The bacterial and fungal communities of the larval midgut of Spodoptera frugiperda (Lepidoptera: Noctuidae) varied by feeding on two cruciferous vegetables

Abstract

Spodoptera frugiperda is a highly polyphagous pest worldwide with a wide host range that causes serious losses to many economically important crops. Recently, insect-microbe associations have become a hot spot in current entomology research, and the midgut microbiome of S. frugiperda has been investigated, while the effects of cruciferous vegetables remain unknown. In this study, the growth of S. frugiperda larvae fed on an artificial diet, Brassica campestris and Brassica oleracea for 7 days was analyzed. Besides, the microbial community and functional prediction analyses of the larval midguts of S. frugiperda fed with different diets were performed by high-throughput sequencing. Our results showed that B. oleracea inhibited the growth of S. frugiperda larvae. The larval midgut microbial community composition and structure were significantly affected by different diets. Linear discriminant analysis effect size (LEfSe) suggested 20 bacterial genera and 2 fungal genera contributed to different gut microbial community structures. The functional classification of the midgut microbiome analyzed by PICRUSt and FUNGuild showed that the most COG function categories of midgut bacterial function were changed by B. oleracea, while the guilds of fungal function were altered by B. campestris significantly. These results showed that the diversity and structure of the S. frugiperda midgut microbial community were affected by cruciferous vegetable feeding. Our study provided a preliminary understanding of the role of midgut microbes in S. frugiperda larvae in response to cruciferous vegetables.

Comparative analysis of Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae) corn and rice strains microbiota revealed minor changes across life cycle and strain endosymbiont association

“…FAW microbiota diversity is greater in field-collected samples compared to laboratory samples ( Mason et al, 2020 ; Xu et al, 2022 ; Jeon et al, 2023 ; Han et al, 2023 ; Zheng et al, 2023 ). The diet is a critical factor in modifying the composition and structure of the microbial community of FAW larvae ( Yuning et al, 2022 ; Wang et al, 2023 ). In fact, FAW gut microbiota increases from gamma-irradiated leaves and an artificial diet to greenhouses corn leaves and field leaves ( Mason et al, 2020 ).…”

Impact of gut microbiota composition on black cutworm, Agrotis ipsilon (hufnagel) metabolic indices and pesticide degradation

“…In the realm of insect-microbe symbiosis, a captivating interplay unfolds as insects and their microbial partners establish dynamic relationships through coevolution. Insects offer stable habitats and essential nutrients, while microbes reciprocate with defensive strategies and nutritional support [ 104 ]. This collaboration is especially crucial in addressing insect pests, known for their ability to metabolize toxins and explore alternate nutrients.…”

Impact of intraspecific variation in insect microbiomes on host phenotype and evolution

“…When insect microbiomes shift, the environment is a dominant source of the microbes that are acquired. Diet (food as an external environmental factor) is often mentioned as one of the main factors that influence the diversity of insect microbiomes, especially among herbivorous [ 8 , 9 ] and carnivorous insect taxa [ 26 ]. The diet of an insect can act as a source of novel microbes when they are ingested with the food [ 27 ], but nutritional properties of the food can also influence an insect’s microbiome via its effect on the already existing microbes [ 28 ].…”

“…Host species and diet/trophy appear to be the most relevant drivers, but sex, life stage, and sample origin/habitat also have some impact, while the abundance of endosymbionts and phylogeny only have weak influence [ 2 – 6 ]. Intraspecific microbiome variation can be driven by several factors, such as the host itself, the diet, and the environment [ 7 – 9 ]. Microbe transmission routes, recruitment, maintenance, and interactions further shape these variations [ 10 – 12 ].…”