#prunicola scale

The Prunicola Scale, or Pseudaulacaspis prunicola, is a common pest that infests laurels, flowering cherry, lilac, holly, and privet trees. The insect causes damage such as yellowing or wilting leaves, stunted growth, and premature leaf drop. Prompt treatment by a professional certified arborist can preserve the health of your trees.

Physical Characteristics

Mature female white prunicola scale has protective shells that are circular and predominantly white, with a yellow center and they measure up to 1/16″ (1.5 mm) in diameter. Male covers are elongated and white, and they are typically the same size as the females. These covers serve as protective armor for scale insects.

Host Plants

White Prunicola Scale attacks various host plants, including cherry laurel (Prunus laurocerasus) and other Prunus species, such as flowering cherry. Additionally, populations of this scale may occur on the following species:

Lilac (Syringa)

Holly (Ilex)

Boxwood (Buxus)

Evergreen privet (Ligustrum)

Life Cycle of White Prunicola Scale

The White Prunicola Scale begins life as an egg, laid by adult females on the branches and leaves of various plants. These tiny eggs may be difficult to spot with the naked eye, but early detection is the key to preventing a potential infestation.

Egg-Laying Stage

The most common time for White Prunicola Scale to lay eggs is in the spring and early summer when conditions favor reproduction, but may vary depending on factors such as temperature and host plant health. The eggs are minuscule and whitish in color, typically on the stems and branches of infested plants. The eggs are often laid in clusters and are firmly attached to the plant surface, making them difficult to remove.

Crawler Stage

During this stage, the young scales, known as crawlers, emerge from their protective coverings to search for a suitable feeding site. The crawlers are tiny and nearly invisible to the naked eye. Part of what makes them difficult to spot is that their colors are usually translucent or pale yellow. The crawlers are highly mobile and active, and use piercing-sucking mouthparts to extract sap from the plant’s phloem tissue. This feeding provides the necessary nutrients for their growth but weakens the plant.

As the crawlers settle and establish themselves, they undergo a transformative process known as molting. The scale sheds outer skin during this stage, revealing a new protective layer underneath. After several molts, the White Prunicola Scale reaches the adult stage.

Adult Stage

The adult White Prunicola Scale insects are sedentary and do not have wings, making them dependent on their host plant for survival. Adults attach themselves to the plant’s stems, branches, and leaves, feeding by sucking sap from the plant. They may appear as small bumps or scales on the plant’s surface. Their feeding behavior further weakens the plant, causing stunted growth and yellowing leaves.

As the adult insects reproduce and lay eggs, the infestation can quickly spread, leading to more severe damage and an increased risk of secondary infections by fungi or bacteria.

Infestation Signs and Symptoms

Recognizing the signs and symptoms of white prunicola scale infestation is important. Leaf discoloration and dead branches are common indicators. Awareness of these signs allows for proactive monitoring and treatment to preserve the health of affected plants.

Leaf Discoloration

Leaf discoloration can result from infestation by the White Prunicola Scale. As noted, the scale pierces branches and stems with long, needle-like mouthparts. This process disrupts the flow of nutrients, causing deficiencies that ultimately cause leaf discoloration.

The leaves may develop yellow, mottled patches or appear pale and sickly. This discoloration occurs because the scale’s feeding deprives the plant of chlorophyll, which is needed for photosynthesis.

Dead Branches

White Prunicola Scale feeding can lead to stunted growth and an overall decline in plant health. As the insect depletes the plant’s resources, the branches can weaken and die back.

These signs can indicate a potential infestation and prompt homeowners to take proactive measures to address the issue.

Management Options

Several management options are available to homeowners when dealing with a white prunicola scale infestation.

Non-Chemical Options

Prevention: One critical non-chemical method for managing the White Prunicola Scale is to prevent infestations in the first place. Prevention is possible by regularly inspecting plants for signs of scale insects and promptly addressing any issues. Regular seasonal inspections by our plant health care professionals can help diagnose problems early. Additionally, avoiding overcrowding of plants and maintaining overall plant health can significantly reduce the risk of infestation.

Pruning: Pruning can be an effective non-chemical method for managing the White Prunicola Scale. A plant health care expert can prune infested plant parts and remove them to reduce the scale population and prevent the spread of the scale to other plants.

Washing techniques: Washing infested plants with a strong stream of water can help dislodge and remove scale insects from the plant surfaces. This method can be particularly effective for small infestations.

Horticultural oil application: Applying horticultural oil to the plants can suffocate and kill the scale insects.

Regular monitoring and early intervention are crucial for successful scale management and the overall health of the plants.

Chemical Options

Plant health care experts may recommend systemic insecticides targeting adult scales and nymphs. The plant absorbs these insecticides and circulates through its tissues, effectively targeting the scale population. Additionally, traditional bark spray insecticides may address visible symptoms and target the scale insects residing on the bark of the host plants.

Call Burkholder PHC for Pest Control

If you suspect your plants are affected by the White Prunicola Scale or other pests, seek professional assistance. Burkholder PHC provides expert pest management services for controlling white prunicola scale infestations and other common pests. Contact Burkholder PHC today to ensure the health and vitality of your landscape plants and trees.

Blog is originally published at: https://www.burkholderphc.com/prunicola-scale/