Discover the Elderberry Borer: Essential Facts for Gardeners

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Elderberry Borer is a fascinating insect that can both delight and affect gardeners. These beetles boast an attractive mix of metallic blue and orange coloring, but they are known to pose a challenge for those who cultivate elderberries. Developing an understanding of this insect can help gardeners better care for their plants and prevent damage caused by these beetles.

The Elderberry Borer (Desmocerus palliatus) primarily targets elderberry plants, as their common name suggests. Female beetles lay eggs near the base of the plant, and when the larvae hatch, they burrow into the stem, tunneling and eating their way into the roots. This behavior can weaken or even kill the affected elderberry plants, making them a concern for those who wish to grow and harvest the fruit.

Elderberries are popular for their dark purple berries, used in folk medicine and as a dietary supplement to treat colds and flu. Therefore, it is essential for those growing elderberries to be aware of the Elderberry Borer and how best to manage this intriguing fixture of the natural world.

Elderberry Borer Overview

Identification of the Borer Beetle

The Elderberry Borer, scientifically known as Desmocerus palliatus, is a beetle that belongs to the Cerambycidae family. This insect can be easily identified by its bright metallic blue body and yellow bands that resemble a wasp’s pattern. Some key features of the Elderberry Borer include:

  • Metallic blue and yellow coloration
  • Antennae with alternating black and yellow bands
  • Presence of well-developed wings

Life Cycle of the Elderberry Borer

The life cycle of the Elderberry Borer has four main stages: egg, larva, pupa, and adult beetle. Here’s a brief overview:

  1. Eggs: Female beetles lay their eggs near the base of elderberry plants.
  2. Larvae: After hatching, larvae burrow into the stem, tunneling and feeding on the plant’s roots.
  3. Pupae: The larva eventually becomes a pupa and, resembling a cocoon, undergoes metamorphosis within the plant stem.
  4. Adult beetles: The transformed adult beetles emerge from the stem and begin their search for a mate, thus starting a new cycle.

The Elderberry Borer is known to cause significant damage to elderberry plants by attacking the stems, which disrupts water and nutrient flow within the plant. To prevent or minimize damage, monitoring and early detection can play a crucial role.

Elderberry Plant Information

Characteristics of Elderberry Plants

Elderberry plants, belonging to the Sambucus genus, are deciduous woody plants ranging from clump-like shrubs to small trees. They typically have compound leaves with serrated edges and fragrant white or cream-colored flowers, which later develop into small berry clusters. Elderberry plants prefer moist, well-draining soil and partial to full sun exposure.

Some characteristics of elderberry plants include:

  • Deciduous nature
  • Compound leaves with serrated edges
  • Fragrant white or cream-colored flowers
  • Small berry clusters

Types of Elderberries

The two commonly known species of elderberries are Sambucus nigra (European black elder) and Sambucus canadensis (American elderberry).

Feature Sambucus nigra Sambucus canadensis
Height Up to 20 feet Up to 8-10 feet
Growth Small tree form Shrub-like form
Use Ornamental and medicinal Edible fruit, medicinal, and wildlife habitat

Sambucus nigra typically grows into a small tree, reaching heights of up to 20 feet, whereas Sambucus canadensis remains more shrub-like, growing up to 8-10 feet high. Both species are valued for their various uses, such as ornamental, medicinal, and edible fruit, as well as providing habitat for wildlife. There are also numerous elderberry cultivars available, which offer different sizes, fruit flavors, and resistance to diseases.

Infestation Signs and Symptoms

Wilting Leaves and Canes

Elderberry borer infestations cause various signs and symptoms on elderberry plants. Wilting leaves and canes are common indicators of an infestation. This might happen due to the larvae feeding on the wood, which disrupts the flow of water and nutrients throughout the plant. A few examples of wilting include:

  • Leaves turning yellow and drooping
  • Canes becoming weak and bending

Discolored Lenticels

Discolored lenticels are another sign of elderberry borer infestation. Lenticels are small pores on the surface of the stems and branches, essential for gas exchange. An infested plant may show:

  • Dark, discolored patches on lenticels
  • Swollen, damaged lenticels

Comparison Table: Wilting Leaves vs. Discolored Lenticels

Sign Wilting Leaves and Canes Discolored Lenticels
Appearance Yellow, drooping leaves Dark patches
Causes Larvae feeding on wood Borer damage
Effect on Plant Reduced water flow Hindered gas exchange

In conclusion, if you notice wilting leaves, canes, or discolored lenticels on your elderberry plants, it might be a sign of elderberry borer infestation. To maintain the health of your plants and ensure a good fruit yield, it’s essential to address these symptoms early on.

Damage and Impact on Elderberry Plants

Effect on Flower and Fruit Production

Elderberry plants produce flowers called cymes, which later develop into berries. The Elderberry Borer is a beetle (Desmocerus palliates) that lays its eggs near the base of the Elderberry plant. When the larvae hatch, they burrow into the plant and cause damage. This damage can result in:

  • Reduced flower production
  • Smaller fruit yield
  • Lower quality berries

The impact on flower and fruit production is especially concerning in the plant’s first year, where it is important to encourage root system development. One way to do this is by removing all flowers from the plants in their first year.

Impact on Plant Health and Growth

Elderberry Borer infestation can affect the health and growth of the plant in several ways:

  • Damaged and weakened stems
  • Increased susceptibility to diseases
  • Reduced overall plant growth

One key aspect in maintaining healthy Elderberry plants is providing 1 to 2 inches of water per week and ensuring they are grown in a well-prepared soil with a pH between 5.5 and 6.5. For example, adding mulch around the base can help retain moisture and provide a better growing environment for the plant.

