 Warmer temperatures and elevated CO2 levels were simulated for one field of soybeans, while the other was left as a control.These studies found that the soybeans with elevated CO2 levels grew much faster and had higher yields, but attracted Japanese beetles at a significantly higher rate than the control field.The beetles in the field with increased CO2 also laid more eggs on the soybean plants and had longer lifespans, indicating the possibility of a rapidly expanding population.