Dry and Rainy Seasons Significantly Alter the Gut Microbiome Composition and Reveal a KeyEnterococcussp. (Lactobacillales: Enterococcaceae) Core Component inSpodoptera frugiperda(Lepidoptera: Noctuidae) Corn Strain From Northwestern Colombia

Abstract

Spodoptera frugiperda is a polyphagous pest of several crops of economic importance. Nowadays, the insect is broadly distributed in America and, recently, in Africa, Asia, and Australia. The species has diverged into corn and rice strains. The role of the gut microbiota in insect physiology is relevant due to its participation in crucial functions. However, knowledge of seasonal variations that alter the gut microbiome in pests is limited. Gut microbiome composition between the dry and rainy seasons was analyzed with cultured and uncultured approaches in S. frugiperda corn strain larvae collected at Northwest Colombia, as seasonal microbiome changes might fluctuate due to environmental changes. On the basis of culture-dependent methods, results show well-defined microbiota with bacterial isolates belonging to Enterococcus , Klebsiella (Enterobacteriales: Enterobacteriaceae), Enterobacter (Enterobacterales: Enterobacteriaceae), and Bacillus (Bacillales: Bacillaceae) genera. The community composition displayed a low bacterial diversity across all samples. The core community detected with uncultured methods was composed of Enterococcus , Erysipelatoclostridium (Erysipelotrichales: Erysipelotrichaceae), Rasltonia (Burkholderiales: Burkholderiaceae), and Rhizobium (Hyphomicrobiales: Rhizobiaceae) genera, and Enterobacteriaceae family members. Significant differences in microbiome diversity were observed between the two seasons. The relative abundance of Erysipelatoclostridium was high in the dry season, while in the phylotype ZOR0006 (Erysipelotrichales: Erysipelotrichaceae) and Tyzzerella (Lachnospirales: Lachnospiraceae) genus, the relative abundance was high in the rainy season. The overall low gut bacterial diversity observed in the S. frugiperda corn strain suggests a strong presence of antagonist activity as a selection factor possibly arising from the host, the dominant bacterial types, or the material ingested. Targeting the stability and predominance of this core microbiome could be an additional alternative to pest control strategies, particularly in this moth.

Dynamic changes of gut bacterial communities present in larvae of Anoplophora glabripennies collected at different developmental stages

“…Regarding the genus found in larvae, consistent with the findings in Lymantria xylina (Q. Y. Ma, Cui, et al, 2021), Helicoverpa armigera (X. S. Tang et al, 2012), Spodoptera exigua (Gao et al, 2020), Spodoptera frugiperda (Higuita Palacio et al, 2021), Enterococcus is found to be the most abundance in different larval developmental stages of A.…”

“…Regarding the genus found in larvae, consistent with the findings in Lymantria xylina (Q. Y. Ma, Cui, et al, 2021), Helicoverpa armigera (X. S. Tang et al, 2012), Spodoptera exigua (Gao et al, 2020), Spodoptera frugiperda (Higuita Palacio et al, 2021), Enterococcus is found to be the most abundance in different larval developmental stages of A. glabripennies . This could be explained by the fact that Enterococcus promote the growth and development of host insects by synthesizing vitamin B (Sabo et al, 2020), improving gut immunity (Shao et al, 2017) and degrading secondary compounds (Vilanova et al, 2016).…”

Role of Insect Gut Microbiota in Pesticide Degradation: A Review

“…The microbial population of an insect’s digestive tract comprises bacteria belonging to the phyla Firmicutes, Proteobacteria, Actinobacteria, and Bacterioidetes, all of which can impact the biology of hosts ( Paniagua Voirol et al, 2018 ; Gomes et al, 2020 ). Research on Spodoptera littoralis (Boisduval) found that the microbial community was mostly made up of Firmicutes, especially Enterococcus ( Chen et al, 2016 ; Higuita Palacio et al, 2021 ). Firmicutes are found in the digestive tracts of many lepidopteran larvae, even though the digestive tracts of larvae are suggested to be not very suitable for bacteria to live.…”

Host’s genetic background determines the outcome of reciprocal faecal transplantation on life-history traits and microbiome composition

“…Erysipelotrichaceae, which can be considered genotype-specific core taxa here, commonly occur in insect guts [ 108 ]. For example, they occur in dung beetles depending on genus and diet [ 19 ], and in Lepidoptera depending on growth environment [ 28 ] and season [ 38 ]. The family Erysipelotrichaceae consists of anaerobic or aerotolerant bacteria with fermentative metabolism [ 108 ].…”