Influence of western corn rootworm (Coleoptera : Chrysomelidae) larval injury on photosynthetic rate and vegetative growth of different types of maize

Two field experiments were conducted in 1995-1996 to determine if there are common photosynthetic and vegetative growth responses among genotypes of m aize, Zea mays L., to larval western corn rootworm, Diabrotica virgifera vi rgifera LeConte injury. Specific variables measured from rootworm infested and noninfested giants were midday leaf photosynthetic rate, plant growth s tage, and plant height during 9-18 leaf growth stages. Three yellow-dent hy brids. Eve white food-grade dent hybrids, and a popcorn hybrid were include d in the study. Results suggest that there may he a common negative photosy nthetic response within maize to larval injury during vegetative growth sta ges. Transient reductions in photosynthetic rate occurred in rootworm infes ted maize at both low to moderate levels of root injury, which after a lag period, led to significant reductions in plant height. This trend was consi stent across hybrids in both experiments during each year. Plant growth sta ge was not significantly affected by rootworm injury during vegetative peri ods.