Badal Bhattacharyya ¹, A. A. L. H. Baruah ¹, Purnimadas ¹, U. Bhuyan ¹

Affiliations
1 AINP on White grubs and other Soil Arthropods, Department of Entomology, Assam Agricultural University, Jorhat- 785013, Assam, IN

Abstract

In the present study, efforts were made to explore the possibility of using Beauveria bassiana and Metarhizium anisopliae aione or in combination with different insecticides for the management of white grubs in green gram. B. bassiana formulation applied @ 5×10¹³ conidia ml⁻¹ in combination with imidacloprid 200SL at 48g a.i. ha⁻¹ was found to be effective exhibiting lowest plant mortality (1.66%) and lowest grub population (1.60/pit), which resulted in highest yield of 6,83q ha⁻¹. Likewise M. anisopliae when applied @ 5×10¹³ conidia ml⁻¹ in combination with imidacloprid 200SL at 48g a.i. ha^-1 resulted in lowest plant mortality (2.28%) and grub population (1.12/pit) and highest yield of 6.79q ha^-1.

Keywords

Beauveria bassiana, Green Gram, Metarhizium anisopliae, White Grub.

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Badal Bhattacharyya ¹, R.D. Gautam ²

Affiliations
1 Department of Entomology, Assam Agricultural University. Jorhat-785013 (Assam), IN
2 Division of Entomology, Indian Agricultural Research Institute, New Delhi, 110012, IN

Abstract

The dispersal of ³²P labelled population of Trichgramma chilonis in rice crop was studied during kharif 2002 and 2003. In the experiments in kharif 2002, radioactivity on the rice leaf folder eggs was detected for a distance of 9-12 metre in southern direction (downwind sector). However, at North (upwind sector), the radioactivity could be detected for up to 3-6 metre range. Likewise, the data on radioactivity of the leaf folder eggs in all four directions clearly indicated that the labelled parasitoids moved more or less evenly for up to a distance of 6-9 metre from the release point during kharif, 2003.

Keywords

Dispersal, Radio-labelling, Rice Leaf Folder, Trichogramma chilonis, ³²P.

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Saurabh Sarma ¹, D. K. Saikia ¹, Badal Bhattacharyya ¹, S. K. Dutta ¹

Affiliations
1 Department of Entomology, Assam Agricultural University, Jorhat - 785013, Assam, IN

Abstract

The seasonal incidence of sugarcane woolly aphid, Ceratovacuna lanigera Zehntner (Homoptera: Aphididae), and its natural enemies was studied at Instructional-Cum-Research (ICR) Farm, Assam Agricultural University (AAU), Jorhat and at Sugarcane Research Station (SRS), Buralikson, Golaghat during 2004-05. Out of five species of natural enemies recorded at ICR Farm, AAU, Jorhat, Eupeodes confrater (Wiedemann), Chrysoperla carnea (Stephens), Coelophora biplagiata (Mulsant) and Dipha aphidivora (Meyrick) had significant positive impact on sugarcane woolly aphid population, while non-significant negative correlation of aphid population was observed with the population of Encarsia flavoscutellum Zehntner. Multiple regression analysis of different natural enemies with the population of C. lanigera showed 89.0 per cent relationship with the aphid population. At SRS, Buralikson, Golaghat, the only observed natural enemy D. aphidivora showed significant positive impact on woolly aphid population.

Keywords

Ceratovacuna lanigera, Encarsia flavoscutellum, Population Build Up, Predators, Sugarcane.

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