Author: Burkholder PHC

Invasive species are plants or animals from another region that have been placed in a new environment. Often these species are introduced to an area by humans and can spread quickly and cause damage to native ecosystems and people. While not all invasive species are necessarily dangerous or lethal, some of these plants and animals can disrupt the balance in their new environments.

Invasive species have traits that allow them to thrive and spread over their new environment rapidly. Some of these include

• Ability to grow quickly
• Ability to reproduce quickly
• Ability to disperse a high number of seeds or spores quickly
• Ability to alter form to suit current conditions
• Tolerance of a wide range of environmental conditions
• Ability to sustain a diet of various food types

Invasive species are often overlooked because those unfamiliar with these plants and animals do not perceive them as threatening. However, these plants will take over large areas of land over time. A well-known example of an invasive plant is the kudzu vine (Pueraria lobata). Kudzu was brought from Asia into the United States as a food crop during the late 19th century. The vine spread throughout many southern states in the U.S. and chokes out surrounding plant life.

Invasive species can be challenging to remove once established. One of the reasons is the lack of natural control mechanisms. In their native environment, plants and animals have predators or environmental factors that act as control mechanisms to keep populations in check.

For example, the spotted lanternfly is an invasive species of planthoppers native to China. In China, the lanternfly is preyed upon by native species of wasps. However, those wasps are not found in Pennsylvania, so the spotted lanternfly has spread rapidly because those predators are unavailable to keep the population in check.

The most common way invasive plants spread is by being sold at nurseries. In some cases, many invasive plants often lack labeling that indicates whether the plant is native or exotic to a specific region. As a result, governments are taking more action to prevent certain invasive species from being sold at nurseries.

If you are purchasing plants for your landscape, you may wish to check to see whether the plant is native or could have negative impacts on your landscape. If you are concerned about invasive species of plants and insects on your property, contact plant health care experts to assist with removal efforts.

Invasive species are difficult to remove, as removing or controlling their population requires extensive knowledge of the specific species and the various control and removal methods. These methods also have to protect the health of other plants in the environment.

Invasive species can threaten local ecosystems, and some have the potential to cause harm to native wildlife and people. Visit next month as we continue our series and discuss invasive plants. Burkholder PHC has experience helping homeowners in the Main Line area with all types of plants and insects. We have a team of specialists who will visit your property, conduct a plant health care evaluation, diagnose the problems, and inform you of the recommended treatment options. Contact us today for a free consultation.

The trend of the past 10 years in residential landscapes has been increasing pressure from insect pests, diseases, and vertebrates. We fully expect that this will continue in 2023 and that the plant health care outlook for the next year will include the following conditions.

1. Increase of insect pest number and variety that will affect more ornamental plants
2. A wet spring will bring increased soil and foliar disease pressure
3. Damage from deer will certainly continue to increase for the foreseeable future

In addition, we are just about due for the next invasive landscape pest, following emerald ash borer (1992), brown marmorated stink bug (2001), and spotted lanternfly (2014). Investing in a program to manage the biological health of landscape plants and keep soil in good shape is the best way to ensure your landscape not only survives, but thrives. Burkholder Plant Health Care offers a broad variety of programs to control insects and diseases that are damaging plants, vertebrate pests that are eating investments, and bugs that bite, sting, and transmit diseases to people and pets.

Burkholder PHC’s manager, Starker Wright, has been busy in the field. His work, extensive research and education, and his vast experience have led to the following achievements.

• First identification of crape myrtle bark scale in Pennsylvania (West Chester), confirmed by Penn State Insect ID Lab.
• Federal quarantine identification of white rust on chrysanthemum (Berwyn), confirmed by USDA-APHIS.
• First identification of camphor shot borer damage in hemlocks (Phoenixville), confirmed by Penn State Insect ID Lab.
• First active sampling program in Pennsylvania for vascular streak dieback disease in redbud.
• Submission of field research article “Pre-Emergent Control of Spotted Lanternfly” in collaboration with Bartlett Tree Experts.
• Continuing research with Bartlett Tree Experts and University of Maryland on potential impact of native predators on spotted lanternfly eggs.

