ON A COLLECTION OF BRACONIDAE FROM THREE RICE GROWING ZONES OF TAMIL NADU

Surveys were conducted to explore the braconid 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. A total of 574 braconids with 18 species under 8 subfamilies were collected. Alpha and beta diversity were computed for the three zones. The diversity indices (Simpson’s index, Shannon-Wiener index, Pielou’s index) revealed that high rainfall zone is the most diverse zone, with Cauvery delta zone being the least diverse. Macrocentrus philippinensis was the dominant braconid with a relative abundance of 19.3%. On comparing the species similarities using the Jaccard’s index in three zones taken in pairs, it was observed that 53% similarity existed between western and Cauvery delta zones, it was 44% between the high rainfall and Cauvery delta zones, and 50% as regards the high rainfall and western zones.