(Morgan, 1889)
Diagnosis
In life, scale cover of adult female nearly circular, flat, 1.5-2.0 mm diameter, greyish or reddish-brown, often with a coppery tinge; exuviae central, yellow or white CHRDIL4.jpg . Male scale cover similar to that of the female but elongate oval with subterminal exuviae CHRDIL3.jpg and CHRDIL.jpg . Body of living female yellow (Gill, 1997).
Body of slide-mounted adult female membranous, pyriform (never reniform); with front of head rounded; prepygidial segments each with fewer than five submarginal ducts on each side CHRDIS.jpg . Pygidium broad, subtended by an angle greater than 90°, with three pairs of rounded lobes; perivulvar pores present; paraphyses present only between third lobes, each paraphysis longer than a median lobe; second poriferous furrow (between segments VI and VII) on each side containing up to 10 macroducts in a single row CHRDIP.jpg .
Host range
Chrysomphalus dictyospermi is a highly polyphagous species; Borchsenius, 1966, recorded it from hosts belonging to 73 plant families, but its host range is probably wider than this. Favoured hosts are palms, Dracaena and Citrus species. Hosts include species of: Acacia, Acer, Agave, Albizia, Allamanda, Aloe, Alpinia, Anacardium, Annona spp., Anthurium, Aralia, Araucaria, Arbutus, Areca spp., Artocarpus altilis, Asparagus, Aspidosperma, Barringtonia, Bauhinia, Berberis, Buddleja, Buxus, Cactaceae, Calamus, Calathea, Calophyllum, Camellia, Canna, Carica papaya, Carissa, Carya, Casuarina, Ceratonia, Cinnamomum, Citrus spp., Coccoloba, Cocos spp., Codiaeum, Colocasia, Cordyline, Cotoneaster, Crataegus, Croton, Cupressus, Cycas spp., Cymbidium, Cyperus, Cypripedium, Dendrobium, Dianella, Dictyosperma, Diospyros, Dracaena, Elaeagnus, Elaeis guineensis, Epidendrum, Epipremnum, Eriobotrya, Erythrina, Eucalyptus, Eugenia, Euonymus, Euphorbia, Fatsia, Feijoa, Ficus spp., Fraxinus, Furcraea, Garcinia, Gleditsia, Grevillea, Hakea, Hedera, Heliconia, Hibiscus, Howea, Hyphaene, Ilex, Iris, Jasminum, Kigelia, Lagerstroemia, Latania, Laurus nobilis, Ligustrum spp., Livistona, Lonicera, Macadamia tetraphylla, Macaranga, Magnolia, Malpighia, Malus, Mammea, Mangifera indica, Manihot esculenta, Maranta, Maytenus, Melaleuca, Melia, Meryta, Metrosideros, Mimusops, Monstera, Morus, Muehlenbeckia, Musa, Myristica, Myrtus, Nerium, Odontoglossum, Olea europaea, Opuntia, Orchidaceae, Palmae, Pandanus, Passiflora, Pelargonium, Persea americana, Phoenix dactylifera, Phormium, Phytolacca, Pinus, Pistacea, Pittosporum, Platanus, Plumeria, Poncirus, Populus, Prunus, Psidium guajava, Punica, Pyrus, Quercus, Rhamnus, Rhus, Rosa, Roystonea, Ruscus, Ruta, Sabal, Salix, Schefflera, Schinus, Schuurmansia, Sida, Solanum melongena, Sonneratia, Sophora, Spermolepis, Spondias, Sterculia, Strelitzia, Swietenia, Syringa, Tamarindus, Taxus, Terminalia, Thuja, Thunbergia, Trachycarpus, Vanilla fragrans, Veitchia, Vitis, Xanthosoma,Yucca, Zamia and Zingiber.
Affected plant stages: vegetative growing, flowering, fruiting and post-harvest stages
Affected plant parts: especially on leaves CHRDDAMG.jpg ; sometimes on fruit and occasionally on branches CHRDIL2.jpg
Biology and ecology
Reproduction is sexual, and continuous in tropical conditions. In California, C. dictyospermi has 3 or 4 overlapping generations each year (Gill, 1997); in Egypt, only two (Salama, 1970). Crawlers are the primary dispersal stage and move to new areas of the plant or are dispersed by wind or animal contact. Mortality due to abiotic factors is high in this stage. Dispersal of sessile adults and eggs occurs through human transport of infested plant material.
