To provide the highest level of professional tree and shrub care to Philadelphia’s Main Line Communities, we pride ourselves on constant research.
Ours is a very specific and narrow field that requires learning through experience. Each property is unique and every year is different. To keep up with the latest thinking, we initiate contact with the leading arborists, entomologists and pathologists of our industry to discover and implement the best practices available for Plant Health Care.
See the most recent information on the pests and diseases that can affect your property through our gathered resources here.
Order By: Plants A-Z Diseases A-Z Insects A-Z
The disease is most severe in nursery stock and seedlings where plants are grown closely together.
The bagworm is a perennial insect pest of arborvitae, juniper, pine, spruce, and many other evergreen species.
The Spruce Spider Mite is considered one of the most destructive spider mites in the United States.
The Fletcher Scale, sometimes referred to as the arborvitae soft scale, is a common pest of arborvitae and yew.
The Japanese cedar longhorned beetle is an exotic insect that bores into trees of the cypress family.
Pestalotiopsis is a type of needle blight fungal disease that is primarily found on arborvitae (Thuja). It is usually considered...
Bark beetles, family Scolytidae, are common pests of conifers (such as pines) and some attack broadleaf trees. Over 600 species...
Many deciduous hardwoods are susceptible to a leaf disease called anthracnose that is caused by various species of the fungus...
Ash leaf rust is one of the most spectacular rust diseases of trees in the Northeast.
Ash yellows is a recently discovered disease that causes slow growth and decline of ash (Fraxinus) species.
Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an exotic beetle that was discovered in southeastern Michigan near Detroit in...
Whiteflies are white insects with pale yellow bodies that are approximately 2 mm long.
The elegance and beauty of azaleas and rhododendrons in bloom at the nursery have caused many an unsuspecting gardener to...
Informational table showing disease name, symptoms, pathogen/cause, and management of Azalea and Rhododendron diseases.
Cankers girdle and kill twigs and branches.
Leaf and flower galls are commonly found on many flowering woody hosts, most often on azalea and camellia.
Fungus-like organisms belonging to the genus Phytophthora are soil- or plant-borne and all are plant pathogens.
While some powdery mildews attack a very few specific plants, others have a broad host range and infect many different...
The adult female azalea bark scale is dark red with short legs and antennae and long, sucking mouth-parts.
Twenty-eight lace bug species have been recorded in Pennsylvania, but only a few are key pests of ornamental evergreen plants...
This species was intercepted 131 times at U. S. ports-of-entry between 1995 and 2012, with specimens originating from Brazil, China,...
The female adult is about 0.38 mm long and resembles a small spider.
The European fruit lecanium is a key soft scale insect pest of shade trees and other woody ornamental plants in...
This microscopic mite is an eriophyid mite that is most active during the warm season. Damage will appear as reddish...
Beech bark disease causes significant mortality and defect in American beech, Fagus grandifolia (Ehrh.).
Bleeding Canker is a potentially lethal disease to mature European Beech trees (Fagus sylvatica).
The beech scale (Cryptococcus fagisuga Lindinger) was first found in the U.S. in Massachusetts and Maine in the 1930s.
These sap-sucking insects cover themselves with waxy filaments to deter predators.
Many species of aphids or plant lice occur on ornamental trees and shrubs in Pennsylvania.
The twolined chestnut borer, Agrilus bilineatus (Weber), belongs to the beetle family Buprestidae.
Granulate ambrosia beetle was introduced to South Carolina from Asia in the early 1970’s.
Lycorma delicatula, commonly known as the Spotted Lanternfly (SLF), is a new invasive insect that has spread throughout southeastern Pennsylvania...
Many species of aphids or plant lice occur on ornamental trees and shrubs in Pennsylvania.
A moderately common pest problem observed on hawthorn trees in May and June is the hawthorn leafminer, Profenusa canadensis. The...
Japanese beetle, Popillia japonica, is one of the best-known pests to be encountered by Pennsylvania fruit growers, nursery operators, and...
The fall webworm is a widely distrubuted native pest of shade trees and shurbs and appears from late...
Spider mites are not insects, and are more closely related to spiders.
Both American and English boxwood are susceptible to this disease caused by the fungus, Pseudonectria rouselliana.
New to the U.S., Boxwood Blight was first described in the United Kingdom in the mid-1990s. Infecting all aboveground portions...
An overview of the types of diseases that affect the Boxwood. Phytophthora typically occurs in compacted soils with poor drainage.
The boxwood leafminer is a serious pest of Pennsylvania plantings of boxwood.
Monarthropalpus flavus
The boxwood psyllid is a common pest of boxwood, but not considered as destructive as other boxwood pests.
The boxwood spider mite, Eurytetranychus buxi, becomes active in late April, early May in Oregon. The mites overwinter in the egg...
