Comparison of diapause and non-diapause induced Orius sauteri (Hemiptera: Anthocoridae) based on a two-sex life table in the laboratory

Abstract

The flower bug Orius sauteri (Poppius) is commonly used as an effective biocontrol agent for controlling small pest populations in greenhouses in China. The impact of two temperature and photoperiod regimes (26°C, L16:D8 h; 21°C, L8:D16 h) on the life table of O. sauteri was studied in the laboratory using an age-stage, two-sex life-table method. The results showed that the low-temperature short-photoperiod regime resulted in significant increases of the developmental times of the egg, the first to fifth nymphal stages, and the total preadult stage. Female adult longevity was significantly increased, whereas male adult longevity was significantly decreased, under this regime. Furthermore, the adult preoviposition period (APOP), the total preoviposition period (TPOP), and the sex ratio were all increased under this regime. Fecundity decreased, whereas the mean generation time (T) increased, as temperature and photoperiod decreased. The intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (Ro) all increased as the temperature decreased under diapause induction. Based on the estimated data, the higher r value (0.06d−1) occurred under the 26°C, L16:D8 h regime, compared with 0.03d−1, under the 21°C, L8:D16 h regime. Thus, the results showed that reproductive diapause slowed O. sauteri population growth, about 50% reduction based on r. There is significant interest in using O. sauteri as a biological control agent against non-diapausing small pests, such as thrips, in greenhouses under short photoperiods. However, based on the current results, managers should consider maintaining a high temperature and long photoperiod to prevent reproductive diapause induction in O. sauteri. Such conditions should not have a detrimental effect on the greenhouse crops.