Symptoms
Heavy infestations of C. dictyospermi can cover the tree. The toxic saliva injected while feeding causes leaf chlorosis CHRDDAMG.jpg , and drying and death of the branches.
Economic impact
This species is known mainly as a serious pest of Citrus (Zahradník, 1990). Danzig and Pellizzari, 1998, refer to C. dictyospermi as a dangerous pest in the Palaearctic region. Foldi, 2001, lists this species as an economically important pest in France. In the western Mediterranean region and Florida, C. dictyospermi is a serious pest of Citrus; it is a minor pest of Citrus, palms and young avocado trees in Mexico and South America (Chua and Wood, 1990; Gill, 1997). The species is of economic importance on several hosts in Brazil, and is regarded as a pest in Argentina, where it occurs on both cultivated and native plants; in Chile it is a primary pest on Citrus and is common on ornamental plants (Claps et al., 2001a). Chrysomphalus dictyospermi is a pest of olive in Italy, Spain and Turkey (Argyriou, 1990). The species has been reported as a significant pest of Citrus in a number of countries in the South Pacific Region (Williams and Watson, 1988).
Detection and inspection methods
Examine the leaves of the host-plants listed above closely, for circular, flat, greyish or reddish-brown scale covers (often with a coppery tinge), with yellow or white, central exuviae.
Phytosanitary risk and protection
Chrysomphalus dictyospermi is mentioned on quarantine lists (Burger and Ulenberg, 1990). It could become a serious pest of palms in greenhouses in the USA (Westcott, 1973).
Natural enemies
Parasitoids:
- Aphytis chilensis in Argentina
- Aphytis chrysomphali in Argentina, south-western USSR
- Aphytis proclia in Argentina
- Comperiella lemniscata, attacking: nymphs, adults, in China and India. Introduced: Australia, Israel
- Encarsia citrina in Argentina
- Encarsia ectophaga in Argentina
- Encarsia lounsburyi in South America
- Thysanus sp. in Uruguay
Distribution
See Chrysomphalus dictyospermi distribution.
Microscopic examination of slide-mounted adult females is required for authoritative identification to species. This species can be confused with Aonidiella aurantii in the field (Gill, 1997).
Comments
Chrysomphalus dictyospermi is probably native to southern China (Longo et al., 1995); it is widespread in tropical and subtropical regions, and occurs under glass in temperate areas (Davidson and Miller, 1990; Gill, 1997). In spite of the record published in Danzig and Pellizzari, 1998, C. dictyospermi has not been recorded in the United Kingdom in recent years and is regarded as absent (C.P. Malumphy, Central Science Laboratory, UK, pers. comm.).
Europe
Albania: present, no further details (Danzig and Pellizzari, 1998)
Bulgaria: present, no further details (CIE, 1969)
Former Czechoslovakia: present, no further details (Danzig and Pellizzari, 1998)
Former USSR: under glass, no further details (Danzig and Pellizzari, 1998)
Azerbaijan: present, no further details (CIE, 1969)
Caucasus: present, no further details (CIE, 1969)
Crimea: present, no further details (CIE, 1969)
Georgia, Republic of: present, no further details (CIE, 1969)
Transcaucasus: present, no further details (CIE, 1969)
Turkmenistan: present, no further details (CIE, 1969)
Former Yugoslavia: The Natural History Museum collection, London, UK
France: present, no further details (Foldi, 2001)
Corsica: present, no further details (CIE, 1969)
Germany: present, no further details (Danzig and Pellizzari, 1998)
Greece: present, no further details (Danzig and Pellizzari, 1998)
Crete: present, no further details (CIE, 1969)
Italy: present, no further details (Longo et al., 1995; Danzig and Pellizzari, 1998)
Sardinia: present, no further details (Longo et al., 1995)
Sicily: present, no further details (Longo et al., 1995)
Malta: present, no further details (Danzig and Pellizzari, 1998)
Portugal: present, no further details (Danzig and Pellizzari, 1998)
Azores: present, no further details (CIE, 1969)
Madeira: present, no further details (Danzig and Pellizzari, 1998)
Romania: present, no further details (Danzig and Pellizzari, 1998)
Spain: widespread (Amparo Blay Golcoechea, 1993)
Balearic Is: present, no further details (Amparo Blay Golcoechea, 1993)
