Annual bluegrass weevil season is over for most New England golf courses. The second/summer generation has completed development and most of the emerged adults are expected to prepare physiologically to overwinter and to migrate to overwintering sites soon. However, it is possible that a small portion of the population will still lay eggs at this time and some larvae might be still present. The third generation larvae should stop feeding by the end of September. Cooler temperatures favor grass growth, thus, severe damage is not expected. Monitoring the most sensitive areas for larvae presence and abundance is still recommended. The best approaches to monitor ABW at this time of the year are taking soil cores and using salt flushes for larval extraction.
White grubs are actively feeding and growing, therefore damage may become visible. Preventive applications should have been conducted earlier in the season. If there are strong indications of grub activity and damage, curative application may be warranted. Use of trichlorfon is the most common curative approach (please note that trichlorfon is not available for use on school grounds in Massachusetts and several other states).
Submitted by: Dr. Olga Kostromytska
