Platygastroidea from rice ecosystems of Tamil Nadu

Surveys were conducted to explore the Platygastroidea fauna in rice ecosystems of Tamil Nadu during 2015-16 in three different rice growing zones viz., western zone, Cauvery delta zone and high rainfall zone. These resulted in collection of 731 individuals representing two families, four subfamilies, 15 genera and 22 species. Alpha and beta diversity were computed for the three zones and the diversity indices (Simpson’s index, Shannon-Wiener index, Pielou’s index) revealed that high rainfall zone is the most diverse, while Cauvery delta zone being the least. Fourteen species were collected from western zone ranks first in species richness. Gryon sp. nr. clavigralla was the predominant platygastroid in the rice ecosystem with a relative abundance of 15.2%. Comparison of species similarities between the zones revealed 28% similarity between western zone and high rainfall zone; 43% similarity between Cauvery delta zone and high rainfall zone; and 26% between western zone and Cauvery delta zone.