Population parameters and growth ofRiptortus pedestris(Fabricius) (Hemiptera: Alydidae) under elevated CO2concentrations

We evaluated the direct effects of three different CO(2)concentrations (400, 600 and 1,000 ppm) on the population parameters and growth of the bean bug,Riptortus pedestris,while being fed on soybean. The raw life history data fromR. pedestriswas analyzed using an age-stage, two-sex life table to take the viable development rate among individuals into account. Based on the age-stage, two-sex life table analysis, the population projections ofR. pedestrisprovide the stage structure and variability of the population growth under different CO(2)treatments. Our results showed significantly shorter immature durations and higher pre-adult survival rate under elevated CO2(1,000 ppm) than those under ambient CO2(400 ppm). The population ofR. pedestrisreared under elevated CO(2)conditions showed higher intrinsic and finite rates of increase but a lower mean generation time thanR. pedestrisreared under ambient CO(2)conditions. Our results show the population parameters and growth ofR. pedestrisare influenced by increased CO(2)relative to ambient CO(2)treatment. Further studies on the long-term direct effects of different CO(2)levels onR. pedestrisare essential to understand their population dynamics and to establish appropriate management strategies.