October 26, 2005

Organic pesticide can kill locusts, scientist says

By George Obulutsa

NAIROBI (Reuters) - Researchers have developed an organic
pesticide that can control deadly locust swarms in Africa,
reducing the need to use traditional insecticides that harm the
environment, a senior scientist said on Wednesday.

Last year West Africa's worst locust infestation for more
than a decade wreaked havoc and worsened food shortages in some
of the world's poorest nations, causing major damage to grain
crops across a region where many are subsistence farmers.

Such swarms could now be prevented from forming by spraying
juvenile locusts with a scent, or pheromone, taken from adults,
scientist Christian Borgemeister told Reuters in an interview,
citing tests carried out in Sudan "with very promising

Spraying breaks up the groups, or bands, young locusts live
in and exposes them to predators, said Borgemeister, director
general of the non-profit International Center of Insect
Physiology and Ecology (ICIPE), based in Kenya.

"It destroys the bands. The insects are highly stressed.
They suffer high natural mortality and fall victim to many
natural enemies like birds," he said.

Borgemeister said the pheromone was environmentally
friendly and cheap to develop, and its use alongside other,
more expensive insecticides could reduce the amount of those
insecticides used in efforts to kill locusts.

The organic pesticide can also be used on its own, he said.

The major element in the pheromone was phenylacetonitrile
(PAN), he said. "The beauty of a combination of PAN and
conventional insecticide is that you reduce the concentration
of the insecticide more than four-fold," Borgemeister said

"Traditionally in outbreak situations of locusts, they are
controlled by insecticides. Insecticides are hazardous to the
environment ... cause mortality not only in locusts but other
insects," Borgemeister said.


His organization is testing the pesticide with support from
the U.N. Food and Agriculture Organization, the U.S. Agency for
International Development and the Swedish International
Development Cooperation Agency.

Borgemeister said the pesticide had been registered for
testing in Sudan and he planned to do more extensive trials
that could enable it to be authorised for use in about a year's

"We hope that in a year from now we will be able to provide
PAN (for public use) and to recommend PAN in combination with
either a soft dose of insecticide or a significant reduced dose
of Green Muscle fungus (a biopesticide) for locust control,"
Borgemeister said.

ICIPE plans to commission a company to manufacture the
pesticide when it is approved for public use.

"We're developing something, and then we are handing it
over as a public good," Borgemeister said.

Part of ICIPE's research is to explore any possible side
effects of the pheromone on other organisms. Borgemeister said
these would be minimal.

"We believe as scientists, since this is a pheromone, the
chances that this will have detrimental side effects on other
organisms are close to nil," Borgemeister said.