South African systems set up for pest invasions

South Africa has the ability to deal with most opportunistic pest invasions whether from armyworms or locusts, said Dr Gerhard Verdoorn, toxicologist and pest control specialist.

Verdoorn said he would be surprised if there were no pest outbreaks in South Africa this season, but this was essentially no cause for panic.

“There is enough (environmentally-friendly) pesticide in the country to effectively manage and contain pest outbreaks,” he said.

The country was very fortunate to have a highly competent, and experienced team, in the department of agriculture, forestry and fisheries (DAFF) to respond to pest threats, Verdoorn said.

Pest expansions to the North

Initial reports of fall armyworm invasions came from Zambia at the beginning of December, with subsequent reports of outbreaks in Zimbabwe and Malawi.

More than 10% of Zambia’s maize lands had been destroyed and seven of Zimbabwe’s eight provinces have been invaded by the fall armyworm, according to a Bloomberg report.

Farmer vigilance and daily visual surveys were absolutely critical for good control. Report immediately any sighting of green worms with yellowish or cream coloured bands, even without confirmation, Verdoorn said.

“Containment needs diligent field and veld reconnaisance checks every day. Farmers should phone me right away if they see signs of the pest, so that I can notify the chaps at DAFF. Don’t wait for the population to explode.”

The pest control expert warned against the use of organophosphates (including chlorpyriphos), since this would cause dramatic and wide-spread poisoning of birds.

“There are enough ‘soft’ (environmentally-friendly) chemicals for the effective control of fall armyworm; let’s use those.”


The dry, warm conditions over most of the Karoo are ideal for locusts, and farmers must be on the lookout for these pests. This is particularly so in the area extending from the south of Bloemfontein to Graaf-Reinet, once rain has fallen, Verdoorn said.

Possible imports

Agbiz economist, Wandile Sihlobo, said South Africa and Zambia were the primary and secondary producers in the region and outbreaks in countries to the north of SA would have an impact on local grain markets.

The year ahead now presented a greater probability that southern Africa would be a net maize importer. Inevitably, this would put upward pressure on the maize price, Sihlobo said.

The fall armyworm, generally confined to South America where it causes large-scale damage, made its first appearance on the African continent last year.

Scientists think that climate change has made the trans-continental leap possible, by enabling migration through the jet streams of the high atmosphere.

Verdoorn said the standard control protocols for the regular armyworm that occurs in South Africa, should apply for the fall armyworm.

Contact Dr Gerhard Verdoorn on cell phone: +27 82 446 8946.

Recommended pesticides available in South Africa for armyworm control that do not endanger migratory birds such as storks and cranes:

■ Cypermethrin EC (registration L4644).
■ Decis Forte (L6563).
■ Decis (L1741).
■ Fury 10EW (L6696).
■ Alpha-thrin 100SC (L7262) Concord (L7143).
■ Qwemifast (L721 1).
■ Ripcord EL (L4953).
■ Ripcord 200 EC (L5603).

These chemicals are registered for the control of armyworms on veld and pastures. Other registered chemicals methomyl (a carbomate) is extremely toxic to birds and chlorpyriphos is toxic.

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