Parasitoid Assemblage Structure Across Decomposing Organic Substrates in Brazil: An Integrative Reanalysis of Eight Experimental Articles

: Hymenopteran parasitoids associated with Diptera developing in decomposing organic substrates constitute ecologically diverse assemblages whose structure may be influenced by substrate type, host availability, environmental context, and parasitoid life-history traits. This study conducted an integrative reanalysis of eight experimental articles from Brazil, with emphasis on independent experimental provenance and the removal of duplicated, overlapping, and non-hymenopteran records. The final comparative dataset comprised 31 parasitoid operational taxonomic units distributed among eight families and associated with ten substrate categories. Observed richness was highest in cattle dung (16 OTUs), followed by chicken feces (12 OTUs), human feces (12 OTUs), and buffalo dung (10 OTUs). Jaccard similarity was highest between cattle and buffalo dung (J = 0.625) and between bovine kidney and fish (J = 0.625), whereas fruit-associated assemblages were comparatively distinct. The identity of the dominant parasitoid frequently changed among independent experiments within the same broad substrate category, demonstrating substantial local turnover. In the multissubstrate experiment, the proportion of parasitized host pupae differed significantly among substrates (χ² = 176.15, df = 4, p < 0.0001; Cramér’s V = 0.311). Reproductive amplification also varied markedly, reaching 7.48 adults per parasitized host unit in bovine liver and 14.81 in fish. These results demonstrate that observed substrate breadth, local dominance, and reproductive amplification represent complementary but non-equivalent ecological attributes. Integrating these dimensions while controlling for dataset overlap provides a more rigorous framework for interpreting parasitoid assemblage structure and their potential role in the natural regulation of synanthropic Diptera.