Safeguarding against locust invasion

Nomadacris septemfasciata hopper band
Nomadacris septemfasciata hopper band. Photo from Wikimedia Commons

Fourteen years after the introduction of the fungal biopesticide—Green Muscle®—developed by IITA’s scientists with their partners, the product is gaining more prominence as a control option against invasive locusts that threaten African farmlands.

Recently, the biopesticide, which had been picked up by a South African firm for commercialization, averted the devastation of farmlands from an invasion of red locusts in Tanzania.

The rapid intervention by the Food and Agriculture Organization (FAO) using the biopesticide drastically reduced locust infestations in Tanzania and prevented a full-blown invasion that could have affected the food crops of around 15 million people in the region.

Ignace Godonou, entomologist based in IITA-Bénin, was part of the team that developed the biopesticide more than a decade ago. He said that, if left uncontrolled, a full-blown invasion would have caused a major setback to food security in the region.

“We are happy that Green Muscle® has proved effective in controlling locusts and is now widely used.”

Green Muscle® is a fungal biopesticide that was developed in response to a locust plague in the 1980s. It is effective against most locust and grasshopper species; it is safe, does not affect other species, and can be sprayed in the same way as chemical pesticides. A fungus, Metarhizium anisopliae, which is common in the tropics and subtropics, is used to kill the pests.

Top: Healthy hopper; Bottom: Hopper infested with Metarhizium
Top: Healthy hopper; Bottom: Hopper infested with Metarhizium. Photo by IITA

If not restrained, large swarms of red locusts will fly over vast areas of farmland, traveling daily more than 20 or 30 km and feeding on cereals, sugarcane, citrus and other fruit trees, cotton, legumes, and vegetables cultivated by poor farmers. A red locust adult consumes roughly its own weight in fresh food, about 2 g, in 24 hours. A very small part of an average swarm (about 1 t of locusts) eats the same amount of food in one day as around 2,500 people.

The biopesticide was developed by an IITA technical team under the LUBILOSA project (LUtte BIologique contre les LOcustes et les SAuteriaux – Biological Control of Locusts and Grasshoppers). It has proved effective in controlling locusts in the Sahelian region, including the Republic of Niger and Mauritania.

Godonou said that initial field trials of the product were conducted in the Republic of Bénin under the close watch of IITA scientists, based in Cotonou. The subsequent large-scale field trials were held in Niger and Mauritania.

“Mass production of the fungus for small- to large-scale field trials also started at IITA-Bénin,” he added.

“Moreover, it can persist in the ground for several weeks or for up to a year after spraying, continuing to attack and kill healthy locusts and grasshoppers. The fungus is very safe and has a narrow range of hosts,” said Godonou.

This environment-friendly alternative to synthetic chemical pesticides weakens and kills the locusts in 10 to 14 days, continuing to attack and kill the grasshoppers. It remains effective under prolonged dry conditions and is therefore more effective as a control agent. The fungal spores are suspended in an oil solution, giving the product its green color.

Apart from IITA, other leading institutions in the LUBILOSA project were the Commonwealth Agricultural Bureau International in the UK, and the Département de Formation en Protection des Végétaux in Niger, with many partners drawn from donors, several research institutes, national agricultural research and extension systems, nongovernmental organizations, FAO, private sector companies, and farmers.

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