Investigations were conducted during 2015-2016, in major jasmine growing districts of Tamil Nadu, for assessing the distribution, infestation level and the relative importance of the major pests of jasmine viz., blossom midge, Contarinia maculipennis, budworm, Hendecasis duplifascialis, leaf webworm, Nausinea geometralis and two spotted mite of jasmine, Tetranychus urticae. Majority of respondents were aware of the major jasmine pests, among which 53 per cent respondents ranked budworm as the most important pest, 16 per cent as blossom midge, 9 per cent as two spotted mite and 7 per cent as leaf webworm as major pest. The incidence of major pests of jasmine viz., blossom midge, budworm, leaf web worm and two spotted mite were observed in all the surveyed districts of Tamil Nadu in varying intensity. The incidence of these pests was higher in Madurai district recording 34.27, 35.18, and 28.75 per cent of midges, budworm, leaf webworm and 10.25 two spotted mites per 2 cm2 leaf area, followed by Tirunelveli district recording 33.19, 31.35 and 25.36 per cent incidence of midge, budworm, leaf webworm and 9.47 two spotted mites per 2 cm2 of leaf area. Regarding the temporal incidence of the major jasmine pests, jasmine growers perceived the maximum incidence from May – August for budworm/mites and September-November for midges/leaf webworm. The least incidence was from February-April. Cultural control measures like pruning of bushes and field sanitation was followed by majority of jasmine growers, thus recorded lower technology gap index (TGI) of 9 and 14 per cent. Other cultural practices like collection and destruction of fallen and discoloured buds/flowers, setting of light traps, setting of yellow sticky traps, regular weeding, regular tilling or raking of soil to destroy pupae, non-planting of alternate hosts around main cropped area, planting inter/border crops recorded maximum TGI of 82, 73, 79, 59, 85 and 87 per cent respectively indicating their unawareness. Regarding the usage of bio-control agents, only 8 per cent respondent’s attempted Chrysoperla eggs which is a common natural enemy for all major jasmine pests with a TGI of 92 per cent. Usage of entomopathogenic fungi, Metarrhizium anisopliae for midges, Beauveria bassiana for lepidopterans and mites, Hirsutella thompsonii for mites recorded higher TGI of 90, 87 and 90 per cent projecting the unawareness of the growers. Bacterial biopesticide, Bt was used by only 16 per cent respondents and Trichogramma egg cards was used by only 14 per cent respondents recording higher TGI of 84 and 86 per cent. With regard to the use of synthetic chemical insecticides/acaricides, respondents recorded medium TGI showing their awareness but the right frequency in application of chemical pesticides recorded very high TGI of 91 per cent showing the indiscriminate usage of chemicals in jasmine ecosystem. Thus, efforts should be taken to create awareness among jasmine growers for the use of eco-friendly bio-control methods against major pests of jasmine.
I. Merlin Kamala
Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore -641003 Tamil Nadu, India.
I. Isaac Devanand
Department of Agricultural Extension, Annamalai University, Chidambaram-608001, Tamil Nadu, India.
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