Vol. 7, Issue 12, Part H (2025)

This investigation examined the association between aphids and coccinellid predators across seven legume and mustard crops cultivated during the Rabi season of 2024-2025 in the Konkan region. Seven crop varieties (cowpea, mustard, horse gram, green gram, black gram, Dolichos bean, and Lablab bean) were grown in unsprayed plots following recommended agronomic practices. Coccinellid populations were monitored at weekly intervals on tagged plants, and species identification was performed using morphological characteristics. Five distinct coccinellid species were identified: Coccinella transversalis, Cheilomenes sexmaculata, Scymnus coccivora, Brumoides suturalis, and one unidentified species. Species diversity was assessed using Simpson's Diversity Index (SDI), Shannon-Weiner Index (SWI), and Species Evenness (SE). Results demonstrated a clear pattern of species dominance related to crop architecture: Coccinella transversalis dominated erect-growing crops (85-96% relative abundance) including cowpea, green gram, black gram, and mustard, whereas Cheilomenes sexmaculata dominated sprawling legumes (92-93% relative abundance) such as Dolichos bean and Lablab bean. Green gram exhibited the highest diversity indices (SDI: 0.28; SWI: 0.412), while mustard displayed the lowest diversity despite maintaining high coccinellid populations (SDI: 0.09; SWI: 0.176), indicating that high population density does not necessarily correspond to species diversity. These findings emphasize that crop canopy structure significantly influences coccinellid species composition and distribution, and the integration of both erect and spreading legumes into cropping systems can optimize natural pest management and biological control of aphids in agroecosystems.