Abstract The Eucalyptus plantation industry in Indonesia has expanded rapidly during the last few decades. This growth is primarily attributed to the replacement of Acacia mangium , that was severely damaged by diseases. The rapid shift to large-scale monoculture plantations of Eucalyptus has introduced new challenges, particularly the emergence of new disease and pest problems. During routine Eucalyptus disease surveys in Indonesia, symptoms of a new leaf and shoot disease were observed on a single hybrid Eucalyptus grandis × pellita clone in Riau and Kalimantan. Leaf samples were collected, and isolations were made from the disease symptoms. Isolates were identified based on their morphological characteristics and DNA sequence data for seven loci. Phylogenetic analyses of the isolates revealed a novel species of Pseudoteratosphaeria , described here as Pseudoteratosphaeria supramediana sp. nov. A greenhouse pathogenicity test resulted in symptoms similar to those found under field conditions, and the inoculated fungus was consistently reisolated from the resulting lesions. Its appearance in two geographically distinct locations of Indonesia raises the possibility of multiple independent introductions of the pathogen.
Pham et al. (2026) studied this question.