Aims: Spodoptera exigua is a serious pest of many agricultural crops. However, the bacterial communities of S. exigua are poorly studied, particularly over their entire life cycle. We aimed to study the biodiversity of the microbiota across the life cycle of S. exigua and to provide a better and obtain insight into new pest control strategies. Methods and Results: The bacterial diversity across the life cycle of S. exigua was studied using Illumina MiSeq sequencing of 16S rRNA genes. Spodoptera exigua is dominated by Proteobacteria and Firmicutes, with a total relative abundance of 90Á03%. Enterococcus (24Á6%), Pseudomonas (12Á2%) and Asaia (45Á9%) were abundant and active in eggs, while Methylobacterium (18Á7%) and Halomonas (16Á5%) dominated freshly eclosed larvae. The 3rd and 5th instar larvae were dominated by Enterococcus (76Á3 and 62Á0%). Pupal stages had the highest microbial diversity. There was no significant difference between newly emerged males and females. Symbionts of eggs were extremely similar and probably vertically transmitted by males during mating. Conclusions: The result showed that the bacterial community was affected by the host developmental stages. Our results also suggest that symbionts of egg mass are probably vertically transmitted control by male spawning adults. Significance and Impact of the Study: Our study documents the symbiont bacteria across the life cycle of S. exigua. Understanding the microbial symbionts may provide clues to develop potential biocontrol techniques against this pest.

To use, maintain and increase crop germplasm collections efficiently, it is important to assess the diversity of these collections. In this study, 1383 accessions of Chinese spring sowing soybean (Glycine max) were used for SSR analysis. In total, 1111 alleles were detected among these collections with an average number of alleles (NA) of 18.52 per locus. The genetic diversity index (PIC value) varied from 0.456 to 0.928 with an average of 0.815. Intensive breeding of cultivars have led to a decrease of genetic diversity. Random-repeated sampling within landraces of different geographical regions suggested that the ranking of both average NA and PIC values among different geographical regions were North spring soybean (Nsp) > South spring soybean (Ssp) > Northeast spring soybean (NEsp), but because of the uneven distribution of SSR variation patterns, the differences between them did not reach a significant level. There was a relationship between genetic distances and geographical distances among soybean populations from different regions, indicating a certain degree of geographical differentiation among Chinese soybean germplasm collections.

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