A. trachoides is a polyphagous species with a preference for Solanaceae and Convolvulaceae. Solanaceous hosts include major cultivated species such as Capsicum spp., Solanum lycopersicum (tomato), S. melongena (aubergine),Nicotiana tabacum (tobacco), ornamentals (Cestrum, S. pseudocapsicum, S. seaforthianum) and wild plants/weeds (Datura stramonium, S. nigrum). The pest seems to be attacking mainly Capsicum spp., and to a lesser extent S. melongena and S. lycopersicum. The importance of host plants belonging to other families is not clear, but A. trachoides has been reported on cultivated plants such as, Annona spp., Citrus limon (lemon), Colocasiaesculenta (taro), Ipomoea batatas (sweet potato),Persea americana (avocado), Psidium guajava(guava), Theobroma cacao (cocoa), and Rosa.
The scale seems to be most destructive when plants are stressed from lack of water or hot direct sun. This is especially evident when the Crotons have been recently planted.
The insect infestation can be difficult to spot at first, blackened branches and defoliation are usually the first signs of trouble. When the leaves start dropping, the outbreak is already quite severe.
Once the insect has become established it quickly spreads to other plants in the area, and will kill most Crotons if left untreated.
Scale Treatment suggestions are available from the UF IFAS Extension website, or contact your garden pest control professional.
This video lists 70 species of plants which are affected by Croton Scale.