Indian Journal of Entomology Online published Ref. No. e22222 DoI. No.: 10.55446/IJE.2022.671 RESISTANCE TO MIRID BUG CREONTIADES BISERATENSE (DISTANT) IN COTTON Sahana K B, Shivaray navi * , vijayKumar L, ShaShi Kumar C, Sanath Kumar v B, Somu G and ChiKKaruGi n m *AICRP on Cotton, Haradanahalli Farm, Chamarajanagara 571127, Karnataka, India University of Agricultural Sciences, Bangalore 560065, Karnataka, India *Email: naviss1977@gmail.com (corresponding author) ABSTRACT A feld experiment was carried out in the AICRP on Cotton, Haradanahalli Farm, Chamarajanagar, Karnataka to know the association of morphological characters of 15 cotton genotypes (different resistance category) infuencing resistance to mirid bug, Creontiades biseratense. Cotton morphological parameters viz., trichome density on leaves, squares and midvein showed a signifcance difference with the genotypes and the higher incidence of mirid bug was recorded on genotypes having more trichome density. Similarly, genotypes having higher boll rind thickness and length of petiole recorded the higher incidence. of C. biseratense. There was a signifcant positive correlation between C. biseratense incidence and trichomes on leaves (r = 0.90**), trichomes on squares (r = 0.89**), trichomes on midvein (r = 0.91**), boll rind thickness (0.80**) and length of petiole (r = 0.60*). However thickness of leaf showed the non-signifcant negative difference among the genotypes (r = -0.03). Key words: Cotton, resistance, incidence, screening, Creontiades biseratense, trichome density, midvein, boll rind, thickness of leaf, squares, length of petiole, correlation coeffcient Cotton is one of the most commercially grown fbre crop in the world, plays a pivotal role in economic and social affairs of the world. In India cotton is most important cash crop accounting for 65 % (CCI, 2021) of the textile industry’s fbre and handloom cloth quality has been widely praised in the market for its fneness and comfort. It occupies a signifcant position in the Indian national economy as it provides livelihood to millions of people so it is one of the major foreign exchange earners of the country. India has the world’s largest cotton cultivation area, accounting for around 41% of global cotton area and providing 21% of total cotton production, increasing from 12.50 million hectares to 13.00 million hectares. (CCI, 2021). Thus, India ranks frst in cotton area and production by cultivating in an area of 132.85 lakh hectares with a production of 352.48 lakh bales and productivity of 451 kg/ ha during 2020- 21 (CCI, 2021). Among the many constraints in cotton production, insects are becoming a major one. About 1326 species of insect pests are known to attack the cotton crop across the world at different growth stages of the crop. In recent days sucking pests are causing severe menace in cotton ecosystem (Hanchinal et al., 2009; Meghana et al., 2018). In South India, the mirid bug, Creontiades biseratense (Distant) was newly recorded and creating a major problem in Bt cotton that leading to signifcant yield loss in cotton cultivation (Patil et al., 2006). Among sucking pests, the mirid bugs are observed to be the serious pest of Bt cotton (Sahu and Samal, 2020) and their survey on incidence in Bt cotton carried out in Karnataka with varied level of climatic factors (Vinayaka and Nandihalli, 2019). Hence, identifcation of mirid bug tolerant and high yielding genotypes need to be identifed. To develop the resistant or tolerate cultivar against the pest, studying the host plant resistance mechanism is crucial. Therefore present investigation of morphological association of resistance against mirid bug was conducted during 2020-21. MATERIALS AND METHODS To establish the resistance and susceptibility in relation to incidence of mirid bugs and major plant morphological characters in cotton, the observations on length of petiole, thickness of leaf and bolls, trichome density on leaves and square, density of trichome on midvein were made by adopting standard procedures by selecting 15 genotypes viz., Br-24b-2676, Br-24b-2673, Br-24b-2675, Br-24b-2671, Br-2b-373, Br-2b-375, Br-24b-2678, CET H×B 20608, Br-2b-378, CET H×B 20609, CET H×B 20606, Br-13a-2663, CET H×B 20605, Br-2b-358 and Br-2b-359 representing different level of incidence at 60 DAS from screening trial of Kharif 2020.The observation on mirid bug was made from 10 squares/ plant from ten randomly selected plants. The mean data on the plant morphological