Insect Disease Guide
Safe tree removal company since 1984
INSECT DISEASE GUIDE by Mayer Tree
There are many insects and diseases located in Massachusetts and around our area that can have a negative effect on the health of your plants and shrubs. Mayer Tree Service has put together a guide to insects and diseases in our area to help homeowners.
This fungus is very common among flowering dogwoods, and several other trees. Initially it causes a dieback of new foliage, and works its way into the twig causing new twigs to die off. This can lead to a witches broom effect, a stunted appearance of the infected tree. Over time, the tree becomes weakened and vulnerable to secondary attackers such as dogwood borers.
This fungal disease is very disfiguring to the fruit and foliage of apple and crabapple trees. It can cause reduced vigor of the tree through reduced photosynthetic ability, as well as make the fruit unpalatable.
Asian Longhorn Beetle
Although not yet a pest on the North Shore, this beetle is present in Worcester County, and was also spotted in Jamaica Plain. This destructive pest favors maple, elm, horsechestnut, birch, and others. It is a large insect, with black and white segmented antennae, that leaves large exit holes in host trees.
Bronze Birch Borer
White birches are highly prone to infestation of the bronze birch borer, a small woodboring insect that will kill the host tree, usually first seen as dieback from the top downward.
While not a threat to tree health, these insects can threaten a tree’s structure. Carpenter ants will tunnel through dead wood, entering through old wounds and cracks.
This alternate host disease can distort the foliage, fruit, and twigs of apples and crabapples, but is mostly a cosmetic injury. For ornamental crabapples in areas of high visibility, it might warrant treatment.
This is a common fungal disease of blue spruce, as well as other evergreen tree species. Starting as dieback of lower branches, the disease slowly progresses up the tree, causing a decrease in health and aesthetics.
Fairly common in this area, diplodia infects and kills the new growth of hard pines, including red, Austrian, and Scotch. As the disease progresses, entire branches will begin to die, leading to tree mortality.
Dutch Elm Disease
First seen as “flagging”, this disease quickly spreads throughout the tree, and will usually kill it within 1-2 years. American elm is the most susceptible, and few old elms exist today because of this disease.
Emerald Ash Borer
Not yet known to be in Massachusetts, this pest has been spotted near the border in New York. The adult insect is of little consequence, but the larvae will feed in the vascular tissue of ash trees, disrupting the trees ability to move water and nutrients.
Fireblight is a potentially fatal disease of ornamental trees, especially apple, crabapple, and hawthorne. This bacterial disease leaves the appearance that the foliage was scorched.
Hemlock Woolly Adelgid
Often seen as white cottony masses on the undersides of the twigs of Canadian and Carolina hemlocks, this small aphid-like pest is a serious threat to our beautiful native hemlock trees.
Lacebugs are typically found on the undersides of leaves, feeding on the sap. These insects can produce a large population, especially on plants in sunny locations. Azaleas are their preferred host, where heavy populations can remove so much sap that they turn the leaves white.
Leafminers are larvae that feed inside of a leaf, causing noticeable damage. Peeling open an infested leaf will reveal small, wormlike insects. They are commonly found in birch, holly, and boxwood. Extensive feeding can lead to early leaf drop, and in evergreen plants could lead to plant death.