Agriculture & Natural Resources

IPM- Alfalfa Sampling Guidelines

University of Delaware – March 2016

Joanne Whalen – Extension IPM Specialist and Bill Cissel – Extension IPM Agent

Pest
Sampling Method
Growth Stage: Mid- March to First Cutting
Alfalfa weevil Minimum of 30 stems per field collected in a W-pattern, place stems top first in bucket, measure stem height and count the number of larvae per stem
Pea aphid  Collect a minimum of 30 stems per field and  count the number of aphids and beneficial insects present per stem ( e.g. lady beetles and syrphid fly larvae )
Growth Stage: After First Cutting (mid-May) to September
Alfalfa weevil – only for 2 weeks after first cutting Minimum of 30 stems/crowns per field in a W-pattern, place stems top first in bucket and count the number of larvae per stem/crown
Potato leafhopper Ten sweeps in ten locations – plants should be dry
Blister Beetle 10 sweeps in ten locations<
Garden webworm and other defoliators Estimate defoliation in 10 location