Microbial diversity in the Pale tussock moth, Calliteara pudibunda L., 1758 (Lepidoptera: Erebidae) larvae in the Eastern beech forest in Türkiye

The Pale tussock moth, Calliteara pudibunda L., 1758 (Lepidoptera: Erebidae) is an important defoliator of deciduous forests, particularly Fagus orientalis Lipsky (Fagales: Fagaceae), with recurrent outbreaks in Türkiye. Despite its ecological and economic importance, its microbial communities remain poorly characterized. In this study, the microbiome of larvae collected during an outbreak in Bursa was analyzed by shotgun metatranscriptomic sequencing in Trabzon between 2023 and 2024. A total of 53.4 million paired-end reads were generated and taxonomically classified using Kraken2. The microbiome was dominated by Firmicutes and Proteobacteria, comprising more than 65% of bacterial reads, while Reoviridae and Baculoviridae were the most abundant viral families. Sequences related to Cypovirus 15 and Orgyia pseudotsugata multiple nucleopolyhedrovirus (OpMNPV) were detected. Electron microscopy further confirmed the presence of two baculoviruses, Calliteara pudibunda nucleopolyhedrovirus-Türkiye (CapuNPV-T1) and Calliteara pudibunda granulovirus-Türkiye (CapuGV-T). Archaeal sequences included extremophiles such as Sulfolobus acidocaldarius A (Sulfolobales: Sulfolobaceae) and methanogenic Methanosarcina spp. Kluyver & van Niel (Methanosarcinales: Methanosarcinaceae). These findings provide the first high-resolution insights into the microbiome and virome of C. pudibunda in Türkiye, highlighting microbial associations relevant to biological control strategies.