UMass Extension Landscape Message November 2, 2012

"Winter Moth, Fall Cankerworm, and Bruce Spanworm moths will be active very soon. These adult moths, especially the males of each species, are noticeable every November, usually beginning around the second or third week in November in MA. However, the record-setting warm temperatures of the late winter of 2012 and above-normal early spring temperatures accelerated insect activity for this year. We may very well begin to see the drab-colored moths of these species at our porch lights any evening now. They tend to especially become active on a relatively warm evening following a rain. The adult females do not fly and are generally only seen if visually sought out on tree trunks. Bruce spanworm males are common throughout MA (and all of New England) and are the primary 'late-season moth' that is witnessed at night at this time of year in central and western MA. Bruce spanworm is rarely a pest. The coastal areas of MA, as well as, most of Rhode Island now have winter moth in fairly high numbers. UMass researchers have been once again deploying hundreds of pheromone traps to identify areas of the state with especially high population numbers of this pest. Last year's counts for winter moth in MA were at historically high levels and much defoliation from the caterpillars was expected this spring but the record high temperatures of March 2012 in MA resulted in much mortality for the over-wintering eggs. That, along with the extremely early egg hatch and lack of available foliage to feed upon resulted in much lower than expected defoliation this past spring. However, winter moth has the ability to rebound fairly quickly and numbers of egg-producing female winter moths may be high enough to create problems for our trees next spring. Reports will follow as to the findings of the trapping efforts.

Reported by Robert Childs, Extension Entomologist, Plant, Soil and Insect Sciences Department, UMass, Amherst"

Excerpt from above report: "Bruce spanworm males are common throughout MA (and all of New England) and are the primary 'late-season moth' that is witnessed at night at this time of year in central and western MA. Bruce spanworm is rarely a pest. The coastal areas of MA, as well as, most of Rhode Island now have winter moth in fairly high numbers."

Claire