Dynamics of bacterial communities across developmental stages of the litchi stink bug, Tessaratoma javanica

Abstract

The Litchi stink bug, Tessaratoma javanica (Thunberg) (Hemiptera: Tessaratomidae), is a major insect pest of litchi in India. Insect-associated bacteria play significant roles in their growth and development. We studied the bacterial communities linked to T. javanica using 16 S rRNA amplicon sequencing and predicted the functions of associated bacterial communities. The findings revealed that bacterial communities significantly differ across the developmental stages of T. javanica. The primary bacterial phyla across all developmental stages linked to T. javanica were Proteobacteria, Firmicutes, Bacteroidota, Actinobacteria, Patescibacteria, and Nitrospirota. Class Gammaproteobacteria predominated in first and 4th nymphal instars, and adult females, whereas Bacilli dominated the gut of the 3rd, and 5th nymphal instars of T. javanica. Ligilactobacillus apodemi, Staphylococcus xylosus, and Pseudomonas furukawaii were identified as the predominant bacterial species associated with T. javanica. The peak bacterial diversity was observed in the 5th nymphal instar and the lowest in the 1st nymphal instar. The observed changes between growth and developmental stages indicate that bacterial communities are dynamic and perpetually developing to meet the metabolic functions of T. javanica. Comprehending these interactions will improve our understanding of the ecological relationship with this pest and assists in developing and implementing efficient biological control plans for its management.

Keywords: 16S rRNA amplicon sequencing; Bacterial microbiota; Diversity; Litchi stink bug.

Fig. 1

A UPGMA clustering and heatmaps showing the relative abundance of 16 S rRNA gene amplicon sequence variants (ASVs) between different developmental stages. The colors indicate relative abundance ranging from green (lower abundance) to red (higher abundance) (indicated on a scale of 0 to 8).

Fig. 2

Relative abundance of bacterial diversity at phylum level across different developmental stages of litchi stink bug, T. javanica. Taxa with (*) marks are statistically differed among different developmental stages (Kruskal-Wallis test; p ≤ 0.05).

Fig. 3

Principal coordinate analysis (PCoA) plot visualizes the beta diversity based on the Bray-Curtis dissimilarity index among developmental stages of the litchi stink bug, T. javanica (ANOSIM, R = 0.92, p < 0.001). Ellipses indicate clusters of developmental stages which are classified based on principal component analysis (PCA) score.

Fig. 4

LEfSe analysis (A) to identify and characterize bacterial communities from phylum to genus level associated with developmental stages of the litchi stink bug, T. javanica. Red nodes indicate no significant difference. The nodes with different colours denote that the bacterial community significantly increased at different developmental stages. LDA (Linear discriminate analysis) (B) score was greater than 2 in most bacterial taxa and indicated family-level diversity in bacterial communities across developmental stages of T. javanica.

Fig. 5

Functional prediction on KEGG ORTHOLOGY analysis of bacteria associated with adult females compared with other developmental stages of litchi stink bug, T. javanica with p-value < 0.05.

Fig. 6

Bipartite (A) networks illustrate the relationships across 20 dominated bacterial genera associated with different developmental stages of the litchi stink bug, Tessaratoma javanica (Photos were taken from ICAR-National Research Centre on Litchi orchard, Muzaffarpur, Bihar, India). The upper nodes (colour) denote the developmental stages of T. javanica while the lower node (black) denotes the bacterial genera. The length and width of each node are scaled to the total number of interactions for each developmental stage. Modular bipartite (B) matrix of identified modules based on the bipartite network analysis of shared bacterial genera among different developmental stages of T. javanica. The intensity of the blue colour in each box indicates the number of interactions identified between the modules.