Farmers in Eastern Province have been urged to be on the lookout following an outbreak of the army worm pests in Bugesera District. The deadly pests attacked a number of sweet potato gardens, including a two and half hectares of orange-fleshed sweet potato rapid multiplication field belonging to International Potato Centre (CIP) in Karama, Leonidas Nzaramba, CIP the field supervisor, said.

Nzaramba added that quick response from CIP by immediately spraying the affected gardens prevented the pests from inflicting huge damages.

"With the continuous spray and hand-picking of the pests, the vines were not affected and therefore still have chance to keep growing,” Nzaramba added.

He also stressed that farmers need to adopt the habit of checking on their crops more often for any pests, saying that early detection is key in the fight against the army worms.

The fall armyworms invaded Rwanda early last year, destroying maize and sweet potatoes.

Nshimiyimana Jean Claude, an agronomist at International Potato Centre, said farmers should be well-equipped and knowledgeable about how to control the pest to minimise attacks and damage.

"Although pesticides, such as Rocket, are reliable, farmers must have more options, including biological control methods, where a farmer may use palm oil to attract ants which attack the army worms,” he said.

The agronomist also advised farmers to always use clean planting materials.

More about the fall armyworm

The armyworm pest is a serious threat to sweet potato and maize, among other crops, as their eggs have a short gestation period of two to four days to hatch into a larva. It’s the larvae that feed on plant leaves, including potatoes. A swam of armyworms can destroy a large field overnight.

Their lifecycle takes 22-29 days and the adult female moth lays about 1,000 eggs in the soil. Therefore, armyworm pests remain a threat to crop production since there is a possibility of repeated attacks.