Gut bacterial diversity in different life stages of Fall Armyworm, Spodoptera frugiperda(Lepidoptera: Noctuidae)

The fall armyworm is an important polyphagous insect that causes widespread
damage to many crops, including maize, rice, and sorghum. It poses a major threat to food
security in several developing countries due to its rapid spread. Chemical insecticides are
used as the main management strategy to control fall armyworms in many parts of the world.
However, there have been reports of insecticide resistance developing. Hence, it requires
some green control methods to prevent and control fall armyworm populations. Fall
armyworm, like other insects, is associated with various microbiota in their different life
stages that influence their several characteristics and activities. It is found that the
manipulations of gut microbiota are considered as desirable options for fall armyworm
management. The Spodoptera frugiperda gut microbiota is generally different from
microorganisms in the external environment, including ingested food. It can promote insect
fitness by contributing to nutrition, especially by providing essential amino acids, vitamins,
etc. It also protects insect hosts against pathogens, parasitoids, and predators by synthesizing
specific toxins or modifying the insect immune system. However, so far, the function of gut
microbiota in Spodoptera frugiperda remains to be investigated. But, the research hindrance
has been overcome with the development of modern approaches such as high-throughput
sequencing of the 16S rRNA gene and meta-genome analysis. Keeping all of the above into
consideration, this review paper was written to study the structure, evolution, composition,
gut microbiota diversity, and microbiome-host interactions, as well as some important
approaches to study microbiome-host interactions and the major roles of fall armyworm gut
microbiota.