ARS | Publication request: PLANT-TO-PLANT AND ROW-TO-ROW MOVEMENT OF WESTERN CORN ROOTWORM LARVAE

Submitted to: Entomological Society of America Annual Meeting North Central Branch
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 1999
Publication Date: N/A

Technical Abstract: The western corn rootworm is a major insect pest in continuous corn production, but no viable alternatives to insecticides are available for its control. Seed companies have announced commercialization goals for transgenic seed with resistance to corn rootworm larval feeding as early as 2001, yet little is known about certain aspects of corn rootworm biology that may be required as part of the registration process by the Environmental Protection Agency. The goal of the present study was to determine if and how much western corn rootworm larvae move from plant to plant and row to row after larval establishment. Plots were divided into two row spacings (91.4 cm and 45.4 cm) and two plant spacings (16.5 cm and 24.1 cm). For each plot, a central plant was infested with 1,500 viable western corn rootworm eggs. After egg hatch, soil cores were taken from the infested plant, the closest six plants within the row, and the two closest plants in each of the closest two rows. Four replications were sampled for each row space/plant space combination at three dates throughout the season. In the 1998 growing season, significant larval movement was observed between plants within a row, but little movement was observed between rows. The results may impact determinations of the most appropriate type of "refuge" for transgenic crops with resistance to corn rootworms.