This work deals with the taxonomic study of a bacterium, strain Tp12(T), isolated from caterpillars of the pine processionary moth (Thaumetopoea pityocampa Denis & Schiffermuller, 17 75; Lepidoptera, Thaumetopoeidae). The isolate was assigned to the genus Brevibacterium on the basis of a polyphasic taxonomic study, including morphological and biochemical characteristics, 16S rRNA gene sequence analysis, fatty acid analysis and DNA G + C content. The highest 16S rRNA gene sequence similarity to this isolate was approximately 96%, with the type strains of Brevibacterium album and Brevibacterium samyangense. Cellular fatty acids of the isolate are of the branched type, with the major components being anteiso-C-15:0 and anteiso-C-17:0. The DNA G + C content was 69.8 mol%. Although the strain was related to B. album and B. samyangense according to 16S rRNA gene sequence analysis, it differed from any known species of Brevibacterium. Based on this evidence, the novel species Brevibacterium pityocampae sp. nov. is proposed, with strain Tp12(T) (=DSM 21720(T) =NCCB 100255(T)) as the type strain.