Faced with agricultural losses caused by the fall armyworm, Togo is making a strategic shift by focusing on biological control.
In May 2025, the West Africa Food System Resilience Programme (FSRP) supported a mass release of parasitoids in several Planned Agricultural Development Zones (ZAAP), particularly in the East Plateaux and Kara regions.
This approach is based on the laboratory breeding of two particularly effective species of parasitoids (12,000 individuals of Cotesia marginiventris and 3,800 individuals of Chelonus insularis), which are introduced directly into maize fields to naturally neutralise the fall armyworm.
In order to maximise the effectiveness of this method, producers were made aware of the importance of not applying chemical treatments for two weeks after release. This allowed the parasitoids to establish themselves permanently in the treated areas.
Five months later, the initial results are promising.
Feedback from producers confirms a positive impact on maize yields. "This year, there have been far fewer attacks. The caterpillars haven't caused as much trouble as in previous years," says a producer from the Bouladè ZAAP in Assoli.
The trend is similar in the Atifoutou ZAAP. Attacks by the fall armyworm have been significantly lower this year, leading to improved crop quality and reduced use of chemicals.
This improvement in the field confirms the effectiveness of the biological approach adopted. To date, seven sites have already been successfully covered. The short-term objective is to extend the method to the entire territory, while continuing the mass rearing of parasitoids in Togolese laboratories.
For the FSRP, this initiative marks a major step forward in the fight against a scourge that has been ravaging Togo since 2016. It represents a tangible source of hope for maize producers across the country.
About the release of parasitoids
The release was carried out by slightly opening the cage containing the parasitoids to allow them to gradually escape. It is essential that the maize plants are between two and four weeks old after sowing at the time of the operation. This precaution has a significant effect on the parasitism rate of armyworms, particularly those in the L1 larval stage.
Once the cage is open, the agents move through the maize field, cage in hand, to facilitate the dispersal of the insects.
