Copyright © 1988 Published by Elsevier B.V.
Received 29 April 1987;
Two soybean [Glycine max (L.) Merr.] cultivars, Forrest and Essex, were exposed to incremental levels of O3 in open-top field chambers during the 1986 growing season. Treatments consisted of chambers receiving carbon-filtered air or non-filtered air to which either 0.00, 0.03 or 0.06 ppm (μl/l)O3 was added continuously for 7 hr/day. After 3 weeks of exposure, the feeding preference of Mexican bean beetle (MBB) adults (Epilachna varivestis Mulsant) was determined by placing plants in a carbon-filtered chamber enclosed by an aluminum screen. Defoliation was visually determined after the MBB had fed for 6–8 days. Leaves from the remainder of the plants were brought to the laboratory and fed to MBB larvae. The larvae were reared in plastic boxes until pupation, and developmental time, pupal weight and mortality were determined. Visible O3 injury increased significantly with increasing O3 concentration and Forrest was significantly more sensitive than Essex. No cultivar differences were found in MBB adult feeding preference, but defoliation increased significantly with increasing O3 concentration. Results, although not as definitive as in the feeding preference study, indicated that MBB larvae tended to weigh more and develop faster on ozonated foliage. Implications of this pollutant × pest interaction are discussed relative to its potential impact on crop production.