On January 10th, Burning Bush (Winged Euonymus, Euonymus alatus) and four species of privet (Japanese, Border, Chinese, and Common) will be added to the list of invasive plants that will no longer be allowed to be grown for sale in Pennsylvania (https://www.agriculture.pa.gov).

These plants will join Callery (Bradford) Pear and Japanese Barberry on the Pennsylvania Controlled Plant and Noxious Weeds List, overseen by the Pennsylvania Department of Agriculture’s Controlled Plant and Noxious Weed Committee (CPNWC). Many other plants are still under consideration to be banned, based on recommendations by the Pennsylvania Governor’s Invasive Species Council (PISC). The current candidate list can be seen at https://www.plna.com/news/581035/Invasive-Species-Council-Recommends-List-of-25-Plant-Genera-to-Be-Banned.htm.

In Pennsylvania, a noxious plant is “identified as a plant that is determined to be injurious to public health, crops, livestock, agricultural land or other property and cannot be sold, transported, planted, or otherwise propagated in Pennsylvania”.

Every plant that leaves the property of Burkholder Landscaping and Sauder’s Nursery has been proactively monitored and treated to minimize spread insect and disease pests. This does not guarantee that once installed, infestations will not happen, but it does greatly reduce the risk of spreading damaging plant pests.

Now you know what to expect with regard to the plant health care outlook for the coming year, and the information could help you recognize issues in your own yard. Burkholder PHC’s team of experienced, qualified arborists will visit your property, conduct a plant health care evaluation, diagnose the problems, and inform you of the recommended treatment options. In addition, we provide a proactive approach, helping encourage and maintain your trees’ health and appearance. Contact us today for a free consultation.

Mosquitoes have long been considered summertime pests. You know that mosquitoes are annoying with their high-pitched buzzing on hot summer nights, and that their bites lead to itchy skin. Did you know that these insects pose health risks to animals and people? Mosquitoes are actually a major risk to human and animal health. Mosquito borne diseases are spread through their bites, which can cause sickness and death in both humans and animals.

Bites from mosquitoes cause itchy skin and welts in most humans, resulting from the immune system releasing histamine when the mosquito breaks the skin. Though mosquitoes consume nectar for energy to fly, females need a blood meal to nourish developing eggs. These female mosquitoes are attracted by carbon dioxide, so humans and animals are perfect targets. Mosquitoes are also likely to fly in groups, so a person can receive multiple bites in a short time.

These pests carry numerous risks for humans and animals during their active times. They are typically not active when temperatures drop below 50 degrees.

Mosquitoes are a risk to human health in the United States, particularly during the summer months. The Centers for Disease Control and Prevention (CDC) reports that there are about 3,000 deaths in the United States each year from mosquito-borne diseases, including:

• Zika virus
• West Nile virus
• Eastern equine encephalitis

With their fur, you might think that animals would be protected from mosquito bites. However, they are at risk of health problems from mosquito bites too. Mosquitoes transmit heartworm disease, which can be fatal to dogs, cats and horses.

You can protect your animals in a few ways:

1. Use a heartworm preventative that kills mosquitoes. The heartworm preventative you use also kills other blood-feeding insects such as ticks and fleas.
2. Keep your pet indoors at dawn and dusk when mosquitoes are most active.

Use insect repellents for dogs such as spot-on treatments (Frontline Shield, Advantix II) or natural sprays (Wondercide, Vet’s Best). Repellents intended for humans (especially those containing DEET) are not recommended for use on animals.

The best way to prevent these diseases is to reduce the number of mosquitoes in your landscape using Integrated Pest Management (IPM).

