Global warming? No. Imported from South America, probably by an imported plant, and spreading around the continent.
Slow government response, and farmers believe the rumor that pesticides won't work
most farmers are still not aware of what can be done to reduce it's damage. Some farmers in Gokwe district bought all kind of theories about a mysterious worm due to lack of information and clear guidance from the government. As a result some healthy looking crops were left at the mercy of the devouring fall armyworm. Many of the farmers are now counting huge losses....
FAO warned that Zimbabwe is likely to be the hardest hit with 130,000 hectares of maize and corn crops largely affected. So far the fall armyworm has spread in at least 10 provinces in Zimbabwe.
Despite the farmers' concerns, the government sees no urgency or panic regarding the armyworm. The head Plant Protection Research Institute at Zimbabwe’s Ministry of Agriculture, Godfrey Chikwenhere, said the yield reduction obeserved was minimal. "The only issue now is that we are using a substantial amount of money on chemicals," he said."
Though from the casual observer when you see the worm and all the plant being [attacked] you might estimate that the yield is very high," Chikwenhere added.The caterpillar stage is the dangerous one that eats the crops. Ah, but then it turns into a moth, which is how it can migrate so quickly into new area.
this WIKIHOW is more about how gardeners can control it in rich countries
Why is it such a threat to farming? It is very hungry (and not picky) - This pest targets maize (corn) and other cereal crops, like its African namesake, but it also attacks cotton, soybean, potato and tobacco crops. When it does invade, up to three-quarters of the crop can be destroyed.
Unknown enemy - Governments, communities and farmers have no previous experience of dealing with the new pest, which may be even harder to deal with than its native equivalent.
Gizmodo articcle on efforts to control the pest. They blame global warming of course.
As if the drought/rain cycle was due to global warming, not a normal event that has been going on for years.
Actually all they say is that the moth didn't spread quickly during the drought, but once the rain came and there was a lot of good crops to eat it spread.
Nature article on droughts in Africa:
Our data indicate that, over the past millennium, equatorial east Africa has alternated between contrasting climate conditions, with significantly drier climate than today during the 'Medieval Warm Period' (approx ad 1000–1270) and a relatively wet climate during the 'Little Ice Age' (approx ad 1270–1850) which was interrupted by three prolonged dry episodes.
We also find strong chronological links between the reconstructed history of natural long-term rainfall variation and the pre-colonial cultural history of east Africa4, highlighting the importance of a detailed knowledge of natural long-term rainfall fluctuations for sustainable socio-economic development.