Indian wax scale insects are tiny, brownish-purple females with microscopic legs and a thick covering of sticky, white wax. There...
The juniper scale, native to Europe, is now distributed throughout the United States. This armored scale insect occasionally becomes a...
Black knot is a fungal disease that affects several species of Prunus. Outbreaks are common in both landscapes and natural...
Cherry leaf spot, caused by the fungus Blumeriella jaapii, attacks the leaves, leaf stems, fruit, and fruit stems of tart,...
Cytospora canker is one of the most destructive diseases of peaches, nectarines, apricots, sweet cherries, and plums in Pennsylvania.
Gummosis is the oozing of sap from wounds or cankers on fruit trees.
On ornamental cherries, the first symptoms often seen are browing and collapse of the blossoms followed closely by death of...
The Eastern tent caterpillar has been observed in the United States since 1646.
Cottony maple leaf scale females are 3 to 4 mm long and 2 to 4 mm wide. They are slightly...
What was formerly considered to be a single species of scale known as the white peach scale, has been determined...
The peachtree borer, a native insect, is a major pest of stone fruits in the United States and Canada.
Shothole can present as necrotic leaf spots with circular to irregular margins. Bacterial spots are brown surrounded by a reddish...
Fire blight is a disease caused by the bacterium Erwinia amylovora. Twigs, branches, and leaders on trees and shrubs wilt...
Lace bugs are common pests of a variety of ornamental trees and shrubs.
Venturia inaequalis
Apple scab is Pennsylvania's most important apple disease, attacking wild and cultivated apple and crabapple. Dull, olive-green areas visible on...
Cedar apple rust and closely related diseases, cedar-quince, cedar-hawthorn, and Japanese apple rusts are caused by fungi belonging to the...
A couple years ago I began warning about a new pest that was spreading throughout crape myrtle country. Now, the...
Crape myrtles are among the most commonly planted trees in the Southeast. The two main pests are crape myrtle bark...
Cryptomeria scale is an armored scale found on the underside of needles.
Larvae feed in the inner bark of live, healthy dogwood trees. The damaged area of the trunk or branch swells and eventually...
Adult sawflies are wasplike. After the second molt, larvae become covered in a white powdery substance.
A look at diseases, symptoms, causes and management of diseases that can affect the Dogwood tree.
The early symptoms of discula anthracnose begin in mid to late May as leaf spots with tan or purple borders.
Like most other fungal diseases, Swiss needle cast favors rainy, moist, and cool weather. Fruiting bodies develop through the stomata...
Diplodia (formerly Sphaeropsis) tip blight is caused by the fungus Diplodia pinea. It is the most common and severe disease...
Cytospora canker of conifers is caused by Valsa kunzei. From a distance, the most obvious symptom is dead or dying...
Douglas-fir is the only known host of Rhabdocline. Rhabdocline needle cast infection occurs around bud break, when buds are opening...
Small, black, slightly raised, rough spots form on leaves. Leaves yellow and fall prematurely.
Three species of bark beetles are associated with elms in the United States.
The elm leaf beetle is an introduced pest that feeds only on speecies of elm.
Mature females are up to 10 mm long oval and grayish-brown with a white waxy fringe ovisac.
Dutch elm disease (DED) is one of the most destructive shade tree diseases in North America. The disease affects American...
Elm yellows symptoms begin in mid to late summer with the chlorosis and drooping of petioles of turgid leaves and...
Botryodiplodia canker is caused by fungal species in the genus Botryodiplodia. The signs are small, black, pimple-like fruiting bodies (pycnidia)...
The English ivy is a hardy evergreen vine that is grown widely as a ground cover under trees and in...
This species was intercepted 131 times at U. S. ports-of-entry between 1995 and 2012, with specimens originating from Brazil, China,...
The euonymus scale is a key pest of deciduous and evergreen euonymus.
Euonymus Alatus Scale symptoms include yellowing of foliage and dieback of branched in heavy infestations. Heavily infested plants have been...
The Japanese maple scale is a recently detected pest of a wide range of woody host plants in Pennsylvania.
The two-spotted spider mite has been reported infesting over 200 species of plants. This mite can be found on deciduous...
The elongate hemlock scale sometime known as the fiorinia scale, is a serious scaled insect pest of hemlock.
Bacterial blight of lilac, also known as shoot or blossom blight, is caused by the bacterium Pseudomonas syringae pv. syringae....
Eastern Filbert Blight is caused by the fungus Anisogramma anomala and is indigenous to the Northeast United States.
A moderately common pest problem observed on hawthorn trees in May and June is the hawthorn leafminer, Profenusa canadensis. The...
Adult eriophid mites are minute, yellowish-orange, spindle-shaped mites with four legs.
