Temperature-Dependent Development and Life Table Parameters of Octodonta nipae (Coleoptera: Chrysomelidae)

The effect of temperature on the development, survivorship, fecundity, and life table parameters of Octodonta nipae (Maulik) (Coleoptera: Chrysomelidae), was studied at seven constant temperatures of 17.5, 20, 22.5, 25, 27.5, 30, and 32.5 degrees C. Preliminary experiments showed that no development was observed at 15 and 35 degrees C. All individuals completed development and females laid eggs from 20 to 30 degrees C. There was a significant decrease in male and female longevity with increasing temperatures from 20 to 30 degrees C. The longest and shortest longevity were 203.5 and 73.7 d for males, and 178.7 and 57.6 d for females, respectively. Females produced on average 62.7, 88.9, 116.8, 70.0, and 47.3 eggs and the life expectancy for a newborn egg was 171.6, 148.7, 114.9, 89.2, and 94.8 d at 20, 22.5, 25, 27.5 and 30 degrees C, respectively. Life history data were analyzed by using an age-stage, two-sex life table. The intrinsic rate of increase (r) and the finite rate of increase (lambda) of O. nipae increased with increasing temperatures from 20 to 30 degrees C, while the mean generation time (T) decreased within this temperature range. The r was 0.0155, 0.0249, 0.0339, 0.0361, and 0.0383 d(-1) at 20, 22.5, 25, 27.5, and 30 degrees C, respectively. The net reproductive rate (110) was highest at 25 degrees C (35.0 offspring), and lowest at 20 degrees C (17.0 offspring). T was shortest at 30 degrees C (76.4 d). The results showed that temperature greatly affected the fecundity and life table parameters of O. nipae, and a suitable temperature for population development and fecundity was at 25 degrees C. The life table data can be used for the projection of population growth and evaluation of control programs.