Canary Is: present, no further details (Amparo Blay Golcoechea, 1993)
Asia
China
Fukien: present, no further details (CIE, 1969)
Hong Kong: present, no further details (CIE, 1969)
Hunan: present, no further details (CIE, 1969)
Hupeh: present, no further details (CIE, 1969)
Guangdong: present, no further details (CIE, 1969)
Shantung: present, no further details (CIE, 1969)
India
Assam: present, no further details (CIE, 1969)
Karnataka: The Natural History Museum collection, London, UK
Kerala: The Natural History Museum collection, London, UK
Sikkim: present, no further details (CIE, 1969)
Tamil Nadu: present, no further details (CIE, 1969)
West Bengal: present, no further details (CIE, 1969)
Indonesia
Irian Jaya: present (Williams and Watson, 1988)
Java: present, no further details (CIE, 1969)
Sumatra: present, no further details (CIE, 1969)
Iran: present, no further details (Seghatoleslami, 1977; Abivardi, 2001)
Iraq: present, no further details (Danzig and Pellizzari, 1998)
Israel: present, no further details (Danzig and Pellizzari, 1998)
Japan: present (Kawai, 1980)
Hokkaido: present, no further details (CIE, 1969)
Honshu: present, no further details (CIE, 1969)
Shikoku: present, no further details (CIE, 1969)
Korea: present, no further details (Danzig and Pellizzari, 1998)
Lebanon: present, no further details (CIE, 1969)
Malaysia
West Malaysia: present, no further details (CIE, 1969)
Sarawak: present, no further details (CIE, 1969)
Myanmar: present, no further details (CIE, 1969)
Philippines: present, no further details (CIE, 1969; Velasquez, 1971)
Ryukyu Is: present, no further details (CIE, 1969)
Sri Lanka: present, no further details (CIE, 1969)
Syria: present, no further details (Danzig and Pellizzari, 1998)
Taiwan: present, no further details (Wong et al., 1999)
Thailand: present, no further details (CIE, 1969)
Turkey: present, no further details (Danzig and Pellizzari, 1998)
Vietnam: present, no further details (CIE, 1969)
Africa
Algeria: present, no further details (Danzig and Pellizzari, 1998)
Angola: present, no further details (CIE, 1969)
Cameroon: present, no further details (CIE, 1969)
Cape Verde Is: The Natural History Museum collection, London, UK
Côte d'Ivoire: present, no further details (CIE, 1969)
Congo Democratic Republic: present, no further details (CIE, 1969)
Egypt: present, no further details (Salama, 1970)
Ethiopia: present, no further details (CIE, 1969)
Guinea: present, no further details (CIE, 1969)
Kenya: present, no further details (CIE, 1969)
Libya: present, no further details (CIE, 1969)
Madagascar: present, no further details (CIE, 1969)
Mali: present, no further details (CIE, 1969)
Mauritius: present, no further details (Williams and Williams, 1988)
Morocco: present, no further details (Danzig and Pellizzari, 1998)
Niger: present, no further details (CIE, 1969)
Nigeria: present, no further details (CIE, 1969)
Réunion: present, no further details (Williams and Williams, 1988)
Rodrigues: present, no further details (Williams and Williams, 1988)
Senegal: present, no further details (CIE, 1969)
Seychelles: present, no further details (CIE, 1969)
Sierra Leone: present, no further details (CIE, 1969)
Somalia: present, no further details (CIE, 1969)
South Africa: present, no further details (CIE, 1969)
Sudan: present, no further details (CIE, 1969)
Tanzania: present, no further details (CIE, 1969)
Zanzibar: present, no further details (CIE, 1969)
Togo: present, no further details (CIE, 1969)
Tunisia: present, no further details (Danzig and Pellizzari, 1998)
Uganda: present, no further details (CIE, 1969)
Zambia: present, no further details (CIE, 1969)
Zimbabwe: present, no further details (CIE, 1969)
Western Hemisphere
Argentina
Buenos Aires: present, no further details (Claps et al., 2001a)
Catamarca: present, no further details (Claps et al., 2001a)
Córdoba: present, no further details (Claps et al., 2001a)
Corrientes: present, no further details (CIE, 1969)
Entre Rios: present, no further details (CIE, 1969)
Jujuy: present, no further details (Claps et al., 2001a)
Mendoza: present, no further details (CIE, 1969)
Misiones: present, no further details (CIE, 1969)
Paraná Delta: present, no further details (CIE, 1969)
