Impact of Temperature on Age-Stage, Two-Sex Life Table Analysis of a Chinese Population of Bean Bug, Riptortus pedestris (Hemiptera: Alydidae)

Riptortus pedestris Fabricius (Hemiptera: Alydidae) is an economically important pest of soybean that causes serious damage in the Huang-Huai-Hai region of China, which is the main soybean-producing area. However, the basic biological and ecological attributes of the Chinese populations of R. pedestris are still unknown. Temperature is a critical factor influencing insect population dynamics; therefore, understanding the effects of temperature on individual development and population growth of R. pedestris is helpful to forecast the pest's phenology as part of its control. In this study, we determined age-stage, two-sex life table parameters of R. pedestris at five constant temperatures (19, 22, 25, 28, and 31 degrees C) under laboratory conditions. The results demonstrated that the developmental period, preadult time, adult longevity, adult preoviposition period (APOP), and total preoviposition period (TPOP) were all significantly shortened when the temperature increased from 19 to 31 degrees C. The developmental time from egg to adult was 55.00 d at 19 degrees C but decreased to 24.43 d at 31 degrees C. The developmental threshold temperatures of the egg, nymph, female adult, male adult, and total generation (from egg to adult death) were 13.31, 10.91, 16.21, 17.13, and 13.44 degrees C, respectively, and the corresponding stage-specific day degree totals were 95.91, 260.51, 114.22, 147.35, and 582.04. The net reproductive rate (R-0 = 2.36 offspring), fecundity (58.00 +/- 28.59 eggs), and population trend index (I) (7.89) were found to be optimal at 25 degrees C. These results could be useful for predicting the population dynamics of R. pedestris and improving the management of this pest in field crops.