10 things you need to know about the armyworm

Tuesday May 9 2017

Agriculture Cabinet Secretary  Willy Bett when he toured some of the maize farms affected by fall armyworm invasion in Kitale.

Agriculture Cabinet Secretary  Willy Bett tours maize farms affected by fall armyworm invasion in Kitale after which he launched a government programme to combat the menace. There are numerous interventions developing to curb the invasion. PHOTO | JARED NYATAYA | NATION MEDIA GROUP 

By BRIAN OKINDA
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Here are some facts on the fall armyworm affecting crops in Kenya.

1.    The armyworm derives its name from its feeding habits of eating everything within an area, and once the food supply is diminished, the entire “army” marches to the next available food source.

2.    The fall armyworm currently ravaging crops in the region is native to North and South America, in regions particularly east of the Rocky Mountains in the US, reaching northward into southern Canada.

3.    Fall armyworm invasions have been confirmed in 20 African countries, including the whole of East Africa and are extremely difficult to contain.

4.    Kenya has so far lost approximately 15,000 ha of maize, valued at Sh1.3 billion, to armyworms and the annual loss could be 40 million bags of maize, valued at Sh120 billion, assuming that the cost of one bag remains at Sh3,000.

5.    In Brazil, the third largest maize producer in the world, the fall armyworm is the most devastating pest, causing damage estimated at more than $400 million annually.

6.    Experts estimate that fall armyworms will cause damage worth about Sh310 billion to the maize crop in the affected regions in Africa in the next 12 months.

7.    The fall armyworm is more destructive, feeding on more than 80 varieties of crops, eating the leaves of the plant as well as its reproductive parts, compared with the African armyworm that Kenya is accustomed to, which feeds exclusively on maize, wheat, sorghum, rice and pasture grasses.

8.    Naturally occurring predators such as ground beetles and rove beetles may be important in keeping armyworm populations low. Research by scientists at Michigan State University has also found over 12 species of parasitic wasps and several flies that commonly attack armyworm larvae.

9.    The extensive drought that affected large swaths of sub-Saharan Africa for much of last year aggravated the armyworm invasion, as it creates the lengthy hot, dry conditions in which the worm thrives. 

10. Cassava is the only major crop that appears to be able to resist the pest, probably because it produces cyanide.

All in all, early detection of the worm’s infestation plays a critical role in mitigating its spread.