Cottony cushion scale
Icerya purchasi
111 host plants
Last updated
Cottony cushion scale produces distinctive pink, fluffy egg sacs on rhododendron and other plants, creating a very visible cottony appearance on stems and branches. You will see the white to pink ovisacs particularly in spring and early summer. Scale insects feed on plant sap, weakening affected branches. Heavy infestations cause branch dieback and yellowing of foliage, though damage is typically less severe than with cottony maple scale on other hosts.
Conserve vedalia beetles and parasitoid wasps for biological control; avoid broad-spectrum insecticides. Prune lightly infested twigs by hand. Spray insecticidal soap at crawler emergence in early summer. Maintain plant health through proper watering and pruning.
Quick Reference
Order
Hemiptera
Type
scale
Host Plants
111
Damage Severity
growth-reducing
Cultural Controls
- Control ants with trunk banding (Tanglefoot) or ant baits to improve biological control - ants protect scales for honeydew
- Conserve natural enemies by avoiding persistent insecticides and controlling dust
- Inspect for vedalia beetle eggs/larvae on scale egg sacs and Cryptochaetum emergence holes before treating - if present, insecticides not necessary
- Prune heavily infested branches
- Wrap trunk with duct tape or fabric before applying sticky bands to protect sensitive bark (especially citrus)
Host Plants (111)
Nandina domestica Heavenly Bamboo Sacred Bamboo, Nandina Rhododendron 'Alice' Alice Rhododendron Rhododendron 'Anah Kruschke' Anah Kruschke Rhododendron Rhododendron 'Anna Rose Whitney' Anna Rose Whitney Rhododendron Rhododendron 'Argosy' Argosy Rhododendron Rhododendron 'Bruce Briggs' Bruce Briggs Rhododendron Rhododendron 'Capistrano' Capistrano Rhododendron Rhododendron 'Carmen' Carmen Rhododendron Rhododendron 'Cheer' Cheer Rhododendron Rhododendron 'Cilpinense' Cilpinense Rhododendron Rhododendron 'Crest' Crest Rhododendron Rhododendron 'Cunningham's White' Cunningham's White Rhododendron Rhododendron 'Cynthia' Cynthia Rhododendron Rhododendron 'Dora Amateis' Dora Amateis Rhododendron Rhododendron 'Dreamland' Dreamland Rhododendron Rhododendron 'Elizabeth' Elizabeth Rhododendron Rhododendron 'Fantastica' Fantastica Rhododendron Rhododendron 'Gibraltar' Gibraltar Azalea Rhododendron 'Girard's Fuchsia' Girard's Fuchsia Azalea Rhododendron 'Glacier' Glacier Azalea Rhododendron 'Goldflimmer' Goldflimmer Rhododendron Rhododendron 'Gomer Waterer' Gomer Waterer Rhododendron Rhododendron 'Hallelujah' Hallelujah Rhododendron Rhododendron 'Hino-Crimson' Hino-Crimson Azalea Rhododendron 'Horizon Monarch' Horizon Monarch Rhododendron Rhododendron 'Hotei' Hotei Rhododendron Rhododendron 'Jock' Jock Rhododendron Rhododendron 'Klondyke' Klondyke Azalea Rhododendron 'Lee's Dark Purple' Lee's Dark Purple Rhododendron Rhododendron 'Lord Roberts' Lord Roberts Rhododendron Rhododendron 'Mandarin Lights' Mandarin Lights Azalea Rhododendron 'Moonstone' Moonstone Rhododendron Rhododendron 'Mother's Day' Mother's Day Azalea Rhododendron 'Nancy Evans' Nancy Evans Rhododendron Rhododendron 'Nova Zembla' Nova Zembla Rhododendron Rhododendron 'P.J.M.' P.J.M. Rhododendron Rhododendron 'Peekaboo' Peekaboo Rhododendron Rhododendron 'Percy Wiseman' Percy Wiseman Rhododendron Rhododendron 'Pohjola's Daughter' Pohjola's Daughter Rhododendron Rhododendron 'Purple Gem' Purple Gem Rhododendron Rhododendron 'Ramapo' Ramapo Rhododendron Rhododendron 'Rosamundi' Rosamundi Rhododendron Rhododendron 'Roseum Elegans' Roseum