BACKGROUND AND OBJECTIVES: Argiope modesta is an ecologically important predatory spider that contributes to natural pest suppression in agricultural ecosystems. The global agricultural system is under mounting pressure as food demand continues to rise. Meeting this demand requires increasing crop productivity while minimizing environmental impacts and preserving ecosystem integrity to support long-term sustainability. The study objectives were to investigate the phylogenetic position of A. modesta using cytochrome c oxidase subunit I sequences, estimate divergence times and identify genetically distinct lineages within and among geographic populations.METHODS: Eight specimens were collected from shrubland habitats in Kebon Bambu Village, Bekasi Regency, West Java, Indonesia. Basic local alignment search tool analysis confirmed that 97 percent of the collected individuals matched A. modesta.FINDINGS: Seven polymorphic sites were detected within the Kebon Bambu population. Phylogenetic reconstruction placed A. modesta in a clade closely related to A. aetherea. Comparison with sequences from Bali (Indonesia) and the Philippines revealed 27 polymorphic sites, indicating substantial geographic differentiation. Molecular dating suggests that the Kebon Bambu, Balinese, and Philippine populations diverged approximately 1.21 million years ago during the early Pleistocene (Calabrian stage), with the Kebon Bambu lineage undergoing subsequent independent evolutionary development during the Holocene. These results suggest potential genetic distinctiveness of the Kebon Bambu population. However, the small sample size (n = 8) from a single locality limits robust conclusions about population-level genetic diversity and lineage distinctiveness. Preservation of intraspecific genetic diversity remains critical for ecosystem resilience and biological pest control. The validated COI sequences provide a basis for long-term molecular monitoring using deoxyribonucleic acid barcoding. CONCLUSION: The study reveals significant genetic differentiation in A. modesta, with the Kebon Bambu population forming a distinct cytochrome c oxidase subunit I -based lineage defined by unique polymorphic markers. This genetic uniqueness provides a foundation for investigating potential local adaptation. However, whether such variation translates into enhanced biological control or pest suppression remains unresolved. Integrative studies combining genomics with functional phenotyping and field experiments are essential to justify conservation prioritization.
Putra et al. (Thu,) studied this question.