Survey Surveillance and Management of Mirid Bug and Flower Bud Maggot in Bt Cotton

Abstract

newlineSurvey, surveillance and management of mirid bug Poppiocapsidea biseratense newline(Distant) and flower bud maggot, Dasineura gossypii Flecher in Bt cotton were carried newlineout at Main Agricultural Research Station (MARS), University of Agricultural newlineSciences, Dharwad during kharif 2016-17 and 2017-18. The mirid bug and flower bud newlinemaggot populations with their damages were highest in Haveri district followed by newlineDharwad and Shivamogga districts. The populations of mirid bug and flower bud newlinemaggot started from 36th MSW and 38th MSW and reached the peaks at 46th MSW and newline45th MSW, respectively. newlineFragments of cytochrome oxidase subunit I (COI) gene, partial cds; newlinemitochondrial sequences of six districts of flower bud maggots confirmed as Dasineura newlinegossypii. newlineAmong the twenty genotypes screened, Soumya and Yuva 7215-2 were newlinemoderately tolerant whereas Kanaka MRC-7351 was highly susceptible genotype for newlineboth the pests. None of the genotypes was tolerant to these pests. All the morphoanatomical newlineand biochemicals parameters studied influenced the mirid bug and flower newlinebud maggot to an extent of 89.40 and 57.40 per cent, respectively. newlineThiamethoxam at 0.25g/l was significantly superior in reducing mirid bug newlinepopulation and damage with highest yield and economical followed by combination of newlineprofenophos at 2ml/l + dichlorvos at 0.5ml/l, fipronil at 1ml/l, chlorfenapyr at newline0.5ml/l and profenophos at 2ml/l. Whereas, chlorfenapyr at 0.5ml/l showed significant newlinesuperiority against flower bud maggot with highest yield and economical followed by newlinedichlorvos at 0.5ml/l, combination of profenophos at 2ml/l + dichlorvos at 0.5ml/l, newlineprofenophos at 2 ml/l, diafenthiuron at 1g/l and fipronil at 1ml/l. newlineAmong nine spray schedules evaluated against mirid bug and flower bud newlinemaggot, the treatment with four sprays at 75, 90, 105 and 120 days was significantly newlinesuperior and economical followed by the treatment with three sprays skipping spray at newline120 days and the treatment with three sprays skipping spray at 90 days.