Elegans Rhododendron Rhododendron 'Sappho' Sappho Rhododendron Rhododendron 'Solidarity' Solidarity Rhododendron Rhododendron 'Stewartstonian' Stewartstonian Azalea Rhododendron 'Taurus' Taurus Rhododendron Rhododendron 'The Honourable Jean Marie de Montague' Jean Marie Rhododendron Rhododendron 'Trilby' Trilby Rhododendron Rhododendron 'Unique' Unique Rhododendron Rhododendron 'Vulcan' Vulcan Rhododendron Rhododendron 'Winsome' Winsome Rhododendron Rhododendron 'Yaku Prince' Yaku Prince Rhododendron Rhododendron 'Yaku Princess' Yaku Princess Rhododendron Rhododendron alabamense Alabama Azalea Rhododendron arboreum subsp. cinnamomeum Cinnamon Rhododendron Rhododendron augustinii Augustine Rhododendron Rhododendron auriculatum No common name (R. auriculatum) Rhododendron bibiani Bibiani Rhododendron Rhododendron bureavii Bureau Rhododendron Rhododendron campylocarpum subsp. coloxanthum Coloxanthum Rhododendron Rhododendron catawbiense Catawba Rhododendron Rhododendron cinnabarinum Cinnabar Rhododendron Rhododendron concinnum Concinnum Rhododendron Rhododendron daphnoides Daphnoides Rhododendron Rhododendron dauricum Dauricum Rhododendron Rhododendron davidsonianum Davidsonianum Rhododendron Rhododendron falconeri subsp. falconeri Falconer Rhododendron Rhododendron formosum var. formosum Formosum Rhododendron Rhododendron forrestii subsp. forrestii Forrest Rhododendron Rhododendron fortunei subsp. discolor Fortune Discolor, Discolor Rhododendron Rhododendron groenlandicum Labrador-tea, Labrador Tea Rhododendron haematodes subsp. haematodes Haematodes Rhododendron Rhododendron hanceanum Hanceanum Rhododendron Rhododendron hippophaeoides var. hippophaeoides Hippophaeoides Rhododendron Rhododendron hodgsonii Hodgson Rhododendron Rhododendron irroratum Irroratum Rhododendron Rhododendron johnstoneanum Rhododendron, johnstoneanum Rhododendron keiskei Keiskei Rhododendron, Keisuki Rhododendron Rhododendron kiusianum Kiusianum Azalea, Kyushu Azalea Rhododendron lacteum Lacteum Rhododendron Rhododendron luteiflorum Luteiflorum Rhododendron Rhododendron lutescens Lutescens Rhododendron Rhododendron luteum Pontic or Pontica Azalea Rhododendron macabeanum Macabeanum Rhododendron Rhododendron macrophyllum Pacific Rhododendron Rhododendron mucronulatum Rhododendron, mucronulatum Rhododendron myrtifolium Myrtifolium Rhododendron Rhododendron niveum Niveum Rhododendron Rhododendron occidentale Western Azalea Rhododendron orbiculare subsp. orbiculare Obiculare Rhododendron Rhododendron oreotrephes Oreotrephes Rhododendron Rhododendron pachytrichum Pachytrichum Rhododendron Rhododendron ponticum Rhododendron, ponticum Rhododendron prinophyllum Roseshell Azalea, Pinkshell Azalea Rhododendron prunifolium Plumleaf Azalea Rhododendron quinquefolium Quinquefolium Azalea Rhododendron racemosum Racemosum Rhododendron Rhododendron roxieanum var. oreonasters No common name Rhododendron rubiginosum Rubiginosum Rhododendron Rhododendron schlippenbachii Royal Azalea Rhododendron serpyllifolium Wild Thyme, Azalea Rhododendron serpyllifolium var. albifolrum White Wild Thyme, Azalea Rhododendron sinofalconeri Sinofalconer Rhododendron Rhododendron sinogrande Sinogrande Rhododendron Rhododendron smirnowii Smirnow Rhododendron Rhododendron stenopetalum Rhododendron, stenopetalum Rhododendron thomsonii subsp. thomsonii Thomson Rhododendron Rhododendron wardii Ward Rhododendron Rhododendron wiltonii Wilton Rhododendron Rhododendron yakushimanum Yak Rhododendron
Data Maturity Baseline Extension data. Expert review underway.