Field averages greater than 0.75 beetles/plant in continuous corn can be expected to have significant egg-laying that would justify larval management the follow year.
To scout, walk a "W" shape pattern to reach 10 random sampling areas of the corn field. Count the number of corn rootworm beetles on five plants in each random area of the field. Pick plants that are not right next to each other. Beetles can be found on the tassel, top and bottom of leaves and in the silk. Continue scouting in nine other random areas of the field so that you examine a total of 50 plants. Repeat this scouting procedure at 7-10 day intervals one or two more times.
Bryan Jensen, University of Wisconsin Integrated Pest Management (IPM) program.
Also check "IPM Decision Aid: Managing corn rootworm BT resistance" here --- [ Ссылка ]
Further information can be found here --- [ Ссылка ]
The UW IPM website is here --- [ Ссылка ]
