Africa looks to biocontrol to reduce fall armyworm problems

Fall armyworm (Spodoptera frugiperda) has been a devastating pest of cereal crops in Africa since 2016, when it was introduced from the Americas. It has since spread to over 20 countries in sub-Saharan Africa. Just this year, it was found in India as well.

Fall armyworm is particularly dangerous because it has a wider host preference than related species (it feeds on 150+ plants including rice, sugarcane, legumes, and cereal crops). Grains like corn, sorghum, and millet are not only a food staple for hundreds of millions of people, they are the root of other commodities like forage and biofuels.

Pests, drought, and extreme poverty already afflict many farmers, and there are both knowledge and income gaps that prevent wide use of pesticides or other control tactics.

Enter: the good news.

Tiny, tiny wasps.

We know that beneficial parasitoid wasps help regulate cutworm and armyworm populations, but on their own, they cannot help in an outbreak situation because there are simply not enough of them to make an impact. Unless – their numbers could be exponentially increased for very little money and people could be trained to ‘raise’ them.

One tiny wasp, in particular, Telenomus remus, already exists in the region, is easy to rear, and is not deterred by the ‘hairy’ covering that protects fall armyworm egg masses. Even better news: the technique of raising the wasps is being taught to local farmers so that the strategy can be implemented large-scale.

Scientists have been able to implement a mass-rearing program to enhance native natural enemies that attack fall armyworm eggs and larvae.

Fun fact: Some of our own Beaver emeriti (P. Jepson, D. McGrath) are working towards developing solutions to the fall armyworm crisis in Africa.

References

• Bateman, ML, Day, RK, Luke, B, Edgington, S, Kuhlmann, U, Cock, MJW, ‘Assessment of potential biopesticide options for managing fall armyworm (Spodoptera frugiperda) in Africa,’ J Appl Entomol. 2018;00:1–15.

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