Furthermore, removing perennial weeds from the planting area can reduce competition for nutrients and water, which ultimately benefits plant health.

If you suspect an Elderberry Borer infestation, monitor the plants for visible damage or symptoms and consider applying products labeled for control of common pests on elderberries, such as organic options before leaf curl occurs. Always follow label instructions and make sure they are suitable for your specific growing conditions to ensure optimal plant health and growth.

Elderberry Borer Control and Prevention

Cultural Practices for Borer Control

  • Planting: Choose healthy, disease-free plants for planting to reduce the likelihood of attracting elderberry borers.
  • Pruning: Regularly prune dead, damaged, or infected elderberry stems to prevent borers from establishing a home. Remove pruned material from the area.
  • Water and Nutrient Management: Provide 1-2 inches of water per week and balanced nutrients to ensure healthy plants that can better withstand pests like elderberry borers1.

Chemical Treatment Options

Some chemical treatments are available for control of common pests on elderberry. Always follow label directions and restrictions when using chemical treatments.

Example of a chemical treatment:

  • Product: Abound
  • Application Rate: 6 to 15.5 fl. oz. per acre2

Natural Enemies of the Elderberry Borer

Several natural enemies help to control elderberry borer populations:

  • Parasitic wasps: These wasps lay their eggs inside the borer larvae, eventually killing them.
  • Birds: Woodpeckers, for example, feed on elderberry borer larvae found within the stems of the plant.

Comparison of Elderberry Borer Control Methods

Control Method Pros Cons
Cultural Practices Non-chemical, sustainable Requires regular maintenance
Chemical Treatments Can be effective Possible negative side-effects, may harm beneficial insects
Natural Enemies Environmentally friendly Unpredictable, less controlled approach

Bug Control Recommendation Tool

What type of pest are you dealing with?

How severe is the infestation?

Do you require child/pet/garden safe treatments (organic)?

Are you willing to monitor and maintain the treatment yourself?


Additional Considerations

Toxicity of Elderberry Plant Parts

Elderberry plants are known to contain toxic compounds called cyanogenic glycosides, particularly in their leaves, stems, and seeds. Consumption of these plant parts may lead to adverse health effects, such as nausea, vomiting, and diarrhea. Here are some key points to consider:

  • Toxic parts: Leaves, stems, and seeds
  • Symptoms: Nausea, vomiting, diarrhea

However, elderberries themselves are safe to consume when cooked, and they offer numerous health benefits.

Role of Birds in Elderberry Borer Ecology

Elderberry borers (Desmocerus palliatus) are a type of beetle that infests elderberry plants. Their larvae burrow into the plant’s stems and roots, causing damage and reduced vitality. Interestingly, birds play a significant role in the elderberry borer’s life cycle. They serve as natural predators and help control the beetle population by feeding on them.

For example, insectivorous birds like woodpeckers and chickadees can feed on larvae or adult beetles, which in turn aid in maintaining a balanced elderberry borer population. Here is a comparison of two common bird types that consume elderberry borers:

Bird species Primary diet Relationship with elderberry borer
Woodpeckers Insects, seeds Predators of elderberry borer
Chickadees Insects, seeds Predators of elderberry borer

In conclusion, understanding the toxicity of elderberry plant parts and the role of birds in elderberry borer ecology is crucial to ensure safe consumption and efficient management of elderberry plants in your garden.

Footnotes

  1. Elderberry – West Virginia University ↩
  2. Elderberry Insect and Disease Management – MU Extension ↩

 

 

 

 

 

 

 

 

 

 

 

Authors

  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

    View all posts
  • Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

    View all posts
Tags: Elderberry Borer

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7 Comments. Leave new

  • Hi!
    I found one of these in my backyard today too. I’m in St. John’s, Newfoundland Canada as well. What part of town are you in? I’m in Cowan Heights and my yard backs onto the river.
    denise 🙂

    Reply
  • I saw these large, lovely beetles for the first time last June in a remote, sparsely populated area in western, Winchester, CT, though I work as a field ecologist all over Connecticut, and see elderberry all the time. Are the adults out only for a brief window perhaps? Or Is Desmocerus palliatus declining? If so, why? Has anyone looked into this? Attracted to outdoor lighting, maybe? Pollution-related issues detecting the pheronomes emitted by females in the stems? Elderberry populations too fragmented? Are the leaves distorted due to the interior stem damage? Are you sure the adults do not nibble somewhat on the foliage? Something else: I have noticed that winter kill is very common in common elderberry in CT. Is this perhaps the result of stem borer damage? I do have sharp photos showing distorted, slightly bitten leaves if anyone is interested.

    Reply
    • According to BugGuide, the Elderberry Borer is “uncommon” and “Adults feed on pollen, found on flowers, especially those of elderberry.” There is no mention of the adult Elderberry Beetle eating leaves.

      Reply
  • I have them in my house even the cupboard. Please advise. Thanks

    Reply
  • I found this bug at my camp it was at Newfoundland bay Roberts Thanks for the advice I hope that that bug lives long

    Reply
  • We cut down a eucalyptus tree last year. We are keeping the wood to burn in our fire place. We just noticed small bored holes in many of the cut pieces. The is a very fine sawdust under the bark. We saw small black beetle looking insect that looks like the horned powder beetle. We have not seen them alive, only a few dead ones. Do you think it is safe to burn the wood? thank you. William

    Reply

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