Forages & Grains
Volume 64 Number 3 Date 05/16/2019
ALFALFA WEEVIL - Adults are appearing in very low numbers in alfalfa. The first small larvae should be detectable in advanced fields by May 20.
PEA APHID - Surveys this week found very low counts of 1-35 aphids per 100 sweeps. The average was 17 per 100 sweeps. Pea aphid development is favored by cool, dry weather, with populations increasing most rapidly at temperatures around 65°F. Heavy early-season aphid density can cause stunting of the first crop and damage to subsequent cuttings. Pea aphids are also suspected of transmitting certain alfalfa virus diseases.
TARNISHED PLANT BUG - Alfalfa sampled in Columbia, Dane, Grant, Green, Iowa, Lafayette and Rock counties had low counts of 1-7 per 100 sweeps. Plant bug abundance in the first-crop alfalfa is an indicator of potential high populations in apples, strawberries and other fruits and vegetables.
-- Krista Hamilton, DATCP Entomologist