Biology and Seasonal incidence of pseudostem weevil, Odoiporus longicollis Olivier (Coleoptera: Curculionidae) in banana

In order to study the biology and seasonal incidence of banana pseudostem weevil, Odoiporus longicollis Olivier, laboratory as well as field experiments were conducted during 2012-13.The incubation period varied from 3 - 4 (mean 3.6 – 0.54) days. The grub passed through five instars to complete the larval period. The total larval period varied from 30 to 35 (Mean 32.2 – 1.92) days. The pre pupal period lasted for 3 to 5 (mean 4.1 – 0.89 ) days. The pupal period lasted for 17 to 20 (mean 18.6 – 1.34) days. The total life cycle of O. longicollis from egg to adult emergence varied from 53.0 to 65.0 (mean 58.4 – 4.39) days. The adult individuals reared in the laboratory survived for 65 to 80 (mean 74.2 – 6.87) days. The incidence of pseudostem weevil on banana commenced from February and continued its activity till the month of December 2012 and the maximum number of population (12.76 insects per plant) was recorded during second fortnight of August 2012. The number of holes was observed maximum (14.87 per plant) during second fortnight of August. All the weather parameters except relative humidity at 07 hrs and 14 hrs. had significant impact on weevil population and number of holes on pseudostem. All these weather parameters together produced 89.0 and 89.2 per cent impact on weevil population and number of holes produced, respectively.