Effect of temperature on the development and fecundity of Dianphania india (Saunders)
Abstract:
Abstract [Aim] To determine the effects of different temperatures on the growth, development and fecundity of Dianphania india (Saunders), and to determine the developmental threshold and effective accumulated temperatures. The findings of this study will provide a scientific basis for the measurement and comprehensive management of D. india. [Methods] Development threshold temperature, effective accumulated temperature, and life table parameters of D. india were analyzed in the laboratory under controlled temperatures of 21, 24, 27, 30, and 33 ºC. [Results] There was a significant effect of temperature on the different developmental stages of D. india. Egg duration (4.52 d), larval duration (25.32 d), pupae duration (13.98 d), female lifespan (56.44 d), male lifespan (52.79 d), and generation duration (46.15 d) peaked at 21 ºC. However, subsequent further increases in temperature resulted in an opposite trend, with all values gradually decreasing and reaching a minimum at 33 ºC. The developmental threshold temperature for egg, larva, pupa, adult, and whole generation were 13.54, 9.90, 14.28, and 15.00 ºC, respectively, and the effective accumulated temperatures were 38.00, 287.00, 77.72, and 277.60 degree·days, respectively. The intrinsic rate of increase (rm) (0.179 21) and the finite rate of increase (λ) (1.196 27) peaked at 33 ºC. However, female egg production began to decline at 33 ºC. The net reproductive R0 (84.212) rate was the highest at 30 ºC, while the gross reproductive rate GRR (94.486) was the highest at 27 ºC. The average generation time T at 21, 24, 27, 30, and 33 ºC was 43.027, 36.219, 28.097, 27.618 and 20.532 days, respectively. [Conclusion] Between 21 ºC and 33 ºC, the developmental duration of each state and the average generation time of D. india decreased with increasing temperature. The optimal temperature for reproduction was 27 ºC, whereas temperatures above 33 ºC were not conducive to D. india reproduction.