Damage and destruction caused by insects and diseases can severely limit a tree or shrub’s ability to manufacture the sugars and substances needed to remain healthy.
As a tree’s health suffers and declines, the odds for defoliation and death sharply increase.
A specialized program for trees and shrubs is the most logical step toward managing the spread of harmful insects and devastating diseases.
Diagnosis of Black Knot is fortunately an easy task, as the eye is easily drawn to the swelling knot known as a gall. As these galls grow and mature, they are able to spread the infection as they release spores. Branches with black knot must be removed in order to prevent the spread of the disease, however, it is important to be cautious with the removal of the branches as well as the tools used to prune them, as the disease can spread from both of these. Tools must be properly cleaned, and branches, properly disposed of.
Dutch elm disease is a vascular wilt disease. Early signs include the yellowing or wilting of leaves in a section of the tree. As the branch dies, the leaves turn brown. At this stage, while only a portion of the crown may be affected, this disease can spread rather quickly through the remainder of the tree, and death of the tree may be imminent. In some cases, the tree can linger for years in this condition as it dies. Trees infected later in the summer may survive longer. In the case of Dutch Elm, the earlier you start to treat the disease, the better. Untreated trees will die rapidly.
Needle Cast diseases cause spruce trees to shed or “cast off” their older needles and keep only the younger needles at the tips of the branches. It causes the tree to look as if it is dying, however it is treatable. It is a fungal disease it can be treated with fungicide.
Seiridium Canker disease is another fungal tree disease. It mostly affects Leyland and Italian cypress trees during long, hot, dry periods in the summer. It affects all ages and sizes of trees. It causes cankers to form on the stems, branches and in the branch axils (the upper angle between a leaf stalk or branch and the stem or trunk from which it is growing.) causing twig, branch or stem die-back. The cankers can appear purplish or brown and look like sunken patches on the bark. Branches or twigs destroyed by the fungus turn reddish brown in contrast with the dark green healthy foliage
Armillaria Root Rot is a root rot disease that starts in rotting oak and maple tree stumps and can spread to other trees via the root system. In an infected tree it can cause stunted leaves, the yellowing of needles and the die-back of twigs and branches. All host trees display symptoms of being infected by a white rotting fungus including light or bleached wood. This disease can be managed by a licensed tree expert by removing infected material.
Apple scab attacks both leaves and fruit of apple and ornamental crabapple trees. This fungal disease forms yellowed spots on the tops of the leaves and dark spots on the bottom of the leaves. These leaves may twist and wrinkle, and drop early in the summer. The fruit on the trees, as the name suggests, will get what look like scabs on the fruit. Steps should be taken to treat Apple scab both to save the tree, and to prevent the spread of the fungal spores to nearby trees.
Not all insects are harmful to the trees where they may reside. Some may even be helpful. Please check with a licensed tree expert before making a rash decision to remove a tree that appears to have an insect infestation. Also note that the following list is a brief overview of the types of insects that can harm your trees. There are many more where these came from, so it is important to check with an expert when you notice unusual insect activity in your trees.
The Emerald Ash Borer (Agrilus planipennis or EAB), originally from Asia, is believed to have migrated to North America by hitching a ride on wooden shipping pallets. It’s a small, shiny green beetle and is capable of destroying large ash trees.
The adult emerald ash borer beetles usually emerge in mid to late May (sometimes earlier if the weather is warm.) The larvae feed under the bark of the ash tree disrupting the plants ability to transport water and nutrients. An infestation is visible due to bark splitting and die-back. The presence of this beetle is threatening our entire Ash Tree population and could result in the complete extinction of Ash Trees. Please Report All Sightings of This Dangerous Beetle to the NJDEP.
Scale insects are the leeches of the plant world. They latch on to branches and feed on the sap of the tree. These insects can be difficult to spot at first because they latch on to branches and stay there. Without regular inspection of your branches, you may not notice the scale insects themselves until you have a large infestation. However, if you notice die-back or yellowing leaves on your trees, this is a good time to inspect the tree for this particular pest. Also, if you notice that parasitic wasps or ladybugs have moved into your trees, this may also be a sign that they have found one of their favorite snacks. (scale bugs) Scale infestations are important to address in order to maintain the health of your trees and the spread of the infestation.
Did you know that Gypsy Moths were actually spread to North America by a French scientist who was attempting to breed a hybrid silk spinning caterpillar that was less susceptible to disease? Unfortunately for millions of trees, this breed of caterpillar is hardy indeed, and is now considered one of the most destructive insects in the Eastern United States.
A gypsy moth infestation can cause partial defoliation, or complete defoliation of its host trees, which can starve a tree of essential sugars and carbohydrates leaving a tree weak and susceptible to disease, or may kill the tree entirely. A tree infested with Gypsy Moths may quickly become a tree hazard.
The asian longhorned beetle is wood boring insect that is native to China and Korea. It has since migrated to North America and has infested and killed hundreds of trees throughout the New Jersey area. This particularly nasty beetle goes after a variety of hardwood trees, however it seems to prefer Maples, Elms, Willows and Birches, which are all common in the Northeast.
They have a shiny black body with white spots, long antennae and are about 1 to 1 and a half inches long. They leave dime sized holes in trees. Trees infested by the Asian Longhorned Beetle must be removed before they become a breeding ground for more beetles.
Oak Wilt is a highly aggressive tree disease that affects all types of oak trees. One of the most susceptible is the NJ State Tree – the Red Oak. This fungal disease has been attacking trees in neighboring states, and if spread to NJ can cause significant harm to our tree population. If you see any of the signs of Oak Wilt, Please Alert the NJDEP immediately, and get a Licensed Tree Expert out to your location as quickly as possible to prevent the spread of the disease.
It’s symptoms commonly consist of discoloration of leaves, wilt, defoliation and the death of the tree.
Insects spread the disease-causing fungus from an infected tree to a healthy tree. Because the disease is also spread via root connections, replacement of a removed oak should not be attempted in the same location for some time. The disease is often managed by removing infected trees and breaking root connections with trenchers, hoes and rocksaws. Fungicide treatments are available to help thwart the spread of this disease.
