Research Publication Details

Abstract

Simplicillium and Leptobacillium are entomopathogenic fungal genera frequently associated with arthropods in tropical ecosys tems and considered promising candidates for biological pest control. However, the diversity of these genera in tropical regions, particularly in Malaysia, has not been systematically investigated in the context of their taxonomy and phylogenetic relationships. This study aimed to investigate the taxonomic diversity and phylogenetic relationship of Simplicillium and Leptobacillium using integrated morphological and molecular analyses. During a survey of entomopathogenic fungi conducted in Malaysia from 2022 2023, parasitized insects were collected, including spiders and wasps infected by entomopathogenic fungi. Phylogenetic analyses were performed using concatenated datasets of the internal transcribed spacer (ITS) and translation elongation factor 1-alpha (TEF1-α) gene to construct phylogenetic trees. The study identified one novel species, Leptobacillium geminatum sp. nov., isolated from a spider. In addition, five species are reported here as new records for Malaysia: S. formicae, L. leptobactrum. symbioticum, andL.coffeanumisolated from spiders and S. puwenense, isolated from a wasp. Morphological characteristics together with molec ular phylogenetic evidence supported the taxonomic placement of these taxa. These findings represent the first comprehensive documentation of Simplicillium and Leptobacillium species from Malaysia, significantly expanding the known diversity and geo graphical distribution of these entomopathogenic fungi in Southeast Asia.