Integrated Pest Management (IPM) is a pest management strategy that combines common-sense practices and ecological concepts to reduce pest populations. These practices include:

• Pesticide application when necessary
• Prevention of pests by exclusion, sanitation, and other non-chemical means; and if pesticides are used, choosing the least toxic one for the situation at hand
• Monitoring for insect population trends so appropriate pesticides can be applied only when needed

IPM’s holistic plant health care and pest management helps create and maintain conditions ideal for a landscape’s health and minimize pests’ presence and effect.

What are the ways to treat mosquitoes in your landscape?

Plant health care professionals may use insecticides to treat pests in a home landscape. Insecticides are most effective against immature mosquitoes when applied to areas where water collects, such as around the foundation of a house and near fish ponds or birdbaths that hold water for long periods. For control of adult mosquitoes, we recommend treatment of mosquito resting and mating sites (such as plant material) up to 6 feet high around the boundary of a property or landscape feature such as a deck, patio, or pool. For consistent control of adult mosquitoes, treatments should be reapplied monthly through the peak season of mosquito activity.

Repellents can be sprayed on plants as a preventive measure against mosquitoes.

Some natural predators feed on mosquito larvae in water bodies, including dragonflies, damselflies, and backswimmers. Unfortunately, these predators fail to survive long enough after hatching to effectively control populations for more than one generation unless abundant food is available for them all year round. Each generation of mosquito adults generally only mates once, and males die within about 2 weeks of mating. Females can live for a month or more, may lay up to 10 batches of eggs (50 to 500 per batch), and will continue to feed on blood throughout their lives.

You can also use barriers like mesh screens across doorways leading outside or window screens over windows that open onto balconies or porches where people spend time outdoors during evenings. The barriers can help keep pests from entering your house.

Eliminating standing water is an effective method of reducing mosquito populations since water is required for mosquito eggs to hatch. This practice is referred to as source reduction. Examples include old tires, buckets, flower vases, abandoned toys, and other items that collect rainwater in shady areas of your yard. If you have a pool or pond in your yard, ensure proper maintenance to prevent algae and mosquito-friendly plants such as cattails from growing.

Mosquitoes can pose significant risks to human health. We would recommend a professional evaluation to determine if your property is infested with or at risk of infestation with these pests. Our evaluation is free, and proper treatments can restore your landscape’s health. Contact Burkholder PHC today for a free consultation.

In May of 2021, we began seeing darkened stems and black moldy growth on crape myrtles in Chester County, carrying over from an insect infestation in the fall of 2020. To recognize that these symptoms were not caused by crape myrtle aphids (common), samples were collected and submitted to the Insect Diagnostic Laboratory at Penn State. These samples revealed the first recorded incidence of crape myrtle bark scale (CMBS) in the state of Pennsylvania. This spring, calls regarding damaged crape myrtles have become much more common, and diagnosis is almost always this insect, which we have now also found in Delaware County. This is bad news for Pennsylvania’s crape myrtles, one of the most ubiquitous and attractive flowering plants in the landscape.

Crape myrtle bark scale is an invasive insect introduced to the United States from Asia in the early 2000s. The insect was initially collected and confirmed near Dallas, Texas in 2004, and detections have slowly moved eastward across southern states, with detection in Arkansas in 2013, North Carolina in 2018, and Maryland in 2020. This insect has been detected in 18 states (including DC), and the Pennsylvania infestation is the northernmost detection to date.

Initial models suggested that this insect would not move north of USDA Growing Region/Plant Hardiness Zone 8 (coastal Virginia and North Carolina); however, the Philadelphia area is precisely aligned with Beijing, China (~40o N Latitude), which is the northernmost range of this insect in its native land. Likely, this pest can survive in any geographic region where crape myrtles are a realistic landscape option; as winter hardiness is bred into crape myrtles, both the plant and the bug will move further north. In general, low temperatures will kill the tree before killing the pest, which can survive through winter at any life stage, from egg to adult.

