Current Conditions
Fluctuating weather conditions continued over the past couple of weeks, with a cold front replacing warm temperatures with raw, windy, damp weather. Seasonal temperatures were mixed in with brief periods of heavy rain in some places and drastic overnight lows. Crabapples, cherries, horsechestnuts, rhododendrons, azaleas, redbud, Amelanchier, lilacs and viburnums are coming into full bloom. Full leaf out is almost complete, with some oaks still slowly unfolding foliage. Soil temperatures are at an average of 56 degrees, with some regions experiencing flooding while others are dry, monitor plants and adjust watering regime accordingly. Much of the northeast has received only 0.30 inches of rain, but the soil seems to have retained moisture. Weeds are breaking through in lawns and in beds. Wintermoth caterpillar, hemlock woolly adelgid (the population in the north east appears smaller this year, most likely attributed to the extended, cold winter) and black legged ticks continue to be active as more pests appear on the scene.
Prevailing Pests
Discussed below are some of the insects whose activity has recently been noted. This is not an all inclusive list, please coordinate with your arborist regarding your landscape concerns and possible treatments.
Balsam twig aphid are usually the first aphids to appear, typically found on Frasier and balsam firs. They reproduce in large numbers which immediately begin feeding on newly emerged foliage.
Feeding from balsam twig aphids causes needles to become twisted and distorted. Aphids also produce copious amounts of sticky honeydew which coupled with feeding stunts and twists new growth. This damage stresses plants and diminishes aesthetic value making Christmas trees unsaleable.
The honeylocust plantbug appears at budbreak and becomes active when temperatures are steadily warming. They immediately begin to feed on foliage.
Damage from honeylocust plantbugs appears as yellow patches and leaf stippling and when population numbers are high, foliage will emerge very slowly and be severely damaged.
Examine susceptible evergreen species such as rhododendrons, azaleas and andromeda for lacebug damage from previous seasons which will appear as yellow stippling on the underside of leaves and mold-colonized honeydew on stems. If lacebugs were present the preceding season, they may become an issue again.
Lacebug damage on leaves, make sure that your arborist knows that there is an issue to prepare for next season.
Snowball aphids become active directly following budbreak and are commonly found on various viburnum species.
Damage from snowball aphids presents as curling, twisted and distorted foliage which is mainly an aesthetic issue. By the time damage is observed it is too late to control current populations, but consult your arborist for possible treatments for next year.
Spruce spidermite hatched out earlier in the season but is still active on spruces, firs, arborvitae and hemlocks. Follow up applications will provide additional population control.
Damage from spruce spidermites appears as yellowed stippled needles occurring in large patches on trees.
Plants experiencing the above stated pest problems may have been identified and planned for earlier in the season. Continue with management plan as provided by your arborist, weather conditions may affect timing of applications but adjustments will be made to provide the most effective control. Contact your arborist should you have further concerns or if you suspect a new problem has cropped up.
