In January of 2017 the armyworm (a species indigenous to South America) invaded South Africa’s crop lands, causing devastation to crops, especially maize- a staple grain to Africans. In late 2016 they had already overwhelmed maize crops in Zambia, Zimbabwe, Mozambique, Namibia and Malawi. This caused food shortages and food price increases to regions that were already affected negatively by drought. The problem seen for the future is further crop devastation unless something can be done about the armyworm (of which there are 31 species!).
The South American armyworm burrows into the stem of juvenile maize plant’s stems, destroying it from the inside and killing the plant. The armyworms are more commonly found feeding on the leaves before the plant is spoilt.
The outbreak was most likely caused by the rainy season after months of drought when the armyworms came out to feed on fresh vegetation, in this case, Southern Africa’s newly planted crops. They lay up to 2000 eggs in their lifespan which hatch quickly, causing such apocalyptic outbreaks.
Because the South American armyworm is an alien in South Africa there was no pesticide made specifically for it with clearance for use. Luckily there are ways to prevent an outbreak to know should your agricultural land be ambushed by a South American armyworm militia:
Prevention is the best cure!
Pheromone traps monitor when the moths arrive to lay the eggs that spawn into armyworms.
Monitor your crops in the early spring and wet seasons. By closely monitoring your crops in this time you may spot signs of armyworms early enough to take action.
Avoid using the wrong pesticides as this may kill off the armyworm’s competitors, making way for them to wreak havoc. Many of these “pests” like ladybugs eat armyworm eggs.
Attract competitors by turning the soil in the autumn you leave larvae exposed to be eaten by birds.
Use neem oil to discourage the eggs from hatching as well as killing off larvae and mites. It will even cure fungus growth on your crops.