LONG-TERM EFFECTS OF ELEVATED CO2 AND TEMPERATURE ON POPULATIONS OF THE PEACH POTATO APHID MYZUS-PERSICAE AND ITS PARASITOID APHIDIUS-MATRICARIAE

Model terrestrial ecosystems were set-up in the Ecotron controlled env ironment facility. The effects of elevated CO2 (ambient + 200 mu mol/m ol) and temperature (ambient + 2.0 degrees C) on plant chemistry, the abundance of the peach potato aphid Myzus persicae, and on the perform ance of one of its parasitoids Aphidius matricariae, were studied. Tot al above-ground plant biomass at the end of the experiment was not aff ected by elevated atmospheric CO2, nor were foliar nitrogen and carbon concentrations. Elevated temperature decreased final plant biomass wh ile leaf nitrogen concentrations increased. Aphid abundance was enhanc ed by both the CO2 and temperature treatment. Parasitism rates remaine d unchanged in elevated CO2, but showed an increasing trend in conditi ons of elevated temperature. Our results suggest that M. persicae, an important pest of many crops, might increase its abundance under condi tions of climate change.