Ichneumonid fauna associated with rice ecosystems of Tamil Nadu, India

Surveys were conducted to explore the Ichneumonid 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. Totally 604 Ichneumonid individuals were collected from rice ecosystem in the present study. These 604 individuals represent 14 subfamilies, 24 genera and 33 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 western zone as the most diverse zone, while Cauvery delta zone being the least diverse. Leptobatopsis indica was the dominant Ichneumonid species in the rice ecosystem with a relative abundance of 8.1%. On comparing the species similarities using the Jaccard’s index among the three zones taken in pairs, it was found that 12 per cent similarity between Western and Cauvery delta zones and no similarity between high rainfall and Cauvery delta zones and 25 per cent similarity between high rainfall and western zones.