Temperature-dependent biological and demographic parameters of coleomegilla maculata (Coleoptera: Coccinellidae)

Abstract

Knowledge of the most suitable environmental conditions for an organism growth and development is a prerequisite for developing mass rearing technology. The temperature requirements for development and the optimal range of temperatures for growth and reproduction of Coleomegilla maculata De Geer were studied. The development time of individual C. maculata larvae was determined at 18, 21, 24, 27, 30, 33, and 36 °C. Development times were converted to development rates and fitted to a nonlinear temperature-dependent model and to the linear day-degree model. Life and fertility table analysis was used to determine the optimal temperature for population growth within a range of favorable temperatures including 24, 25, 26, 27, and 28 °C. Nonlinear estimates of thermal maximum (TM) for the postembryonic development of C. maculata was 35.09±10.35 °C. Estimation of TM based on pupal development was much lower at 27.23±1.52 °C. Linear and nonlinear estimates of low temperature development threshold were 13.136and 4.77±3.03 °C for the whole postembryonic development and 10.95 and 9.18±1.36 °C for the pupal stage alone, respectively. The most favorable temperature for population growth was 25 °C, where C. maculata showed significantly higher intrinsic rate of increase (rm=0.066) and significantly lower doubling time (10.57 d) than the other favorable temperatures tested. A negative value of rm was obtained at 28 °C, indicating population decline occurring at this temperature making it unfavorable for C. maculata.