J. Alfred Daniel ¹, K. Ramaraju ², S. Mohan Kumar ³, P. Jeyaprakash ⁴, N. Chitra ⁵

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore - 641003, Tamil Nadu, IN
2 Director of Research, Tamil Nadu Agricultural University, Coimbatore - 641003, Tamil Nadu, IN
3 Department of Plant Biotechnology, Tamil Nadu Agricultural University, Coimbatore - 641003, Tamil Nadu, IN
4 Department of Rice, Tamil Nadu Agricultural University, Coimbatore - 641003, Tamil Nadu, IN
5 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore -641003, Tamil Nadu, IN

Abstract

For insect diversity studies to be of value, the sampling methods employed must produce samples representative of the community or taxon selected for the investigation. However, as yet, few evaluations on the variability and effectiveness of sampling methods have been undertaken. The survey was carried out in the rice fields during 2015-16 in Paddy Breeding Station, Tamil Nadu Agricultural University, Coimbatore. From this study a total of 1,019 parasitoid individuals were collected. Among six different collection methods employed for sampling hymenopteran parasitoids in rice ecosystem, the yellow pan trap at ground level was found to be the most effective method in trapping the parasitoids (27.2 ± 2.56 parasitoids per day) followed by sweep net method (12.1 ± 1.03 parasitoids per day). The next best sampling method is yellow pan trap erected at canopy level which recorded a mean of 9.2 ± 2.26 parasitoids per day. The other three traps viz., malaise trap, suction trap and light trap were found to collect less number (<1.5) of parasitoids per day.

Keywords

Efficiency, Parasitoids, Rice, Sampling, Traps.

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J. Alfred Daniel ¹, K. Ramaraju ², K. Sudheer ³, K. Vishnu ³

Affiliations
1 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore − 641003, Tamil Nadu, IN
2 Director of Research, Tamil Nadu Agricultural University, Coimbatore − 641003, Tamil Nadu, IN
3 The Zamorin’s Guruvayurappan College, Kozhikode − 673014, Kerala, IN

Abstract

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.

Keywords

Diversity, Ichneumonidae, Parasitoids, Rice Ecosystem.

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