Spider webs as reservoirs of culturable fungal diversity: evidence from orb-weaving Cyclosa mulmeinensis spider in Thai rice agroecosystems

Spider webs are increasingly recognised as passive environmental collectors; however, fungi remain amongst the least explored biological components associated with spider silk, particularly when examined using culture-based and taxonomically resolved approaches. In this study, we present a proof-of-concept investigation of culturable fungal diversity associated with two-dimensional, debris-decorated orb webs, constructed by the orb-weaving spider Cyclosa mulmeinensis in rice agroecosystems in Thailand. Using a standardised field-to-laboratory isolation workflow combined with genus-appropriate multilocus phylogenetic analyses, decorated orb webs were sampled as individual units from rice agroecosystems in Thailand and fungi were isolated via dilution plating on potato dextrose agar supplemented with chloramphenicol. A total of 112 fungal isolates were recovered, grouped into 45 colony morphotypes and resolved into 23 taxa across six genera: Alternaria , Aspergillus , Cladosporium , Fusarium , Penicillium and Talaromyces . Taxonomic placement was inferred primarily from multilocus phylogenetic analyses, with morphological characteristics used as supporting evidence. Notably, several isolates formed well-supported lineages within Cladosporium and Talaromyces that could not be assigned to any described species, indicating the presence of potentially undescribed taxa. These findings demonstrate that spider webs can serve as a low-impact, non-destructive substrate for accessing viable fungal diversity in agricultural ecosystems. This approach enables reproducible culture-based recovery of taxonomically informative fungal lineages and highlights the potential of spider web sampling as a complementary tool for biodiversity assessment and environmental monitoring.