Division of Entomology, Indian Agricultural Research Institute, New Delhi-110012, (India).
In India, pearl millet, Pennisetum typhoides (Burm.), or bajra is grown in about 11.0 million hectares in arid and semi-arid regions. Amongst 116 pests infesting pearl millet, about a dozen pests, viz., shoot fly, Atherigona approximata Malloch; stem borer, Chilo partellus (Swinhoe); grey weevil, Myllocerus spp.; leaf roller, Marasmia trapezalis Guen.; sugarcane leaf hopper, Pyrilla perpusilla Wlk.; fulgorid, Peregrinus maidis Ashm.; hairy caterpillars, Amsacta spp.; earhead caterpillars, Eublemma silicula Swinhoe, and Cryptoblabes gnidiella Miller; white grub, Holotrichia consanguinea Blanch.; and midge, Geromyia penniseti, pose serious problems in the field. Shoot fly caused 20–50 per cent grain loss. The white grub is a perennial problem in Rajasthan and to a certain extent in Gujarat, Maharashtra and Kamataka. The changing pest scenario has revealed the emergence of Pyrilla, cotton grey weevil and earhead caterpillars as potential pests in different bajra growing areas of the country. Small millet ragi or finger millet (Eleusine coraeana Gaertn.) is severely damaged by the pink borer, Sesamia inferens Wlk., causing plant mortality due to dead-heart formation. Other pests include jassid (Balclutha sp.) and aphids (Rhopalosiphum maidis Fitch and Hysteroneura setariae Thom.). The minor millets are mainly attacked by different shoot fly species. Panicum miliare Lam. and P. miliaceum Linn. are heavily damaged by Atherigona iniliaceae Malloch; while Paspalum scrobiculatum Linn., Echinochloa colonum Linn. and Setaria italica Beauv. by A. bituberculata Malloch, A. nudiseta Malloch and Atherigona spp., respectively. The millet grower can hardly afford costly insecticidal inputs unless the production of coarse grains is stabilised at higher levels or the situation so worsens to necessitate their use. The identification of multiple pest resistant sources, viz., MP 31, MH 420, MH 485 and MH 491 among pearl millet germplasms, has considerably eased the situation and a workable IPM has become feasible for different categories of farmers. It should include: (i) growing of relatively resistant varieties to avoid attack by different pests, (ii) the sowings should commence immediately after the onset of monsoon or latest within 10 to 15 days after the first monsoon showers to eliminate chances of shoot fly infestation in late sown kharif crop, (iii) staggered sowings in the same area are to be avoided since it results in build-up of shoot fly population, (iv) increasing the seed rate to 4 kg and later on removing and destroying affected seedlings if carried out as a regular campaign will also check the shoot fly damage, (v) in the case of heavy attack in endemic area; spraying the crop with 0.07% endosulfan can be undertaken. In water scarcity zones, dusting the crop with 4% endosulfan @ 15 kg/ha may be resorted to, (vi) in white grub endemic areas, immediately after the first showers, collection and destruction of adult beetles settling on neem and Acacia trees for mating, can be undertaken, (vii) spraying with 0.05% monocrotophos or 0.2% carbaryl on host trees, with the onset of monsoon can also be done. However, all host trees should be sprayed within 2 to 3 days after the receipt of rains, (viii) application of 10% BHC + FYM mixture (2:3) @ 100 kg/ha in furrows at the time of sowing should be quite effective, (ix) leaf feeding insects such as army worms, hairy caterpillars, grasshoppers and stem borers, etc. can be managed by adopting clean cultivation and deep ploughing after harvest of the crop so as to expose the pupae of army worms and hairy caterpillars and ‘egg pods’ of grasshoppers in soil to weathering agencies and bird predators will help in reducing infestation in the next season, (x) scraping and dusting the bunds with 10% BHC immediately after the outbreak of monsoon will check infestation, since initial infestation of the pest is restricted to grasses on bunds, and (xi) dusting the crop with 10% BHC or 4% endosulfan @ 25 kg/ha or spraying with 0.05% endosulfan is also very effective.
