Life table analysis under constant temperature for Opisina arenosella (Lepidoptera:Xyloryctidae), an invasive moth of palm plants

The coconut black-headed caterpillar Opisina arenosella Walker, which is spreading in Southeast Asia and southern China, is a significant pest of palm trees. All life stages of this species were reared at 20, 23, 26, 29, 32 and 35 °C to understand the effect of temperature on the biology of O. arenosella. Total developmental time egg to adult generally was longest (≈114 days) at 20 °C, declined significantly with increasing temperature, and shortest (≈47 days) at 32 °C. Estimated lower developmental threshold temperature was 11.5 °C, and estimated effective accumulated temperature was 996.93°days. A third-order polynomial model estimated an optimal temperature of 32 °C for development. The predicted number of generations per year was calculated as 4–5 under average climatic conditions experienced in Hainan, China. The oviposition period ranged from 2 to 4 days and was longest at 26 °C while fecundity ranged from 30 to 180 total eggs laid per female and was greatest at 32 °C. The highest reproductive values were found at 32 °C. At this temperature, net reproductive rate (R₀), generation time (T), intrinsic rate of increase (r_m), finite rate of increase (λ) and doubling time (DT) were 64, 45 days, 0.09, 1.1 and 7.6 days, respectively. Knowledge of the effect of temperature on the life history characteristics of Opisina arenosella can be used to predict population growth, develop pest management strategies and mass produce insects for production of biocontrol agents.