SA unlikely to be hit by major locust outbreak

South Africa’s agricultural regions are not expected to see a significant locust outbreak this season, according to Dr Gerhard Verdoorn, operations and stewardship manager at CropLife South Africa.

SA unlikely to be hit by major locust outbreak
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Cooler temperatures and high soil moisture levels across the Karoo and Kalahari have so far prevented conditions favourable for large locust swarms.

Speaking to Farmer’s Weekly, Verdoorn said: “I don’t see any indication yet in the Karoo or the Kalahari of locusts emerging. What worries me is that I see solitary grasshoppers all around Gqeberha, telling me there are a lot of female grasshoppers, and I wouldn’t be surprised to find them in the Karoo as well.”

Yet, despite the presence of these isolated grasshoppers, Verdoorn added that current conditions weren’t conducive to a full locust outbreak.

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“Why we haven’t got an outbreak yet, even though it’s now the first week of November, is because the Karoo is still not warm enough,” he said.

Cooler temperatures in this region, coupled with high soil moisture, are keeping potential outbreaks at bay. Verdoorn also mentioned that while there was potential for a smaller outbreak if temperatures rose, conditions were unlikely to support a severe locust infestation this year.

“There’s a possibility for a small outbreak this season, from now until maybe May, if temperatures start increasing,” he said.

Soil moisture from recent winter rainfall in the Karoo is high, but temperatures would need to rise significantly above 31°C to trigger a locust emergence, a scenario he deems improbable this season.

Reflecting on previous years, Verdoorn said: “What I know from the beginning of this year is that there were small outbreaks in Namaqualand, far north-west from the typical Karoo and Kalahari regions. But it was nothing significant. It was never like what happened in 2021 and 2022.”

In the rare event of an outbreak this year, he predicts it would be limited and manageable, with greater risks possibly emerging in the following season if environmental factors shift.

Verdoorn said that isolated grasshoppers, unlike locusts, pose minimal agricultural risk.

“There’s the elegant grasshopper, a very colourful one that you find up north, and then we’ve got the longhorn and shorthorn grasshoppers. They might damage grazing areas or gardens, maybe 1% or 2%, but their impact is not even visual, let alone economical,” he said.

The real threat comes only when locusts shift into what he described as a “communal phase or swarming phase,” where locusts gather in massive numbers, potentially devastating crops and grazing land. However, the risk remains low for South Africa’s citrus growers.

“Interestingly, when locusts moved into the citrus farming areas of Hankey and Patensie in the Eastern Cape, they caused virtually no damage. I don’t believe they like the citrus oil in the plants.”

He added that the locusts had possibly also reached the end of their lifespan by the time they reached the citrus farms.

In the event of a sudden locust outbreak, CropLife South Africa collaborates closely with farmers, the Department of Agriculture, and agricultural associations to provide early warnings and mobilise resources. According to Verdoorn, farmers inform CropLife when they see tiny black locusts called ‘hopper bands.’

“When I get these calls, I contact the Department of Agriculture’s head office, and they activate their teams to control locusts while they’re still small, which minimises environmental impact and keeps pesticide use low.”

Preventative measures like these ensure that any potential locust swarm is managed before it becomes airborne and spreads widely.

“We always aim to prevent the locusts from becoming flyers, because if they cover vast areas, we’d need helicopters for pesticide applications, which is costly and environmentally taxing,” he said