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  • Dutch Elm Disease of Trees

    … and once the infection reaches the trunk the entire tree may wilt. In older trees, wilt symptoms may progress … show vascular streaking under the bark. American elm tree showing typical flagging and dieback symptoms due to …

  • Cherry Shot Hole Disease

    … leaf spot caused by the fungus Blumeriella jaapii. Both diseases are favored by warm, wet spring weather. Cherry leaf … drops out, leaving small “shot holes.” Infected cherry tree leaves will turn completely yellow and drop from the … pressure is high, but it is not lethal to the plant if the tree is otherwise healthy. On cherry laurel shrubs , the …

  • Why Oak Trees are Declining or Dying

    … :  Joseph OBrien, USDA Forest Service, Bugwood.org Common diseases of oak trees Two common leaf diseases of oaks in Maryland are oak anthracnose and … blocks the water and nutrient “circulatory system” of the tree.  Importantly, oak wilt is not known to exist in most …

  • Anthracnose Diseases of Shade Trees

    … Bugwood.org Updated: May 25, 2023 Key points Anthracnose diseases are characterized by discrete lesions that are … the entire leaf.  This is an early-season disease and many tree species like sycamore will develop new foliage to … conditions (cool, wet, rainy spring weather), the entire tree may be defoliated in the spring or early summer. …

  • Conifer Bark Beetles on Trees and Shrubs

    … pheromone, which attracts more bark beetles to the tree under attack. Beetles often carry pathogenic fungi such … stain that are deposited in the vascular system of the tree. These fungi quickly multiply and clog the water … frontalis ) Southern pine beetle adult. Photo:  Pest and Diseases Image Library , Bugwood.org Southern pine beetle …

  • FAQs: Plant and Insect Identification

    … Department of Agriculture's Gypsy Moth Program . What does poison ivy look like? How can you tell it from Virginia creeper in the winter? Poison ivy has three leaves. The University of …

  • Key to Common Problems of Dogwoods

    … dogwood (Cornus florida) is a relatively small flowering tree that is popular in Maryland home landscapes. Although it is a  native species, it is susceptible to several diseases, pests, and abiotic (nonliving) problems that can … uptake by the roots.  Leaf scorch alone rarely kills a tree but it can weaken the tree or can make it more …

  • What's Wrong with my Colorado Blue Spruce Tree?

    … attractive color and shape. There are, however, two plant diseases that commonly infect and disfigure them. Both … and progressively speed up the decline of this popular tree. Rhizosphaeria needle blight on blue spruce. Needle Cast … symptoms will continue to spread upward and around the tree. Branches will decline and die after 3-4 years of …

  • Fire Blight Disease of Trees

  • Beech Bark Disease

    … faginata  and  Neonectria ditissima ) to enter the tree, ultimately stunting and killing it. In some forest … MISC December Invader of the Month. Scale infected beech tree   Photo: PA Depart. of Conservation and Natural … wax coating. This will occur on the trunk and limbs of the tree in scattered groups that will later become large strips …