Taxonomic identification of Valanga sp. from Cilacap, Central Java (Orthoptera: Acrididae) based on morphometric and DNA barcoding analyses

Valanga is a genera of the Orthoptera: Acrididae widely distributing across Southeast Asia and the Pacific región. In Indonesia Valanga spp. has been traditionally recognized as the dominant species, yet morphological overlap with other congeners complicates species-level identification. This study employed an integrative taxonomic approach combining morphometric analysis and COI-based DNA barcoding to identify Valanga irregularis specimens collected from Cilacap, Central Java. Specimens were collected manually and preserved in 95% ethanol for morphological and molecular analyses. Morphometric data were obtained from key body traits using digital calipers, while DNA was extracted from leg muscle tissue, amplified with universal COI primers, and sequenced using the Sanger method. Results revealed pronounced sexual size dimorphism, with females significantly larger and more variable in nearly all measured traits compared to males. Morphological features such as large body size, shorter antennae relative to body length, and distinct femoral markings were consistent with descriptions of the genus Valanga. However, BLAST analysis of COI sequences showed 99.54% similarity with V. irregularis from Queensland, Australia, rather than with V. nigricornis. Phylogenetic reconstruction using the Maximum Likelihood method (K2P model) confirmed a strongly supported monophyletic clade (>95% bootstrap) between the Cilacap specimens and V. irregularis. These findings provide the first molecular evidence of V. irregularis in Indonesia, highlighting the importance of combining morphological and molecular approaches to resolve taxonomic ambiguities. The results also expand knowledge on the potential genetic variation and distribution of Valanga spp., with implications for biodiversity monitoring and pest management in agricultural systems.