Decoding the genome of a gigantic insect could help tackle the devastating locust crises

A “ game-changing ” study deciphering the genetic material of the desert locust by researchers at the University of Leicester could help combat the devastating crop behavior of the notorious insect pest, which is currently aggravating the hunger crisis in many developing countries.

The study is expected to provide the basis for developing ‘smart pesticides’, which act with surgical precision by harnessing specific signals from locusts to the nervous system, to kill or disable their swarming behavior, without harming other organisms.

The full set of desert locust genetic information could have important international implications for countries such as East Africa, the Arabian Peninsula and Southwest Asia, which this year have been suffering from the most devastating desert locust crises in decades despite the generalized control. operations that are still in progress.

According to the Food and Agriculture Organization of the United Nations (FAO), a swarm of locusts can contain around 40 million insects per square kilometer, which each day can eat the same amount of food as 35,000 people. FAO estimates that 42 million people are currently facing severe food insecurity caused specifically by the desert locust.

Dr Tom Matheson said: “The incredible devastation these voracious insects can wreak on food crops and pastures affects the livelihoods of hundreds of thousands of farmers and exacerbates the risks of starvation for the general population in already vulnerable regions. .

“The desert locust genome provides key information that could be a game changer for the developing world and a huge economic leap for countries struggling to feed their populations.

“Addressing locust pests and controlling swarms will never be easy due to the challenging conditions in the large affected areas, but with the right information and research at hand, we hope that future approaches can be more effective.”

He added: “If climate change makes locust infestations the ‘new normal’, we will need all hands on deck through in-depth research and improved technology to help in the fight to control swarms.”

Desert locust swarms are a major economic problem in more than 65 countries, in more than 20 percent of the world’s total land area. Authorities in affected countries have been conducting aerial pesticide spraying, but the scale of the infestation often exceeds local capacity, as desert locusts can travel up to 150 km (95 miles) in one day, crossing borders. national roads and rugged terrain in regions with little road infrastructure.

While locust swarms are famous for the great damage they inflict on agriculture, their genetic material (‘genome’) is famous among researchers for its enormous size. With over 8.8 billion DNA base pairs (8.8 ‘giga-bases’), the desert locust genome is the largest insect genome sequenced to date and more than 2.8 times larger than the human genome.

Dr Swidbert Ott added: “We still do not understand the genetic instructions that cause locusts to behave so differently from common grasshoppers, and to such a damaging effect. Until now, a major obstacle has been the lack of the sequence. of the desert locust genome that contains the answer to what makes a grasshopper a locust.

“We hope that our data can facilitate the development of novel and more sustainable methods to control swarm outbreaks. With the information from our research now available, there is a unique opportunity for innovators to create a smart pesticide that targets lobsters, but not other insects, crucial to the ecosystem, such as pollinators. “

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For more information or interviews with the authors, please contact Corinne Scotland at the University of Leicester Press Office on 07590403166 or [email protected]

Images are available upon request.

1. First draft of the genome assembly of the desert locust, Schistocerca gregaria. F1000 Research 2020, 9: 775. doi: 10.12688 / f1000research.25148.1 is published in the journal F1000 Research.

2. The experts worked with an international team of specialists to achieve the first sequencing of the complete set of genetic instructions (the “genome”) of the desert locust.

3. An adult desert locust can consume approximately its own weight in fresh food per day: that is approximately two grams per day. A 1 km² swarm contains around 40 million locusts, which eat the same amount of food in one day as 35,000 people, 20 camels or 6 elephants. During quiet periods (known as recessions), lone locusts are found in small numbers scattered throughout the deserts of North Africa, the Middle East, and Southwest Asia. This arid zone is about 16 million km² in size and includes about 30 countries. It’s called a recession zone. During a plague, swarms can also invade other countries and a larger amount of land equivalent to about 20% of Earth’s land can be affected (area of ​​invasion). You can find more information from FAO here.

4. Among the swarm outbreaks, desert locusts lead solitary lives that behave like a harmless grasshopper. Locust swarms reflect the remarkable ability of desert locusts to transform from a ‘solitary phase’ of solitary life to a ‘gregarious phase’ swarming that is attracted to other locusts and therefore tends to aggregate in still numbers. greater. Not only do locusts behave very differently once this transformation has occurred, but they also look so different that the two phases were confused with separate species until less than 100 years ago. This ability of desert locusts to transform into the swarm phase is encoded in their genes. Under favorable conditions, the population can multiply by 20 every three months.

Dr Tom Matheson, University of Leicester, Department of Neuroscience, Psychology and Behavior: [email protected]

Dr Swidbert R. Ott, University of Leicester, Department of Neuroscience, Psychology and Behavior: [email protected]