Agricultural wastes are considered as the most important biomass for anaerobic digesters due to the high energy conteni high abundance, and low costs. However, complex lignocellulosic structure limits the hydrolysis of these materials. Thus, effective lignocellulose degradation strategies are developing to enhance the hydrolysis rate. The aim of this study is to enrich microbial consortia that degrade lignocellulosic biomass from the hindgut of Pachnoda marginata larvae. Within this scope, Pachnoda marginata larvae kept on a lignocellulose rich diet for 3 weeks and then dissected. The hindgut compartment was transferred to culture bottles. Bacterial community compositions were examined by amplicon sequencing of the 16S rRNA gene on the Illumina MiSeq platform, methanogenic archaeal communities were determined by the T-RFLP method. Biogas production was increased over time and methane production was observed in all bottles. The bacterial community profile of the enrichment culture was shifted as a result of the enrichment procedure with particularly the abundance of Porphyromonadaceae (phylum: Bacteroidetes) increasing during prolonged subcultivation. The methanogenic community was dominated by Methanobrevibacter. Our results show the successful establishment of an enrichment culture from the gut system of Pachnoda marginata larvae that effectively degrades complex lignocellulose rich biomass.