Monitoring and Assessment of the Damage of the Fall Armyworm Spodoptera frugiperda , J.E. Smith (1797) on Rainfed Crops (Maize, Sorghum and Millet) in Niger

Abstract

Fall armyworm, Spodoptera frugiperda Smith, 1797, is a polyphagous insect reported on more than 350 host plants. In Niger, Spodoptera frugiperda was first reported in 2016 and 2 years later, it was able to establish itself in all agricultural areas of the country posing a threat to crops. Surveys carried out in the various agricultural areas of Niger have revealed the presence of Spodoptera frugiperda on maize, sorghum, millet, onions and okra. Fall armyworm is an extremely voracious caterpillar on cereal crops with a preference over maize where it is considered a major pest. Its presence on sorghum and millet is a concern because these two cereals are part of the basic diet in Niger. The objective of this work is to contribute to the development of strategies for the sustainable management of Fall armyworm in Niger. To do this, trapping and damage assessment of Fall armyworm was carried out in the fields (millet, sorghum and maize) of the experimental site of the Faculty of Agronomy. Captures of adults were possible thanks to the Delta trap and the PH-869-1PR Para pheromone Spodoptera frugiperda . The largest number of male Spodoptera frugiperd a was captured in field 3 with an average of 5615 individuals and the lowest in fields 2 and 4 with 1538 and 0.769 individuals, respectively. The greatest damage was obtained in field 4 (maize), but statistical analysis showed that there are no significant differences between fields. The in vitro consumption test showed that Fall armyworm consumes more maize leaves than sorghum and millet leaves. The study shows that Spodoptera frugiperda is present at the experimental site, and the autumn caterpillar causes damage to maize, sorghum and millet. The perspective is that the knowledge of the bio-ecology of the insect will allow a better effectiveness of control strategies.