Population growth of the soybean aphid (Aphis glycines Matsumura) was studied under atmospheres with elevated atmospheric carbon dioxide corresponding to future conditions produced by anthropogenic climate change. Soybean aphids were placed on soybean plants grown under 550 ppm CO₂ or current ambient atmosphere (370 ppm) for a period of one week.

Results/Conclusions

Populations living on plants grown under elevated CO₂ significantly increased, ca. 16-fold, while populations living on plants grown in ambient atmospheric conditions increased only 8-fold. This difference in population growth rates may be due to differences in leaf temperature under the two atmospheric treatments. Plants grown under elevated CO₂ have reduced stomatal conductance and a denser canopy because of increased size; both of these factors lead to increased leaf temperature. As soybean aphids live within the boundary layer of soybean leaf surfaces, their temperatures may also be elevated under elevated CO₂, leading to faster growth and reproduction. Thus, global atmospheric climate change may exacerbate certain pest problems in agroecosystems.