SEX-DEPENDENT METAGENOMIC INSIGHTS INTO THE ENDOSYMBIOTIC BACTERIAL ECOLOGY OF ZYGOGRAMMA BICOLORATA PALLISTER (COLEOPTERA: CHRYSOMELIDAE)

Abstract

Insects are among the most ecologically successful animal taxa and are known to harbour diverse endosymbiotic microorganisms, including bacteria, viruses, fungi, and protozoa, which can influence various aspects of host biology. This study investigates the bacterial endosymbiont communities associated with the parthenium beetle (Zygogramma bicolorata Pallister), a biocontrol agent for a weed, Parthenium hysterophorus. We hypothesized that Z. bicolorata harbours a diverse microbiota that may contribute to sex-specific physiological or ecological functions. Male and female beetles were subjected to 16S rRNA gene amplicon sequencing using the Illumina MiSeq platform. Taxonomic profiling revealed notable differences in bacterial community composition between the sexes. Males were dominated by Proteobacteria (67.17%), followed by Firmicutes (15.26%), Cyanobacteria (6.39%), Bacteroidetes (6.30%), and Actinobacteria (4.14%). In contrast, females exhibited a marked predominance of Firmicutes (57.53%), with comparatively lower proportions of other phyla. These findings indicate that Z. bicolorata harbours a diverse and sex dependent bacterial community, suggesting potential functional roles of endosymbionts in host development, physiology, or ecological adaptation.