Age-Stage, Two-Sex Life Table of Geocoris xishaensis at Different Constant Temperatures

Temperature is a critical determinant of development and reproduction in predatory bugs of the genus Geocoris. Here, we examined thermal effects on life-history traits of Geocoris xishaensis Zhou, Cai & Gao (Hemiptera: Geocoridae), a species recently described from Hainan, China. Individuals were reared on embryo-inactivated eggs of Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) at six constant temperatures (16, 20, 24, 28, 32, and 36 °C), and developmental duration, survival, and fecundity were recorded. Age-stage, two-sex life tables were constructed, and 60-day population dynamics were projected. Geocoris xishaensis failed to complete a whole generation at 16 °C and 20 °C. Between 24 °C and 36 °C, developmental duration of each stage decreased with increasing temperature. Female fecundity was highest at 32 °C (241.12 eggs) and 28 °C (184.00 eggs). For the total generation period (including the adult preoviposition period), the lower developmental threshold was estimated to be 17.35 °C, with a corresponding thermal constant of 376.42 degree-days. The estimated number of annual generations of G. xishaensis in Hainan ranges from 7.3 to 8.45. The intrinsic rate of increase (r) and finite rate of increase (λ) both peaked at 32 °C, reaching 0.0961 day−1 and 1.1008 day−1, respectively. Sixty-day population projections revealed increasing trends at 28–36 °C. These results indicate that, of the temperatures tested, 32 °C gave the best overall performance, followed by 28 °C; both can therefore be recommended as suitable temperatures for mass rearing.