Biology subjects

Oliveira, N. C. d.

Publications and source records attributed to Oliveira, N. C. d..

3 recordsLinked to original sources

bioRxiv2023

Host plant affects the larval gut microbial communities of the generalist herbivores Helicoverpa armigera and Spodoptera frugiperda

Investigations on symbiotic associations between Lepidoptera and bacteria have been inconclusive as to whether these microorganisms represent transient or persistent associations. One reason for this is that most studies have sampled the microbiota from only a few species and frequently from laboratory-reared animals. We sequenced the 16S rRNA gene to profile the gut microbiome of the field collected, agricultural pests Helicoverpa armigera and Spodoptera frugiperda. We found that variation in the structure of bacterial communities is in great part associated with their host diet. Moreover, Enterococcus, among a few other taxa, is consistently present in all samples regardless of the plant hosts were collected. The larval gut bacteria composition matches previously published data in the same or related species, indicating that associations with bacteria taxa such as Enterococcus are persistent despite geographical variation and sampling techniques. Based on our phylogenetic analysis it is not clear, however, if Enterococci associated with Lepidoptera are necessarily different from environmental bacteria. We conclude that to fully understand the nature of Lepidoptera - gut bacteria associations it will be necessary to conduct larger sampling efforts and combine them with identification methods of bacterial strains that go beyond screening of the 16S rRNA gene.

microbiology↗

bioRxiv2022

Dysbiosis of the larval gut microbiota of Spodoptera frugiperda Strains feeding on different host-plants

The gut microbiota plays important roles in the bioecology of insects, including host plant adaptation and speciation. Spodoptera frugiperda has two well-established host-adapted strains with marked differences at the genetic and host plant utilization levels. We investigated whether differences in the gut microbiota would occur between the "corn" (CS) and "rice" (RS) strains of S. frugiperda when feeding on different crops. The gut microbiota of larvae fed on corn and millet was predominantly represented by Firmicutes followed by Proteobacteria, with an opposite pattern in larvae fed on cotton. No differences were observed between the CS and RS using PERMANOVA. PCoA analyses resulted in distinct bacterial clusters based on the host plant. Comparisons of strains gut microbiota at the phylum level resulted in differences only for larvae fed on cotton, but differences in the relative abundance of minor representatives at the genus level between strains were observed regardless of the food source used. We also found differences in the potential functional contribution of bacteria between the strains. In conclusion the gut microbiota of S. frugiperda is strongly modulated by the host plant while strains seemed to play a minor role in changing the abundance of members of the gut bacterial community.

microbiology↗

bioRxiv2021

Host-Adapted Strains of Spodoptera frugiperda Hold and Share a Core Microbial Community Across the Western Hemisphere

The fall armyworm Spodoptera frugiperda is an important polyphagous agricultural pest in the Western Hemisphere and currently invasive to countries of the Eastern Hemisphere. This species has two host-adapted strains named "rice" and "corn" strains. Our goal was to identify the occurrence of core members in the gut bacterial community of Fall armyworm larvae from distinct geographical distribution and/or host strain. We used next-generation sequencing to identify the microbial communities of S. frugiperda from corn fields in Brazil, Colombia, Mexico, Panama, Paraguay, and Peru, and rice fields from Panama. The larval gut microbiota of S. frugiperda larvae did not differ between the host strains neither was it affected by the geographical distribution of the populations investigated. Our findings provide additional support for Enterococcus and Pseudomonas as core members of the bacterial community associated with the larval gut of S. frugiperda, regardless of the site of collection or strain, suggesting that these bacteria may maintain true symbiotic relationships with the fall armyworm. Further investigations are required for a deeper understanding of the nature of this relationship.

microbiology↗