By DAVID NJAGI, TEA Special Correspondent
IN SUMMARY
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An ongoing study shows that new stem borer species are colonising maize farms in the region, and could cost farmers about 88 per cent in crop losses.
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The new stem borer species are projected to attack Kenya, Uganda, Tanzania, Malawi and Ethiopia, according to Bruno Leru, the lead researcher of the IRD-Icipe programme.
Maize farmers in East Africa have been warned of a looming stem borer infestation weeks after the onset of the long rains.
An ongoing study by the French research organisation, Institut de Recherche pour le Développement (IRD) and the Nairobi-based International Centre of Insect Physiology and Ecology (Icipe) shows that new stem borer species are colonising maize farms in the region, and could cost farmers about 88 per cent in crop losses.
The pest is known to swarm three weeks after the first rains, meaning the infestation will get worse, according to George Ong’amo, a research consultant with the IRD-Icipe stem borer biodiversity programme.
“Farmers who plant immediately after the rains expose their crop to the moths that attack when the maize is young,” said Dr Ong’amo.
Farmers in low altitude areas are expected to face the heaviest infestation due to high temperatures, where the dominant species is chilo partellas.
The colonising bug in high altitude areas is brisseola fusca. But while farmers in these regions will be spared heavy losses, this species can be as lethal because a single pest can bring down a whole plant on its own, Dr Ong’amo added.
The new stem borer species are projected to attack Kenya, Uganda, Tanzania, Malawi and Ethiopia, according to Bruno Leru, the lead researcher of the IRD-Icipe programme.
“The pests usually feed on wild grasses that are related to maize and sorghum,” said Dr Leru. “But when they cannot find these sources they swarm on staple crops because they are more nutritious than the wild crops.”
The five-year study is testing several approaches to protect farmers from stem borer raids, including cultural control or delayed planting. Farmers are advised not to plant two weeks after the onset of the rains in the hope that the pests will be lured to other plants like wild grasses.