Diversity of bacterial communities associated with the gut of the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Eastern India

Abstract Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) is an invasive alien pest native to the Americas, and it was introduced in the state of Karnataka, India in the year 2018. They cause severe economic damage to the maize crop, which significantly decreases the quality and quantity of the crop's yield. The microbiota of fall armyworm could play important roles in their growth, development and environmental adaptation to their host plants or animals and not much is known about the microbiota of FAW in India. Even though bacterial communities in S. frugiperda are inadequately studied, therefore, a study was undertaken on the microbial communities associated with the gut of S. frugiperda collected randomly from twelve different locations in the eastern part of India under laboratory conditions. The results revealed that the two bacterial phyla, namely, proteobacteria and firmicutes, were predominantly present in the larval gut of S. frugiperda . However, analyses at the genus level revealed that despite the high genus-level diversity between samples, there were 9 different genera observed. Interestingly, we found two bacterial genera, i.e., Kluyvera and Yokenella , which may be new findings from the eastern part of India and were not reported earlier from any other countries. On the other hand, analyses at the species level revealed that a total of thirty-three (33) species were found from the 12 samples of S. frugiperda collected from different locations. Among the 33 species, Enterococcus group genera were most abundant across the FAW gut samples collected, followed by Klebsiella sp. and Enterobacter sp . and a small proportion of Raoultella, Citrobacter, Leclercia and Pantoea.