Crape myrtle bark scale (CMBS) is a serious, direct, and primary pest of crape myrtles; however, an infestation of this pest alone will rarely kill trees outright. Instead, damage to crape myrtles is most commonly seen as the development of black sooty mold on the bark and leaves of the tree, and black sooty mold is just what it sounds like: a gray to black moldy growth covering leaves and bark.

Aside from the aesthetic problems of having ornamental trees turn black, heavy infestation with CMBS will delay foliar emergence (leaf-out) in spring and can severely limit flower growth (up to 70% loss of blossoms). In addition, the black sooty mold is growing on the insect’s excrement, which is very high in sugars and commonly attracts masses of unwelcome stinging insects such as wasps and hornets. This phenomenon is similar to what one sees locally, accompanying high infestations of spotted lanternflies on maples, willows, styrax, and ailanthus.

Trees suspected of infestation by Crape Myrtle Bark Scale can be confirmed quickly since this scale is the only bark scale active on crape myrtles and is one of only two direct pests that produce black sooty mold on these trees.

The most common symptom of an infestation is a general darkening of the bark, which can be seen in spring, especially when infested trees are close to uninfested trees. Closer examination will reveal clusters of white bumps or tufts, which are the silken sacs that the bugs have spun to either:

• Lay eggs in and die (adult females), or
• Protect themselves during metamorphosis (males)

Looking even closer, the individual insects (eggs, nymphs, pupae, and adults) are bright pink, and smashing the white silken bumps with a fingernail produces a blob of dark pink goo.

With large numbers of CMBS, the presence of these insects on trees is very clear; however, with newer or smaller infestations, most signs will be seen in the following:

1. At pruning cuts
2. In branch unions
3. On the underside of upper branches

A correlation between trees growing in the shade and more significant CMBS damage has been found, meaning that trees in full sun are either less prone to infestation or damage is less pronounced in full-sun trees. According to preliminary data taken in Texas, significant differences exist in the rate or density of infestation by various crape myrtle. The data found no varieties to be resistant to CMBS. However, some were worse than others, and CMBS has been found to infest all types of crape myrtle available in USDA Zone 6 (most of Pennsylvania).

Through most of the range of CMBS in the United States, this insect has 2-3 generations per year, and in the northern edge of the known range (Pennsylvania), the hypothesis is that only 1-2 generations will form, given the shorter growing season. Each generation takes 3-4 months to complete development (from adult to adult). However, the number of generations in any particular area can be challenging to determine since all life stages are capable of overwintering.

Newly hatched eggs (for scale insects, this stage is known as crawlers) are the most mobile and most vulnerable life stage. Therefore, most chemical control products recommend treatment to coincide with egg hatch/crawler activity. Eggs are most likely to hatch after about 10 days at or near 80oF, and in the Philadelphia area, we expect that egg hatch will occur in late May or early June (~650-750 degree days).

In its native range (China, Japan, and Korea), CMBS has reported many plants of economic importance, including apple, soybean, blackberry, and Korean boxwood. However, this pest is most associated in Asia with crape myrtle, persimmon, and pomegranate. In trials done in the US, CMBS has been found on 5 plants reported from Asia, aside from crape myrtle. Plants on which CMBS has been found in the US include St. John’s wort, American beautyberry, and recently spirea.

With invasive pests of landscape plants, population levels and damage can be explosive, and early detection is the key to effective management. Many strategies are available to manage this insect pest, from biological control agents (releasing of the pest’s natural enemies, ladybugs) to chemical controls (systemic insecticides or topical treatments). However, none will be as effective as is possible with the identification of the problem before damage becomes irreversible.

Crape Myrtle Bark Scale can be challenging to control due to their behavior and physiology. If crape myrtles are a signature species of your landscape, or if you have trees that appear to be declining, send us an email or give us a call and we will come out and conduct a plant health care evaluation, diagnose the problems, and let you know what your treatment options are. Burkholder PHC provides no cost identification of the problem in addition to free testing, diagnostics, inspections, and evaluations. Contact us today for a free consultation.