‘Be able to spot the difference between fall and African armyworms’
FARMERS must be able to accurately identify the fall and African armyworm pests to administer the correct control measures that will address the problem, an expert has said.
Migratory Pest Control Department acting chief director Mr Shingirayi Nyamutukwa yesterday said by understanding the distinctions between the African armyworm and the fall armyworm, farmers can take targeted action to protect their crops and mitigate the devastating impact of the pests on their livelihoods.
He said: “The distinctions between the two armyworms, which include their appearance, feeding habits, egg-laying patterns and lifespans can help identify the pest damaging crops and control it correctly.
“One way to identify the African armyworm is by observing its coloration. When found alone, it exhibits a vibrant green hue, while a multitude of these worms feasting on maize crops takes on a velvet black appearance and a V-mark on its forewings. On the other hand, the fall armyworm can be recognised by its green or brown colour, with four dots at the end of its abdomen and a distinctive “Y” mark on its forewings.”
The damage caused by these pests also differs. The African armyworm, when grown, consumes the entire leaf of the plant from the beginning to the mid-rib. Fall armyworm initially creates pinholes in the leaves when it is small but as it grows it hides within the heart of the plant and damages emerging leaves leaving them tattered.
He added that targeted crops varied between the two species. The African armyworm mainly feeds on grass related crops such as maize, sorghum and grazing grass. In contrast, the fall armyworm can target a broader range of crops including maize and sorghum but it notably avoids grazing grass. It has been known to damage broad-leafed crops like sugar snaps, cotton and flowers.
“How they lay eggs also differs. The African armyworm lays its eggs in pasture grass, and the worms later infiltrate farms from there. Conversely, the fall armyworm deposits its eggs directly on plants. Farmers are advised to inspect the inner leaves at the heart of maize plants during field scouting to detect the presence of these eggs,” he said.
He also emphasised that both species endured for around 30 to 33 days, but the fall armyworm can survive for up to 13 generations on a plant. The African armyworm’s lifespan spans from December to April, as it cannot survive the winter.
These armyworm infestations pose a severe threat to agricultural production, Mr Nyamutukwa urged farmers to remain vigilant in identifying and managing the armyworm through scouting and using pesticides to control them.
“Early detection and prompt implementation of integrated pest management strategies can help mitigate the damage caused by these pests,” he recommended.
African armyworm has been reported in seven districts in four of the country’s 10 provinces where they have damaged 192, 5 hectares of maize, 69,3 hectares of sorghum, less than one hectare of finger millet and 32 hectares of pastures with authorities warning the public around the country to be on the lookout for the pest.
Reported cases are in Mudzi, Mashonaland East, Mbire in Mashonaland Central, Zvimba, Sanyati and Makonde in Mashonaland West and Gokwe North and South in Midlands.