TREE CARE TIPS

An infestation of threatening insect found in Wyoming County

The Emerald Ash Borer (EAB), a highly invasive, wood-boring beetle known for killing ash trees and posing a threat to our state’s $25 billion hardwoods industry, has indeed infested a large population of trees near Forkston Township along Route 87 in Wyoming County. Jon Brown, owner of Brown Hill Tree Company and a nationally recognized arborist, came across the infestation a few weeks ago. As a result, it is more than likely this entire population of ash trees will be dead in three years. Forty-nine Pennsylvania counties have documented EAB infestations since it was first found in Butler County in 2007.

Emerald Ash Borer was first detected in the United States in Michigan in June 2002. Due to the sheer devastation caused by this pest, the U.S. Department of Agriculture (USDA) formed a national program almost immediately and provided cooperating states with resources for survey, outreach and management.

In Pennsylvania, a collaborative effort between the USDA, DCNR, U.S. Forest Service and Penn State University has been formed. The experts recommend that once an EAB infestation has been found, it’s imperative to start treating or removing ash trees in neighboring counties because of the insect’s ability to move quickly. EAB has also been detected in Susquehanna County near Montrose. In 2011, one was detected on a roadside sticky trap in Luzerne County near Harveys Lake. This summer, it is expected that many local ash trees will become infested with EAB.

Ash trees can be treated preemptively for EAB. “The preventative treatment has the best effect on the tree if done soon after the leaves emerge because the leaves help to spread the insecticides throughout the tree,” stated Jon Brown, ISA-certified arborist. However, if the tree is already infested, it will have to be evaluated before treatment can begin. If a tree dies, it becomes a safety hazard and liability for the homeowner who has the tree on his or her property or the municipality should it fall across a roadway.

“Within the past seven years, I’ve definitely noticed a growing rate of EAB infestations in Pennsylvania,” said Brown. “At Brown Hill Tree Company, we have the capability to treat ash trees prior to an EAB infestation, but I can’t stress enough how important it is to do this before an outbreak occurs. Individuals who have these trees located near their homes need to take this preventative step in order to keep their properties safe and their ash trees beautiful. If ash trees are left untreated, they might become extinct in PA within the next 10 to 20 years.”

EAB begins to emerge in mid-May, and its peak is mid-June. The transport of firewood is one activity that attributes to the spread of EAB and other invasive pests. This bright, metallic green insect is about ½” long with a flattened back. It has purple abdominal segments under its wing covers and can fit on the head of a penny. EAB is only found in ash trees, which are native to Pennsylvania. There is helpful information on the Brown Hill Tree Company website to help homeowners determine if they have an ash tree.

EAB is an insect that is hard to spot in the wild, but lots of woodpecker activity or water sprouts (suckers) originating from the trunk of a tree can help detect an EAB presence. EAB infest a tree by laying eggs in the bark. When the new offspring reach larva stage and tunnel beneath the bark is when the damage occurs.
This is not just a problem in Pennsylvania, but also nationwide. Ash trees have become nearly extinct in other areas of the country where EAB outbreaks have occurred, such as southeastern Michigan.

Emerald Ash Borer a threat to our Ash Trees

8 new counties in Pennsylvania had positive identifications of Emerald Ash Borer in 2012 bringing the total affected counties to 30!

The Emerald Ash Borer is a highly invasive, wood-boring beetle that kills ash trees
and poses a threat to the state’s $25 billion hardwoods industry.
This invasive insect is bright, metallic green, about 1/2″ long with a flattened back. It has purple abdominal segments under its wing covers. The EAB can fit on the head of a penny, and is hard to spot in the wild.

Typically EAB does not travel far on its own, but it can live in cut wood and it has spread across 14 states, because people have moved EAB-infested firewood.

Typically, the Emerald Ash Borer beetles will kill an ash tree within three years of
the initial infestation. Adults are dark green, one-half inch in length and one-eighth
inch wide, and fly only from early May until September. Larvae spend the rest of
the year beneath the bark of ash trees. When they emerge as adults, they leave D-shaped holes in the bark about one-eighth inch wide.

