Not known to transmit any human or animal pathogens.

Honeydew (a liquid secretion from C. japonicus) supports the growth of black sooty mold on host plants.

Signs are similar to those of other wax scales (Coccidae) and are a consequence of adult and nymphal feeding on the phloem. 

Signs of infestation include:

• Reduced plant vigor, which, in heavy infestations, may result in chlorotic spotting, premature shedding of leaves, wilting, and stem dieback. 
• Presence of honeydew, which may cause leaves and stems of the host to appear glossy or moist.
• Black sooty mold that looks like a crust over any part plant where honeydew is present (See the Pest Datasheet for image).
• The presence of foraging bees, wasps, hornets, and ants could indicate the presence of wax scales, as the honeydew attracts them.

A Likelihood of Establishment Map is now available. This survey should only be considered in the states with appropriate conditions and suitable hosts for this insect. The map was produced by the SAFARIS Team. SAFARIS is a modeling framework that enables PPQ to quickly respond to emergencies, efficiently survey for pests, and assess potential pest impacts by collecting critical geospatial data and developing predictive models. SAFARIS is developed and maintained by the NC State University, Center for Integrated Pest Management (CIPM) with support from PPQ PERAL. The SAFARIS team used a likelihood of establishment model for Japanese wax scale occurrence in the continental United States, that was developed by PPQ PERAL and NCSU CIPM, to support CAPS survey planning. The model predicts the suitability of an area for Japanese wax scale occurrence based on the likelihood of favorable conditions for the insect occurring using tools and data within SAFARIS. The detailed method used in this assessment is described here.

Surveys should begin in the fall and continue until mid-summer when adult females are most likely to be present.

Visually inspect host plants throughout the survey site for wax scales. Surveyors may want to conduct an initial visual inspection looking for stressed, dying plants or signs of wax scales (e.g., presence of honeydew, sooty mold, or noticeable bees or ants around a plant). 

After identifying host trees or bushes that are likely to be infested with scales or other hemipterans, search the canopy for scales. If no plants have visible signs of infestation, select random healthy plants evenly throughout the survey site for inspection. Consider surveying along straight-line transects, zig-zags, or W-patterns. 

Attempt to collect scales that match the appearance of C. japonicus, avoiding easily mistaken species where possible (See the CAPS pest datasheet for images). 

Differentiating between species of wax scales by eye is very difficult and final identification requires examination of microscopic morphological features. When in doubt, surveyors should collect any suspect specimen for identification.

Survey in citrus orchards, persimmon orchards, ornamental nurseries (e.g., holly), and urban environments where ornamental hosts are present (e.g., urban parks, botanical gardens). In sites with diverse vegetation, surveyors should focus on preferred hosts such as citrus, persimmon, holly, laurel, and ivy.

Scales are often present in protected, shaded, or sheltered parts of the plants, so surveyors should actively search the interior portions of host plants. Focus on the twigs, stems, and leaves of preferred hosts such as citrus, holly, and ivy. Japanese wax scale generally prefers the upper side of the leaves along the main veins but could occur anywhere on the plant.

Collect adult females; young adults are best for slide mount specimens, and it is ideal if they have recently molted. They should look nearly flat in comparison to the domed appearance of more mature individuals. 

Note: Nymphal stages should not be collected and may lead to incorrect identification.

We recommend removing an infested plant part (i.e., leaves and/or twigs) using garden shears or pruners. Because these methods can damage host plants, obtain permission from landowners or growers before attempting collection. Collecting individual insects is also possible, but more likely to damage the specimens. 

For individual leaves, small twigs, or individual insects, surveyors may place the entire sample in a vial with preservative (at least 70% ethanol is preferred) and appropriate labels. Larger samples can be bagged in brown wrapping paper, paper bags, and/or plastic bags and then stored in a plastic container or insulated food box to avoid crushing when transporting them from the field to the laboratory . If the plant parts are moist or wet, allow them to dry naturally to avoid mold growth.

The accurate identification of wax scales relies mainly on the morphology of slide-mounted adult females; wax cover keys should not be used.

The Scale insects ITP online resource provides fact sheets and interactive keys for slide-mounted adult females.

• Pellizzari and Camporese (1994) give a detailed morphological description of the adult female, including illustrations and descriptions. 

Regional and country keys are available as follows:

• Mediterranean Ceroplastes spp. (Pellizzari and Camporese, 1994)
• Ceroplastes species from the Palearctic region (Fetyko and Kozar, 2012)
• Ceroplastes species from Turkey (Kaydan and Kondo, 2008)
• Ceroplastes species from Greece (Papadopoulou et al., 2020)

For Ceroplastes species present in the United States, there are keys available for the states of Florida and California:

• Key to Ceroplastes species in Florida (Hodges, 2002)
• Key to Ceroplastes species present in California (Gill, 1988)

 The Gimpel et al. (1974) key for the Ceroplastes spp. in the United States is based on both slide-mounted specimens and on wax covers. We recommend slide-mounted specimens as the wax cover of some adult females changes in size, shape, and color with age.

Ceroplastes japonicus looks similar to other Ceroplastes species, as adult females all have a thick waxy covering that gives them a general dome appearance. Fourteen species of Ceroplastes are present in the United States, including several species that share hosts with C. japonicus. 

These species cannot be differentiated by eye; slide-mount specimens and a microscope are needed for identification. However, we are providing available visual guidance to assist during survey. 

• Ceroplastes floridensis most closely resembles C. japonicus. Ceroplastes floridensis is a cosmopolitan and highly polyphagous pest that uses similar hosts to C. japonicus, including citrus, holly, and laurel. It is present from Florida to New York and west to New Mexico, and it is common throughout the South.
• Ceroplastes ceriferus is another widespread scale in the Southeast that is similar to C. japonicus. Ceroplastes ceriferus prefers citrus, barberry, boxwood, Japanese euonymus, holly, ivy, scarlet firethorn, and quince. It can be differentiated from the other Ceroplastes species present in the South by the presence of an anteriorly projecting horn, which can be seen using a 20x hand lens.
• Ceroplastes rubens is a common wax scales in south Florida that difficult to differentiate from C. japonicus by eye. Ceroplastes rubens typically has a pink to reddish brown wax cover, while C. japonicus is typically fair in color (grayish to pinkish white) and C. rubens always has four white transverse bands of wax. This species is polyphagous and shares citrus, holly, ivy, and persimmon hosts with C. japonicus.
• Ceroplastes rusci is a common wax scales in south Florida that difficult to differentiate from C. japonicus by eye. Features that may help distinguish them in the field: Ceroplastes rusci has eight lateral plates, each with a depressed center separated from edges with indentations. This species is polyphagous and shares citrus, holly, ivy, and persimmon hosts with C. japonicus.

Five Ceroplastes spp. are present in California: C. cirripediformis, C. sinensis, C. cistudiformis, C. irregularis, and, more recently C. rusci (it was detected in fig orchards in San Diego Co., where it is reportedly under treatment).

• Ceroplastes cirripediformis and C. sinensis can be differentiated from C. japonicus by eye because they tend to have different colored wax covers with more defined dorsal and lateral plates. Ceroplastes cirripediformis is reddish brown to brown, while C. sinensis has the anterior half white and the rest light brown to pinkish brown (Gill, 1988).They have citrus as preferred hosts, and C. sinensis also has holly in common with C. japonicus. 
• Ceroplastes cistudiformis and C. irregularis generally are not pests and are unlikely to be encountered during visual surveys because C. cistudiformis only shares Citrus as a common host with C. japonicus and C. irregularis does not share any preferred hosts with C. japonicus.

See the Pest Datasheet for images of similar species.