Forages & Grains
Volume 63 Number 10 Date 07/05/2018
POTATO LEAFHOPPER - Counts in alfalfa are increasing but remain below established economic thresholds. Surveys conducted in Adams, Dodge, Fond du Lac, Green Lake, Marathon, Marquette, Portage and Wood counties found a range of 0.1-1.0 adult and nymph per sweep and an average of 0.4 per sweep. Nymphs are appearing in more fields, indicating a potential for populations to increase this month.
PEA APHID - Sweep net counts in fields surveyed in the central and north-central counties ranged widely from 1-31 per sweep, with an average of 18 per sweep. These levels are considered high for late June.
ALFALFA WEEVIL - Pupation has begun as far north as Marathon County and feeding should subside next week. Larval populations in the central and northern areas have declined to low levels in the past two weeks, with 1-4 weevils per 100 sweeps being the typical count.
PLANT BUG - Combined averages of the alfalfa and tarnished plant bugs varied from 0.1-1.6 per sweep and averaged 0.5 per sweep. This represents a minor increase from last week's observations. Once again, the economic threshold for this pest (adults and nymphs) is 5.0 per sweep.
-- Krista Hamilton, DATCP Entomologist