EAB Facts *It attacks only ash trees Fraxinus spp. *Adult Beetles are metallic green and about 1/2- inch long, and this small size makes them difficult to spot. *Adults leave a D-shaped exit hole in the bark when they emerge in spring. *Woodpeckers like EAB larvae; heavy woodpecker damage on ash trees may be a sign of infestation.

Homeowners may contact our tree care professionals to treat their trees. Our professionals have access to some products that are not available to homeowners.
it is important to weigh the decision to treat carefully. Consider the value of the tree in relation to treatment costs. Removal of a dead ash trees can range from hundreds to more than a thousand dollars.
Also consider the health of the tree. Research suggests that insecticide treatments may be able to save infested trees exhibiting low to moderate crown dieback (20 to 40 percent). When crown dieback is more extensive, there has been significant damage to the vascular system of the tree. This leaves the tree unable to have enough uptake of chemicals.
Treatments may be more effective if tree health is maintained. Therefore, it is important to fertilize trees in the late fall or early spring and water regularly, especially during periods of drought.

Hemlock Elongate Scale

Hemlock elongate scale

As if we weren’t challenged enough with trying to save our native hemlocks, the elongate hemlock scale is proving to be quite an adversary. Sometimes known as fiorinia scale, it is a serious armored scale pest of hemlocks and other conifers including spruce and fir. First observed in 1908, it is believed that this armored scale insect was unintentionally introduced into the United States from Japan.

The waxy covers of this species can be observed on the lower needle surface. The flattened, elongate, light yellow brown to brownish orange waxy cover of the adult female is about 1.5 mm long. The adult female’s body beneath the waxy cover, eggs, and crawler stage are yellow. The white, waxy cover of the male is smaller. Sometimes waxy secretions from settled crawlers may build into a mass of tangled strands. These waxy strands may be so abundant that it gives the lower surface of infested needles a white appearance. When this condition is present, it may cause uninformed individuals to misdiagnose this as hemlock woolly adelgid.

Outbreaks of elongate hemlock scale often intensify following infestations of hemlock woolly adelgid, drought, or other stresses that have weakened the trees. Stressed trees have less energy that lowers their ability to defend themselves. Therefore, maintaining trees in healthy condition will discourage the buildup of scale populations. For example, hemlock have shallow roots and are consequently susceptible to drought, so ornamental trees should be watered during dry periods. Sometimes well meaning people’s first response to a tree in trouble is to fertilize or spray a pesticide cocktail. However, applications of nitrogen fertilizer and broad-spectrum insecticides can exacerbate the pest problem.

Armored scale insects do not feed on the contents of vascular cells, therefore, the treatments for hemlock woolly adelgid are ineffective. These insects injure trees by inserting their threadlike, piercing mouthparts into needles and suck out vital nutrients and moisture. Frequently, this key pest is found on the same hemlock tree with hemlock woolly adelgid, Adelges tsugae . Trees turn off color, drop needles from the bottom up, and usually die within 10 years. These weakened trees are also more prone to wind throw (failure) during storms.

This species overwinters as fertilized females or eggs. In early spring the females deposit eggs beneath their waxy covers and may continue to lay eggs through early summer. Newly hatched scale insects are called crawler and do not have wax covering them while they disperse. Overlapping generations make spraying crawlers as management very difficult. Dispersal of crawlers over large distances usually occurs by wind currents or on the feet or plumage of birds or fir of animals. Crawlers settle on the underside of the needle, insert their mouthparts, and feed for about 8 weeks until maturity. Adult females may live up to one year.

Is my Tree an Ash?

Ash trees grow very large over time. They are often but not always found in damp areas. The bark becomes very rough and furrowed over time.

The leaves on an ash tree are what we call compound leaves. This means that an entire single leaf is actually made of many small leaflets. The picture shown is one ash leaf composed of several leaflets. This becomes noticeable when the leaves fall in the autumn. The entire leaf, composed of leaflets falls as one unit.

Branches on an ash tree are oppositely arranged on a branch. They emerge from a branch directly opposite from each other. Even the buds are directly opposite from each other.

Only true ash species Fraxinus spp. are affected by Emerald ash borer. Mountain Ash Sorbus spp. are not true ash and are not affected. These trees have clusters of orange berries which ash do not have. Mature Mountain Ash are usually much small than a true ash tree.