Friday, November 20, 2015

English Ivy - Hedera helix

Though it is thought to be a beautiful plant by many (myself included), English Ivy- Hedera helix is a very invasive plant in our area and can cause severe damage to properties and even death to the trees it grows on without proper management. English Ivy vines quickly and easily take over areas that are cleared/disturbed, woods lines, brick work, trellises, garden areas, and even tree trunks / canopies. Ivy can decimate the natural ecosystem by girdling out mature trees and other plantings and overtaking native ground coverings. It is native to Europe, Western Asia and Northern Africa and was introduced to the United States by European immigrants. Common uses as an ornamental vine, landscape buffer, ground cover and climbing vine have all made English Ivy very popular. Over the past couple decades English Ivy has spread from a simple ornamental vine to a naturalized (and very invasive) vine in 18 of The Unites States including Maryland.

Image Citation (Ivy): James H. Miller, USDA Forest Service, Bugwood.org

English Ivy is an evergreen vine (one of it's very attractive features) that is a member of the Ginseng family (Araliaceae). It is a creeping or climbing vine that can grown at height of over 90 feet if given the opportunity or structure to adhere too. The leaves are leathery or waxy in appearance, generally having five points in a palmate (hand) shape. They are a deep green in color when young with white veining, lightening in color with age. When mature the leaves produce a pale greenish-yellow flower in the fall season. Once the vine enters a forest it quickly overtakes the native vegetation and prevents them from regenerating, it also interferes with the ecosystem by altering food sources and habitat for wildlife this is by far it's biggest downfall. The vine attaches itself to structures and trees by small hairlike roots, when on a mature tree it can kill it and cause the tree below to die, sometimes rapidly. On brickwork, grouted or mortared surfaces it can easily break through the material causing problems that often times can not be seen due to the vines coverage.

Image Citation (Ivy Infestation) David J. Moorhead, University of Georgia, Bugwood.org

The fruit of English Ivy is a black-purple color with three stone textured seeds inside. This fruit is only eaten in small amounts by wildlife as they carry a slight toxicity. When humans ingest the fruits it can cause severe discomfort which is often combined with, diarrhea, nausea, upset stomach, fever, or even the onset of a coma. Rash may also occur in persons with sensitive skin after direct contact with the leaves and/or sap.

Image Citation (Ivy overtaking tree): Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Control of English Ivy is often ongoing and intense. You can manually, mechanically or even chemically remove or address the infestation. With small areas control is much easier, larger more established areas often require a combination of all three methods to truly eliminate the growth. If any roots remain in an area they will likely re-sprout throughout the season. Mulching is another method to help control/eliminate new growth on ground areas, by covering the ivy with a thick layer of mulch continuously over two full growing seasons you can kill the vine. Very large growths often required the use of herbicides often on a continuous basis until the growth is fully eradicated. Tree climbing vines can be cut at ground level prior to applying herbicide to the rooted section of the vine as well as the ground level leaves. Generally the first attempt at controlling or eradicating English Ivy is not successful by any single method.

Yes, it is beautiful but it should never be a recommended planting in landscapes or gardens in our area. If you must have English Ivy in your gardens do so in a container where you can trim it frequently and absolutely prevent the roots from spreading. This type of Ivy is best suited as a houseplant in our area!

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Wednesday, November 4, 2015

The Asian Longhorned Beetle - Anoplophora glabripennis

The Asian Longhorned Beetle - Anoplophora glabripennis (ALB) is a serious pest from China, it has made it's way to the United States and has been observed attacking our trees. This beetle's larvae tunnels into trees, causes girdling of stems and roots, repeated attacks can lead to die back usually beginning with the crown of the tree and eventually the entire tree. It is thought that the Asian Longhorned Beetle traveled to the United States inside solid wood type packaging material from China, it has been intercepted at various ports through the country. Within the United States it appears that this beetle prefers trees in the Maple species (Acer), such as Red, Norway, Silver and Sugar Maples and Box Elders. They have also been found on Birches, Buckeyes, Horse chestnut, Willows and Elms.

Photo Citation (Infestation/Tree Damage) Dennis Haugen, USDA Forest Service, Bugwood.org

Photo Citation (Adult ALB) Peggy Greb, USDA Agricultural Research Service, Bugwood.org

The ALB are unique in appearance and quite easy to spot. Adults have a deep black bodies with white spots on the back. They are 3/4 - 1 1/4 inches long and have very long antennae that are usually 1 1/2 - 2 1/2 times the actual length of their bodies. The antennae are clearly marked by white bands or stripes on each segment. The egg laying sites within a trees bark is generally oval or round and are chewed out by the female beetle before she deposits a single egg into each. Some trees- Maples most notably, will ooze sap from the egg laying sites as the larvae feed inside during the summer months. Around the base of infested trees there will be an accumulation of coarse sawdust usually found at the point where the branches meet the trunk, this sawdust is caused from the larvae boring into the tree, stems and branches. When the adult ALB finally exits the tree it leaves a large round hole that is about 3/8 of an inch in diameter on branches or trunks. ALB only have one generation per year and adult beetles are usually only found from July - October. A female can only lay 35- 90 eggs in her entire lifetime and eggs can hatch in 10-15 days. The larvae will live under the bark and continue to feed within the tissues of the tree, they then bore deep into the tree to pupate. The adults emerge from pupation sites by boring tunnels in the wood and creating round exit holes.

Photo Citation (Entrance and Exit Wounds) Dennis Haugen, USDA Forest Service, Bugwood.org

Currently in the United States the only way to eliminate the pest is to remove infested trees and destroy them by chipping or burning of the material. There are many quarantines in effect around the country to help prevent further spread of the insect (and other insects). As with most pests early detection is the best defense allowing for rapid treatment/removal, this is the only way the pest can be truly eradicated from an area.

If you suspect that the Asian Longhorned Beetle is in your area it is asked that you collect an adult beetle in a jar and immediately notify officials in your area. You can contact your State Department of Agriculture, Forest Service, State Forester, Department of Natural Resources, or State Entomologist. You can also call toll free to 1(866)-702-9938 . To learn more about the ALB you can visit: www.na.fs.fed.us/fhp/alb/  or  www.aphis.usda.gov/plant_health/plant_pest_info/asian_lhb/index.shtml

Meet More Trees and learn about their pests on our website www.ArundelTreeService.com  or our blog  www.MeetATree.com