Abstract: The non-grain cropland consolidation helps ensure food security while potentially restructuring natural enemy communities. However, differences in natural enemy community characteristics between consolidated paddy fields and conventional paddy rice systems remain unclear. In this study, arthropod natural enemies in paddy fields consolidated from orange orchards were investigated using Malaise traps and compared with conventional paddy fields in terms of natural enemy community characteristics and population dynamics. The results show that the consolidated paddy fields had a greater richness of natural enemy species, with only 13 shared species between the two field types. Both types of fields were dominated by Trathala flavo-orbitalis, Cotesia ruficrus, and Cotesia glomeratus, with Trathala flavo-orbitalis and C. glomeratus showing higher relative abundance in consolidated paddy fields. In consolidated fields, the species richness of natural enemies increased significantly with rice growth, whereas it remained relatively stable in conventional fields. During the tillering stage, species richness, Simpson diversity index, and Shannon diversity index were significantly lower in consolidated fields than in conventional fields, while the Simpson concentration index showed the opposite trend. The natural enemy communities of rice planthoppers and rice leaf folders differed between the two field types, with a community similarity coefficient lower than 0.25. In consolidated fields, the abundance of predatory natural enemies for rice planthoppers and rice leaf folders increased significantly with rice growth and was significantly higher than in conventional fields during the booting, milky and mature stages. The above results indicate that orange orchard consolidation has altered the natural enemy community. The dynamics of natural enemy diversity and the differences in dominant species reveal the potential impact of the non-grain cropland consolidation on natural enemy diversity, providing a scientific basis for ecological management in non-grain consolidation areas of rice systems.

Key words: non-grain cropland consolidation, rice fields, arthropod natural enemies, diversity, population dynamics