Construction of Life-table of White grub (holotrichia spp.) under natural condition

Abstract

An investigation on "Construction of life-table of white grub (Holotrichia spp.) under natural condition" was carried out at White Grub Research Laboratory, Department of Entomology, Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, during 1st July 2015 to 15th June 2016. Three types of life tables like, age specific life table, stage specific life table and life and fertility table for female were constructed during the investigation. In age specific life table, the age specific survivorship (lx), death (dx) and life expectary (ex) was observed of H. consanguinea species. The H. consanguinea species occupied the shortest time 120 days to complete its generation, under natural condition. The highest apparent mortality was found in first ins tar larval stage was 17.77 percent on H. consanguinea, and the lowest apparent mortality was observed at pupal stage was 1.75 percent on H. consanguinea, under natural condition. The K-value is the key factor for observed the stage specific life table of H. consanguinea. The K-value was (0.2821 ), potential fecundity 24 eggs/female and net reproductive rate (8.38) was observed on H. consanguinea, under natural condition. The population growth was reported from the survival and fertility life table for female using the parameters net reproductive rate (Ro ), intrinsic rate of increase (nn), mean length of generation (T), doubling time (DT) and finite rate of increase (A.). The mean length of generation (117.91), finite rate of increase (1.0169) and doubling time (51.72) was observed on H. consanguinea, under natural condition. The result obtained from the present study, it may be concluded that H. consanguinea species of white grub is most serious insect-pest of sugarcane for western Uttar Pradesh