As reported by Dr. Carole Cheah of the Connecticut Agricultural Experiment Station, the hemlock woolly adelgid population in Connecticut suffered its highest rate of mortality this past winter in 16 years of record-keeping. Along the shore, average mortality was nearly 95%, while it the northwest corner of the state, mortality approached 100%.
Dr. Cheah presents these observations, along with comparisons with the results of previous years, in a Station fact sheet entitled, “HWA Winter Mortality in Connecticut & Implications for Management and Control“. This fact sheet can be found through the publications page on the Station web site (www.ct.gov/caes), under fact sheets and then under pdf’s.
Dr. Cheah describes two factors as contributing to this record-breaking die-off. Primarily, it was the extreme cold that arrived as part of a mid-February polar vortex and that affected the whole state. Also, because the winter had been mild previous to this cold snap, there was little snow accumulation within the tree canopy, and so the insects had little protection from the cold. She also includes the observation that, again due to the previous mild weather, many of the insects that were killed were at a later stage in their development.
Throughout the fact sheet, Dr. Cheah takes note of the various management implications that arise from these observations.
In a related note, Dr. Kirby Stafford has updated the gypsy moth fact sheet to include information from this current year. This fact sheet is available on the CAES web site as well.
Dr. Cheah will be attending the CTPA Summer Meeting on Thursday, July 21, along with several other Station Scientists – so please, register to attend the meeting and come with your questions, your own observations regarding trees, insects and diseases, and also any samples you might wish to discuss with these researchers.