- Worldwide distribution. On many woody plants, trees, ornamentals and weeds. Important, potentially devastating on citrus.
- Damage: (i) sucks sap, leaves wilt, stems dry, and shoots dieback, (ii) honeydew drips onto foliage which is blackened by sooty moulds.
- Adult (females) up to 7 mm long, covered in yellow or white wax, with orange-red, yellow, brown body. They are hermaphrodites; fertilised eggs kept in fluted egg sac. Males winged, and rare.
- Spread by 'crawlers' (nymphs) walking, or carried by wind, vehicles, animals, birds, on clothes, and the trade in plants.
- Natural enemies: predators, e.g., ladybird beetle, Rodolia cardinalis, and fly parasitoid (Cryptochaetum).
- Cultural control: nursery stock free from scale; if present, prune and spray (see below); in field, provide adequate nutrition.
- Chemical control: spot-spray infestations with soap solution, horticultural or white oils (see Fact Sheet no. 56); avoid malathion and synthetic pyrethroids - they will kill natural enemies. Use pyrethroids against ants.
Pacific Pests, Pathogens, Weeds & Pesticides
Citrus fluted scale (343)
Citrus fluted scale, cottony cushion scale,
AUTHOR Grahame Jackson
1Information from Swaine G (1971) Agricultural Zoology in Fiji. Her Majesty's Stationery Office. London; and CABI (2016) Icerya purchasi (cottony cushion scale). Crop Protection Compendium. (https://www.cabi.org/cpc/datasheet/28432); and Icerya purchasi. Wikipedia. (https://en.wikipedia.org/wiki/Icerya_purchasi); and Icerya purchasi Maskell. Featured Creatures, Entomology & Nematology. UF/IFAS, University of Florida. (http://entnemdept.ufl.edu/creatures/fruit/cottony_cushion_scale.htm); and from Weeks JA (2012) Citrus Pests Cottony cushion scale Icerya purchasi (Hemiptera: Margarodidae). USDA, University of Florida. (https://idtools.org/id/citrus/pests/factsheet.php?name=Cottony+cushion+scale); Photos 1&5 Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services, Bugwood.org. Photo 2 Lesley Ingram, Bugwood.org. Photo 3 Lorraine Graney, Bartlett Tree Experts, Bugwood.org. Photo 4 Sonya Broughton, Department of Agriculture & Food Western Australia, Bugwood.org.
Produced with support from the Australian Centre for International Agricultural Research under project PC/2010/090: Strengthening integrated crop management research in the Pacific Islands in support of sustainable intensification of high-value crop production, implemented by the University of Queensland and the Secretariat of the Pacific Community.