Volume 57 Number 18 Date 08/16/2012
CORN ROOTWORM - The statewide beetle survey is complete in all but the northeast area. Preliminary review of the field data indicates that counts are generally lower than last year in south-central, southwestern and central Wisconsin. Beetle counts in the northwest and north-central counties are somewhat higher. Results of the survey are summarized on in the CORN section.
CORN EARWORM - Migrants continue to appear in the south-central and central areas. Counts during the past week ranged from 0-250 per trap, with the highest number of moths being registered in the Westport trap. The latest activity indicates that routine scouting and control regimens in sweet corn should be maintained until harvest.
WESTERN BEAN CUTWORM - The seventh annual trapping survey has documented no significant change in counts in the state. The 2012 average moth count is 25 per trap, the exact same average as in 2011. A few moths persist in the east-central and northern areas, but the flight has essentially ended. Cumulative trap counts for the period of June 15-August 15 are shown in the map below.
SOYBEAN APHID - Densities remain extremely low in most fields. The highest count noted during surveys this week was only 64 aphids per 20 plants in a Jackson County field. Fourteen of 19 sites checked had no detectable aphid population. Many soybean fields are approaching R5.5-R6 (early to full seed), the growth stages at which no yield benefit is gained by insecticide treatment. Final aphid assessments should be made in the week ahead.
--Krista Hamilton, DATCP Entomologist