Alfalfa Weevil Scouting

The Wayne County Extension IPM scouting program has been monitoring ten alfalfa and alfalfa/grass mix fields for alfalfa weevil larvae since the beginning of May.  Although weevil larvae numbers have increased somewhat over the past couple of weeks, numbers are well below threshold treatment levels and this appears to be consistent across the state this year.  Our scouting and sampling have resulted in averages ranging from 0.33 to 0.50 larvae per stem when sampling 5 to 6 random areas for every 25 acres.  Alfalfa height on our last sample date of May 14 averaged from 15 to 25 inches across ten different fields.  At this point, even if threshold levels were detected, the recommendation would be to take harvest cutting rather than apply a rescue insecticide treatment. 

For more information about how to scout for alfalfa weevil larvae, how to identify the larvae and threshold treatment levels watch this short video clip located on the OSU Extension Forages website: https://forages.osu.edu/video.

About the C.O.R.N. Newsletter

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.