The first generation of Hemlock Wooly Adelgid will begin emerging in April and May. Hemlock Wooly Adelgid is an invasive insect pest that is devastating our native hemlock trees in New England. Adelgids are aphid-like insects that kill hemlock trees by feeding on their sap and injecting toxic saliva into the tree. Infested trees often die within 3 to 5 years. White, cottony masses at the base of the needles indicate that your tree has adelgids. Adelgids are readily controlled with horticultural oil sprays or systemics applied by trunk or soil injection. Spring is a good time for your Arborist to apply treatments to control the spread of this devastating pest.

If your crabapple trees were defoliated by mid-July last summer, then now is the time to take action so it does not occur again this year. The primary cause of this early defoliation is a fungal disease called Apple Scab. Apple Scab will not kill a tree, but reduces the aesthetic value of the tree. Three applications of a preventive fungicide beginning as the leaves are half expanded will keep your crabapple trees looking good all summer. Call in early April to get on the schedule for this important treatment.

Arborvitae often exhibit brown, dead needles at this time of year. This type of damage is often confused with winter damage but may be caused by the arborvitae leaf miner. This moth lays its eggs on the needles of arborvitae in June. The larvae of this pest eat the tissue inside the needle, leaving a hollow shell. The damage from this pest is often not evident until the following spring. Insecticides applied in June when the adults are laying eggs can control this pest.

For information on other common seasonal pests to look for in your yard visit the UMass Extension Landscape Message website.