The western corn rootworm, Diabrotica virgifera virgifera LeConte, is an established insect pest of maize (Zea mays L.) in North America. The rotation of maize with another crop, principally soybeans, Glycine max (L.), was the primary management strategy utilized by North American producers and remained highly effective until the mid-1990s. In 1995, widespread and severe root injury occurred in...

Resistance management is essential for maintaining the efficacy and long-term durability of transgenic corn engineered to control western corn rootworm (Diabrotica virgifera virgifera Le Conte). Theoretically, a refuge can be provided by growing susceptible (refuge) plants in either a separate section of the field adjacent to resistant (transgenic) plants, or as a seed mixture. We examined the ...

The widespread planting of crops genetically engineered to produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt) places intense selective pressure on pest populations to evolve resistance. Western corn rootworm is a key pest of maize, and in continuous maize fields it is often managed through planting of Bt maize. During 2009 and 2010, fields were identified in Iowa...

Corn rootworm (CRW) beetles exhibit a univoltine life cycle. Feral adults deposit their eggs into the soil of cornfields during July and August where they undergo diapause and overwinter. The following spring eggs hatch beginning in late May and continuing on into the middle part of June. Larvae of the new generation feed on developing corn roots. After reaching the third instar larvae pupate i...

NADH:nitrate reductase was extracted from corn leaves (Zea mays L. W64A x W182E) and purified on blue Sepharose. After the nitrate reductase was further purified by polyacrylamide gel electrophoresis, it was used to immunize mice and a rabbit. Western blots of crude leaf extracts were used to demonstrate monospecificity of the mouse ascitic fluids and the rabbit antiserum. The electrophoretic p...

We examine the usefulness of various imaging techniques, including optical ow, for measuring plant growth for corn seedlings and Caster Oil Bean leaves. A near-infrared camera, which allows one to measure optical ow in the light and in the dark, is used. For corn seedlings we have already used optical ow to obtain 3D image velocity as a measure of growth performance. We propose two new growth m...

Densities of the root-knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood,were compared following summer crops of tropical corn (Zea mays L.) and sorghum (Sorghum bicolorL.) at several locations in north Florida. Densities of M. incognita remained low soil) following the sorghum cultivars DeKalb FS25E and DeKalh BR64 and the sorghum­ sudangrass (S. sudanense [Piper] Stapf) hybrid D...