can till the soil to bury seeds or plant a cover crop to shade them, said Culpepper. It’s essential to act quickly, he said, and to use a combination of methods, since one approach won’t be enough.

Such efforts are costly. Ignoring inflation, Georgia cotton farmers spend about twice as much battling weeds today as they did in 2001, with the increase due to herbicide-resistant palmer amaranth, said Culpepper. But the efforts have worked to save Georgia’s crops, and Culpepper expects they could work in other places, too.

“When we started dealing with this plant, especially when it came to resistance, there was no research, there was no data, there was no information. There was no help,” said Culpepper. “No one would be walking into the same scenario we did, because there’s so much data currently available.”


Filed under:


Authorized news sources may reproduce our content. Find out more about how that works. © American Institute of Physics

Author Bio & Story Archive

Nala Rogers is a staff writer and editor at Inside Science, where she covers the Earth and Creature beats. She has a bachelor’s degree in biology from the University of Utah and a graduate certificate in science communication from U.C. Santa Cruz. Before joining Inside Science, she wrote for diverse outlets including Science, Nature, the San Jose Mercury News, and Scientific American. In her spare time she likes to explore wilderness.