N. Chitra ¹, K. Gunathilagaraj ², R . P. Soundararajan ²

Affiliations
1 Agricultural Research Station, Ramanathapuram 623 501, Tamil Nadu, IN
2 Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, IN

Abstract

The predatory potential of the orthopteran predators viz., Conocephalus longipennis (de Haan), C, maculatus Le Guiilou, Anaxipha longipennis Serv. and Metioche vittaticollis (Stal) against the eggs of rice insect pests was studied under laboratory conditions. M. vittaticollis proved to be an effective predator on the eggs of rice leaf folders (Cnaphalocrocis medinalis (Guenee) and Marasmia patnalis (Bradley) and rice moth, Corcyra cephalonica (Stainton), while C. longipennis and C. maculatus fed voraciously on the eggs of rice stem borer (Scirpophaga incertulas Walker) and rice earhead bug, Leptocorisa acuta (Thunberg), M. vittaticollis did not feed on stem borer eggs while C. longipennis and C. maculatus did not prefer to feed on leaf folder eggs. A. longipennis fed on all the eggs tested along with rice leaves but never on Corcyra eggs.

Keywords

Egg Predators, Orthopteran, Rice Insects.

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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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