Application of New Software Programmes: Life Table of Creatonotus gangis on Artificial diet

Computer programmes were written in Fortran-77 and these programmes could be operated easily either through Unix system or window based DOS environment. The life table parameters and age distribution data of Creatonotus gangis could be calculated with great accuracy. Rearing of this insect on artificial diet based on dehusked red gram (flour) and dehusked green gram (flour) for three generations revealed that age specific survival (lx) remained constant for three to four week in different generations after an initial decrease due to constant egg mortality. The survivorship again started to decline due to mortality of older larvae and pupae, and after 40 days a sharp decline of lx was recorded due to high adult mortality. Though life expectancy of this insect increased for first few days but it was observed to fall with advancement of development. Survival fraction of the females initially remained constant for sometime but decreased steadily after 37.5, 38.5 and 36.5 days in first, second and third generations, respectively. Natality rate (mx) and net reproductiverate (R₀) of females in three generations were not similar during the whole length of reproductive period. The value of different life table parameters (T, Pf, R0, r, λ, DT & ARI) indicated more adequacy of the diet towards second generation. These findings revealed that suitability of the diet decreased to some extent if the rearing was continued further on this diet. Results on % contribution of different growth stages in stable condition revealed that the immature stages (egg & larval stages) contributed maximum in all the generations. Distribution of pupal stage was lower than egg and larval stages while adult distribution was very less. The finding indicated that the immature stages and not the adult stage decided the abundance of population.