The most obvious sign of a hemlock woolly adelgid infestation is the copious masses of white filaments of wax produced...
The fungi Coniothyrium ilicinum and Phacidium species are two of several that regularly cause leaf spots on holly (Ilex) in...
Cottony camellia scale is a soft scale that feeds on camellia, holly, yew, euonymus, sweetbox, and maple.
American holly foliage is damaged by the feeding activity of larvae that destroy leaf tissue between the upper and lower...
The honeylocust plant bug is a key pest of honeylocust.
Adult mites that have overwintered are less then 1 mm long and orange.
The mimosa webworm feeds primarily on the leaves on mimosa and honeylocust trees.
Small irregular, reddish-brown spots and large blotches with yellow halos form in late June or early July. Most infected leaves...
An overview of Hydrangea diseases including Botrytis Blight, Cercospora Leaf Spot, Virescence and others.
Lace bugs are exclusively plant feeders, and while more species occur on herbaceous plants, the most common species occur on...
Junipers (Juniperus sp.), also known as red cedars are susceptible to a disease that results in the death of twig...
An overview of Juniper diseases including cedar-apple rust, cercospora blight and more.
Caterpillars of this species are very small and one of their first actions is to cut off a needle tip...
Cercospora leaf spot generally is not a serious disease of leucothoe. However, in years with a cool, rainy spring, Cercospora...
Plants are stunted; leaves yellow and wilt as branches die. Many dark-brown to black lesions form on roots, enlarge, and...
This pest is most commonly recognized when the nymphs make the bubbly spittle masses on small branches of conifers.
Seiridium canker is perhaps the most significant and damaging disease on Leyland cypress. This fungus is commonly associated with both...
Adult lilac (ash) borers are moths that vary in color from brown to yellow to orange. They have clear wings...
Foliar symptoms caused by Phytophthora canker reflect the disruption of water transport within the infected plant. Early symptoms include leaves...
Early indications that a tree has Verticillium wilt include heavy seed production, leaves that are smaller than normal, and the...
The magnolia scale is one of the largest scale insects in the United States. It feeds only on magnolia. This...
A photo of magnolia scale infestation.
Leaf spot is a common descriptive term applied to a number of diseases affecting the foliage of ornamentals and shade...
The cottony maple scale is a highly modified insect pest that commonly attacks silver and red maples in Ohio.
An overview of certain diseases of trees that weaken their structure and create a hazardous situations.
The appearance of lichens are often related to damage from environmental stress or poor management. Exposed limbs on damaged plants...
The yellow-bellied sapsucker is the only member of the woodpecker family to cause the type of injury from boring numerous...
Weather conditions during the past few winters have been conducive for injury to woody ornamentals.
Drought can impact many types of woody plants in landscapes, natural woodlots, and forests.
Excess water can be a serious problem for many woody ornamentals.
Bacteria and fungi help organic matter decompose, so it is only natural that such mulches will sometimes have fungi and...
Walnuts and hickories produce the chemical juglone (5 hydroxy-1,4- napthoquinone), which is exuded from all parts of the plant.
The rhododendron borer is one of the smallest clearwing borers found in Pennsylvania.
Leaf Spot on Mountain Laurel will have large, tan to brown spots on leaves with a dark line on their...
Bark beetles, family Scolytidae, are common pests of conifers (such as pines) and some attack broadleaf trees. Over 600 species...
The gypsy moth was accidentally introduced into Massachusetts in 1869.
About 160 species of lace bugs have been described in North America.
Obscure scale is a key pest of oak in Pennsylvania.
Leaf scorch, sometimes called marginal leaf burn, describes the death of tissue along the edge of the leaf. This symptom...
Tubakia leaf spot is different than anthracnose, so consultants and homeowners have questioned whether they should be concerned. Tubakia lesions...
Brown to tan spots on the leaves are small at first but enlarge and may cover the entire leaf.
Alfalfa mosaic virus has a broad host range that includes over 600 plant species in 70 families.
Pear scab resembles apple scab in nearly all respects and is caused by the closely related fungus Venturia pirina. Although...
Symptoms on pear begin as yellowish-orange leaf spots early in the season. Young fruit and twigs can also be infected.
These cylindrical, brown to black beetles are usually very small, 1/6 to 1/8-inch, but they can cause considerable damage. Fortunately,...
Austrian, Scots, ponderosa, mugho, red and other 2 and 3-needled pines are susceptible to the killing of shoot tips and...
Procera root rot also known as white pine root decline is caused by a fungus. It infects the inner bark...
White pine sheath mite, Setoptus strobacus Keifer, can be found in the needle sheath and on the needles of eastern...
The white pine weevil is considered the most destructive insect pest of eastern white pine in North America.
