This rapid assessment shows: 

Risk of entry – very unlikely

The main route of entry is likely to be on growing ornamental plants from countries where the scale has been reported. However, despite the large volume of imported plants the incidence of C. rubens is very low. Detection of early instars is difficult, particularly when present at low density. The scale may only be observed when mature specimens are present or numbers have built up to such a density that they are already causing damage. 

Risk of establishment – in protected ornamentals is moderately likely

 It is very unlikely to naturalise and overwinter outdoors in Britain but could establish on indoor plantings, at least as transient populations. Rate of spread – very slow (natural spread) to moderate pace (in trade) Spread is most likely to be with infested plants in trade. Economic impact – very small It is an important economic pest of many tropical and subtropical crops, and citrus, none of which are grown as commercial crops in the UK. It may have a small impact on the aesthetic quality and market value of indoor ornamental plants but there is little data available to quantify the economic implications.

Endangered area – protected ornamentals 

Risk management

In the absence of phytosanitary measures the scale is likely to continue to enter the UK. It may be controlled using the same products used for other soft scales already present in the UK.