Ambient temperature‐mediated enzymic activities and intestinal microflora in Lymantria dispar larvae

Abstract

To understand how ambient temperature affect the gypsy moth larvae, and provide a theoretical basis for pest control in different environments. Fourth instar gypsy moth larvae were incubating for 3 hr at 15℃, 20℃, 25℃, 30℃, 35℃, and 40℃, respectively. Afterward, digestive and antioxidant enzyme activities, total antioxidant capacity, and intestinal microflora community were analyzed to reveal how the caterpillars respond to ambient temperature stress. Results showed that both digestive and antioxidant enzymes were regulated by the ambient temperature. The optimum incubation temperatures of protease, amylase, trehalase, and lipase in gypsy moth larvae were 30℃, 25℃, and 20℃, respectively. When the incubation temperature was deviated optimum temperatures, digestive enzyme activities would be downregulated depending on the extent of temperature stress. In addition, glutathione S‐transferase, peroxidase, catalase, and polyphenol oxidase would be activated under a sufferable temperature stress, but superoxide dismutase and carboxylesterase (CarE) would be inhibited. In addition, results showed that the top two abundant phyla were Proteobacteria and Firmicutes. The phylum Firmicutes abundance was decreased and phylum Proteobacteria abundance was increased by ambient temperature stress. Moreover, it suggested that gypsy moth caterpillars at different ambient temperature mainly differed from each other by Escherichia‐Shigella and Bifidobacterium in control, Acinetobacter in T15, and Lactobacillus in T40, respectively.

Stable composition of gut microbiome in the Asian ladybeetle Coccinella septempunctata reared on natural and artificial diets

“…Proteobacteria is associated with diverse metabolisms such as decomposition, fermentation of complex sugars, and the production of vitamins and degraded aromatic compounds, boosting their hosts' absorption of nutrients 49 . Previous study show that Proteobacteria dominate the gut microbiome of Gypsy moths 50 , Bombyx 51 and cotton bollworms 52 , similar findings also have been reported in many other species of insects in the family Cerambycidae 53 , 54 . The aforementioned studies suggested that Proteobacteria are widely found in gut microbiota of insects and the dominant role of Proteobacteria in the insect gut microbiota may be a distinctive feature of insect gut microbiota composition.…”

Midgut bacterial diversity of a leaf-mining beetle, Dactylispa xanthospila (Gestro) (Coleoptera: Chrysomelidae: Cassidinae)

“…Gut microbiota of 218 insect species in 21 orders are generally dominated by Firmicutes (62.1%) and Proteobacteria (20.7%) ( Yun et al 2014 ). For example, Proteobacteria and Firmicutes are amongst the dominant flora in the intestinal tract of lepidopteran insects, such as Plutella xylostella , Lymantria dispar , Helicoverpa armigera, Spodoptera littoralis, Ectropis obliqua , E. grisescens and Bombyx Mori （ Rajan et al 2020 , Shinde et al 2019 , Xia et al 2017 , Zeng et al 2019 , Chen et al 2016 , Wang et al 2020 ). Proteobacteria and Firmicutes are also dominant in the intestinal bacterial community of other insects, such as Bactrocera tau , Ceratitis capitata , Procecidochares utilis and Lutzomyia longipalpis of Diptera , Anophora glabripennis of Coleoptera and Schistocerca gregaria of Orthoptera ( Behar et al 2008b , Dillon et al 2010 , Gouveia et al 2008 , Prabhakar et al 2013 , Schloss et al 2006 ).…”

Diel pattern in the structure and function of the gut microbial community inLymantria dispar asiatica(Lepidoptera: Lymantriidae) larvae

“…Finally, three replicates were evaluated by gut microbial 16S rDNA sequencing. Procedures from DNA extraction to Illumina MiSeq sequencing were performed following our previously described methods (Zeng, Shi, Shi, et al, 2019). Sequencing was performed by MajorBio (Shanghai, China).…”

“…We have previously documented that the gut microbial community in Lymantria dispar asiatic is regulated by environmental temperature (Zeng, Shi, Guo, et al, 2019), dietary pH (Zeng, Shi, Shi, et al, 2019), and avermectin stress (Zeng et al, 2020). Previous studies have suggested that gut microbial communities in insects contribute to various biological processes, including pheromone production, pesticide degradation, vitamin synthesis, and pathogen prevention (Reeson et al, 2003).…”