This Winter’s Cold Weather May Help Control Some Insect Pests

Well, I for one have had enough of the 2013-2014 winter season.  Its March 13 and its snowing.  Again.  But this brutally cold winter season may have some beneficial side effects.  In a March 2, 2014 Worcester Sunday Telegram report, University of Massachusetts-Amherst Professor Joseph Elkinton notes that the extreme cold, down to 15 degrees below zero F in the Amherst area, will likely result in a large die-off of the Hemlock Wooly Adelgid, a non-native invasive insect pest that has devastated our hemlock forests and is a serious pest of hemlocks in our landscapes.  In the same article, Kenneth Gooch, Forest Health Program supervisor for the Department of Conservation and Recreation is optimistic, noting that the last time we had temperatures this cold, adelgid mortality reached 80%.  Keep in mind, however, that the reprieve is temporary.  The adelgids that do survive will eventually rebound, and may produce offspring genetically more resistant to cold temperatures.  And while I did not experience temperatures as cold as Professor Elkinton reported here in southern Worcester County or Windham County, we did have several nights of below zero temperatures, and some adelgid mortality results at temperatures as “warm” as 5 degrees F.

As much as I hate to admit it, we have had it easy here in New England.   The folks in the Midwest really got frosted and the south was exceptionally cold.  But again, more potential good news.  The Week magazine reports that the cold has killed 80% of the Emerald Ash Borer, another non-native invasive insect that has killed tens of millions of ash trees in the Midwest and has now been found in New Haven County, CT, western Massachusetts and North Andover, MA, and  New Hampshire.  The Week  also reports that large percentages of Gypsy Moths, Hemlock Wooly Adelgid, Corn Earworm, and the citrus destroying Cottony Cushion Scale have been killed off by the cold.

I don’t expect this to be the end of our problems with these invasive pests, but its comforting to know that some good can come from our having to endure the winter of 2013-2014.