Scientists fight locusts with green pesticide

By BOB KOIGI

Scientists want widespread uptake of a locust bio-pesticide, whose success in Tanzania saved over 15 million people from starvation.

The push comes a time when more than 100,000 farmers in the country have between this and last year recorded up to 40 per cent low yields due to locust invasion.

Locust swarms lay waste to crops, with just a small part of a swarm, around a tonne of locusts, eating the same amount of food in one day as around 2,500 people, according to the UN Food and Agriculture Organisation (FAO).

Traditional synthetic pesticides have offered low respite due to the harm they cause to the environment and the soil.

However, the bio-pesticide, dubbed Green Muscle, is proving a sure bet due to its environment-friendly nature since it is non-toxic to locust predators.

“This means that even birds that feed on the dead locusts cannot be harmed,” said Dr Wilfred Otani from the International Centre of Insect Physiology and Ecology (ICIPE), who is among the chief campaigners of the bio-pesticide.

Green Muscle consists of spores of the fungus Metarhizium anisopliae suspended in mineral oils.

The fungi grow in the locust, producing a toxin and weakening them, making them easy prey for birds and lizards. Most infected locusts die within one to three weeks, depending on the temperature and humidity.

Various pests

The pesticide has an 80 per cent mortality rate. It kills only locusts and grasshoppers, unlike chemical pesticides, which can harm a wide range of organisms.

Even the birds and lizards that eat the treated locusts suffer no side effects. The persticide can persist in the ground for several weeks up to a year after spraying and continues to attack and kill locusts and grasshoppers. In 2005, a locust invasion hit Tanzania. However, swift intervention by FAO prevented a full blown invasion.

The organisation also scaled up its use in Malawi, Mozambique and Senegal, countries that are constantly threatened by grasshoppers.

“Its affordability is another of its selling point,” added Dr Otani. “A hectare can be sprayed with a dose worth Sh1,500 and majority of small-scale farmers do not even have a hectare, hence its economic sense.”

Only recently, Turkana farmers woke to the horror of a locust invasion on a scale never experienced before, which brought yields down by a staggering 40 per cent.

Agricultural officials from the area said more than 10 acres of the irrigated crop land has been hit by the locust invasion, whose origin could not be traced.

The deadliest locust invasion in Kenya was in 2007, when desert locusts from Ethiopia crossed into Kenya and descended on farms around Mandera in North-Eastern Province, which was already struggling with food security.

More than 200 farming families lost their vegetable and cereal crops, with many more losing their livestock due to locusts invading their pasture.

The families were placed under relief aid for a whole year having lost everything on their farms.

However, scientists saw it as a wake up call and have been pushing for preparedness, as Kenya still remains vulnerable to more attacks due to its shared border with locust-infested Ethiopia.          

   —FarmBizAfrica