Seasonal incidence pattern and host preference of Odoiporus longicollis Olivier (Coleoptera: Curculionidae) in certain banana cultivars of Assam

Coleopteran insect Odoiporus longicollis Olivier is an economically important monophagous insect pest of banana. In Assam, it is a serious constraint in banana production. The present study was undertaken from May, 2015 to April, 2018 to monitor seasonal incidence of the pest in certain banana cultivars of Assam viz., Bhimkal, Kachkal, Manohar, Malbhog, Jahaji, Sapor Jahaji and Chenichampa. Survey was done in farmers’ plot at different locations of Jorhat district of Assam. All the stages of the insect was observed inside the pseudostem all round the year. The trend of incidence pattern showed correlation with meteorological parameters. The pest remains active almost throughout the year but percent infestation reached its peak during July to September, which then declined during November to January. Cultivar Bhimkal was completely infestation free while a mild infestation was seen in Kachkal (8.73, 11.56 and 10.79%) followed by cultivar Manohar (28.31, 28.5 and 24.12%), Malbhog (59.2, 49.53 and 45.67%), Jahaji (51.37, 50.52 and 44.57%), Sapor jahaji (61.36, 54.94 and 48.29%), Chenichampa (48.73, 40.53 and 45.92%) as recorded in 3 years of survey in 2015–2016, 2016–2017, 2017–2018, respectively. Therefore, cultivar Malbhog, Chenichampa, Jahaji and Sapor Jahaji are the most preferred cultivars of the pest in Assam.