The Effects of the Feeding of the Potato Leafhopper on Photosynthesis and Respiration in the Potato Plant1

Abstract

Gas exchange measurements were made upon sections of potato leaflet tissue which were damaged by feeding of the potato leafhopper, Empoasca fabae (Harris). Increases in respiration, accompanied by reductions in both apparent and true photosynthesis, were usually noted at the ends of the feeding periods. The photosynthetic depressions were quantitatively related to lengths of the feeding periods and the developmental stages of the insects. Although insect-induced changes in the rates of both respiration and apparent photosynthesis were most pronounced immediately after the feeding periods and declined thereafter, the reductions in true photosynthesis seemed to be permanently effected. Such reductions became distinctly pronounced as light intensities approached 2200 ft-c.