A tree heavily infested with pine bark adelgid may have the look of snow on its branches and trunk.
The pine needle scale is considered a key pest of pines in landscapes, nurseries, and Christmas tree plantations in Pennsylvania.
This minor pest of eastern white pine is best recognized by the symptoms it produces rather than by the appearance...
The most common sawfly species that attacks pines in Pennsylvania is the European pine sawfly.
Austrian, Scots, ponderosa, mugo, red and other 2 and 3-needled pines are susceptible to the killing of shoot tips and...
These fungi survive adverse conditions in leaves in the canopy and in fallen leaves. The spores they produce are wind...
Thrips, order Thysanoptera, are tiny, slender insects with fringed wings.
The privet rust mite, Aculus ligustri, is a microscopic mite with tiny, scissorlike mouthparts that it uses to puncture the...
Eriophyid mites are microscopic mites that often go undetected.
The black vine weevil is a serious pest in nurseries and established landscape plantings.
The rhododendron tip midge is a light-brown, 1.25-mm-long fly.
Twenty-eight lace bug species have been recorded in Pennsylvania, but only a few are key pests of ornamental evergreen plants...
The common roseslug, Endelomyia aethiops, can be found skeletonizing rose leaves in late spring and early summer.
Spider mites are tiny 8 legged animals closely related to spiders. Several kinds are important pests of ornamental trees, shrubs...
The European red mite (ERM) is the most important mite species attacking tree fruits in North America.
The rose midge, Dasineura rhodophaga (Coquillett, 1900), is an uncommon but damaging pest of roses.
An overview of the types of diseases that affect the Roses.
This insect has a global distribution, and is commonly seen on Rosa and Rubus.
This fungus readily attacks young expanding leaves and young canes.
Downy mildew is the common name for a group of highly specialized obligate parasites of vascular plants.
Unfortunately, the numerous insects and related pests that attack roses can make growing them "interesting," if not outright challenging.
Rose rosette disease has been spreading through much of the wild rose population of the Midwestern, Southern, and Eastern United...
Pear sawflies feed on hawthorn, serviceberry, pear, and other members of the rose family.
Cedar-apple rust and closely related diseases, cedar-quince, cedar-hawthorn, and Japanese apple rusts are caused by fungi belonging to the genus...
Blue and Norway spruces are susceptible to a branch killing disease caused by the fungus Cytospora kunzei.
The eastern spruce gall adelgid is a key pest of Norway spruce in northeastern United States.
Rhizosphaera needlecast disease is caused by the fungus Rhizosphaera kalkhoffii Bubak.
There are several species of sawflies that attack pines in Pennsylvania including the redheaded pine sawfly.
This scale is small and is often clustered in-groups of 3 to 8 at the base of new shoots. Their...
Prior to 1999, when Stigmina lautii was identified in North Carolina on blue spruce, this needle cast pathogen was only...
London plane and sycamore trees are susceptible to a fungus, Ceratocystis fimbriata f. sp. platani, that is lethal.
Lace bugs are exclusively plant feeders. The most common species occur on the foliage of trees and shrubs.
The tuliptree scale is one of the largest soft scale insects in the United States.
This pest has the potential to become a serious problem in nurseries and landscapes in Pennsylvania.
Symptoms include the branches and eventually the entire plant blackens at the base and dies.
Walnuts and hickories produce the chemical juglone (5 hydroxy-1,4- napthoquinone), which is exuded from all parts of the plant
Thousand cankers disease (TCD) is a disease complex native to the western United States.
Willow scab, caused by the fungus Venturia saliciperda, affects Salix species throughout Europe and the eastern United States.
Adults and larvae of the imported willow leaf beetle both feed on foliage of willows during the summer months.
Black canker of willow is caused by the fungus Glomerella miyabeana. In North America and Europe, the black canker pathogen...
Leafhoppers will feed on the new growth of wisteria. The severity of infestation depends on the size of the migrating...
Witchhazel blight is caused by a fungus, Phyllosticta hamamelidis. The fungus causes brown lesions bordered by darker brown margins.
The aphid produces raised ribs or "corrugations" on the upper leaf surface that match deep furrows between the veins on...
One of the more common scale insect pests seen in landscapes here in the Notheast is cottony taxus (cottony camelia)...
A small soft bodied insect covered with fine whitish wax, similar in appearance to soft scale.
English ivy, Hedera helix is an evergreen groundcover and climbing vine hardy in the Philadelphia area. Long utilized as a ground cover, the...
The Arboretum at Laurel Hill is collaborating with Cornell University to grow hybrid oak trees at their cemetery in Bala Cynwyd.
The project was...
Oak Wilt
Oak wilt has always been one of those diseases that we were happy to not have to deal with. We were aware...
