Arthropod diversity and community composition on wild and cultivated rice

Abstract

1 Most crop plants are grown far from their region of origin and have been significantly altered by human selection. Given the importance of biodiversity in ecosystem function, surprisingly little is known about the effect of domestication on arthropod diversity and community composition. 2 Arthropod diversity and species abundance were compared with three genotypes of cultivated rice Oryza sativa L. and two genotypes of wild rice O. rufipogon Griff. in southern Luzon, the Philippines. 3 Domestication had a small but positive effect on total arthropod diversity. Arthropod species richness was highest on the cultivar IR64 and lowest on one of the O. rufipogon genotypes, although arthropod community composition was similar across rice genotypes. 4 Total arthropod abundance and the relative abundance of guilds did not differ between wild and cultivated rice. All common herbivores, however, responded to rice domestication. Stem-boring moths and several sap-sucking herbivores benefited from domestication, although domestication reduced densities of the wolf spider Pardosa pseudoannulata Boesenberg et Strand. 5 By contrast to previous assumptions, crop domestication may not always decrease arthropod diversity. We did not detect any changes in biodiversity or community composition suggesting that rice domestication has altered the capacity of the arthropod community to regulate herbivores.