Jason Hamilton, biology, was invited to present a seminar entitled "Herbivory and Crop Losses in a High CO2 World" at a recent science colloquium at Wells College in Aurora.
Changes in the composition of leaves resulting from anthropogenic changes in the concentration of tropospheric carbon dioxide and ozone are predicted to alter losses to herbivory by insects. We measured herbivory in a soybean field exposed to elevated CO2 or O3 using free air gas concentration enrichment (FACE). Elevated CO2 increased herbivory by 125% early in the season, whereas, O3 appeared to have no effect. This increased herbivory was primarily a result of increased populations of the exotic species Popillia japonica (Japanese beetle). Chemical analyses and feeding trials suggest that increases in leaf sugars account for the increased herbivore populations and herbivory under elevated CO2.
Contributed by Nancy Pierce