Salta: present, no further details (CIE, 1969)
San Juan: present, no further details (Claps et al., 2001a)
San Luís: present, no further details (Claps et al., 2001a)
Tucumán: present, no further details (Claps and Terán, 2001)
Bahamas: present, no further details (CIE, 1969)
Barbados: present, no further details (Bennett and Alam, 1985)
Bermuda: present (Hodgson and Hilburn, 1991)
Bolivia: present, no further details (Squire, 1972a)
Brazil
Bahia: present, no further details (Claps et al., 2001a)
Guanabara: present, no further details (Silva et al., 1968)
Paraná: present, no further details (Silva et al., 1968; Claps et al., 2001a)
Rio de Janeiro: present, no further details (Claps et al., 2001a)
Rio Grande do Sul: present, no further details (Claps et al., 2001a)
Sao Paulo: present, no further details (Claps et al., 2001a)
Chile
Antofagasta: present, no further details (Claps et al., 2001a)
Atacama: present, no further details (Claps et al., 2001a)
Coquimbo: present, no further details (Claps et al., 2001a)
Easter Island: present, no further details (Charlín, 1973; Claps et al., 2001a)
Maule: present, no further details (Claps et al., 2001a)
O'Higgins: present, no further details (Claps et al., 2001a)
Santiago: present, no further details (Claps et al., 2001a)
Tarapacá: present, no further details (Claps et al., 2001a)
Valparaiso: present, no further details (Claps et al., 2001a)
Colombia: present, no further details (CIE, 1969; Kondo, 2001)
Costa Rica: present, no further details (CIE, 1969)
Cuba: present, no further details (CIE, 1969)
Dominican Republic: present, no further details (CIE, 1969)
Ecuador: The Natural History Museum collection, London, UK
Grenada: present, no further details (CIE, 1969)
Guatemala: present, no further details (CIE, 1969)
Guyana: present, no further details (Beardsley, 1966)
Honduras: present, no further details (CIE, 1969)
Jamaica: present, no further details (CIE, 1969)
Mexico: widespread (Miller, 1996)
Nicaragua: present, no further details (CIE, 1969)
Panama: present, no further details (CIE, 1969)
Paraguay: present, no further details (CIE, 1969)
Peru: present, no further details (CIE, 1969)
Puerto Rico: present, no further details (CIE, 1969)
Suriname: present, no further details (CIE, 1969)
Trinidad: present, no further details (CIE, 1969)
Uruguay: present, no further details (CIE, 1969)
USA
Alabama: present, no further details (Nakahara, 1982)
Arizona: present, no further details (Nakahara, 1982)
California: present only under glass or indoors (Gill, 1997)
Colorado: present, no further details (Nakahara, 1982)
Connecticut: present, no further details (Nakahara, 1982)
District of Colombia: present, no further details (Nakahara, 1982)
Florida: present, no further details (Nakahara, 1982)
Georgia: present, no further details (Nakahara, 1982)
Hawaii: present on Oahu, Hawaii, Maui and Kauai (Heu, 2002)
Illinois: present, no further details (Nakahara, 1982)
Indiana: present, no further details (Nakahara, 1982)
Kansas: present, no further details (Nakahara, 1982)
Louisiana: present, no further details (Nakahara, 1982)
Massachusetts: present, no further details (Nakahara, 1982)
Maryland: present, no further details (Nakahara, 1982)
Michigan: present, no further details (Nakahara, 1982)
Minnesota: present, no further details (Nakahara, 1982)
Missouri: present, no further details (Nakahara, 1982)
Mississippi: present, no further details (Nakahara, 1982)
North Carolina: present, no further details (Nakahara, 1982)
New Hampshire: present, no further details (Nakahara, 1982)
New Jersey: present, no further details (Nakahara, 1982)
New Mexico: present, no further details (Nakahara, 1982)
New York: present, no further details (Nakahara, 1982)
Ohio: present, no further details (Nakahara, 1982)
Pennsylvania: present, no further details (Nakahara, 1982)
Rhode Island: present, no further details (Nakahara, 1982)
South Carolina: present, no further details (CIE, 1969)
Tennessee: present, no further details (Nakahara, 1982)
Texas: present, no further details (Nakahara, 1982)
Utah: present, no further details (Nakahara, 1982)
Virginia: present, no further details (Nakahara, 1982)
West Virginia: present, no further details (Nakahara, 1982)
Venezuela: present, no further details (CIE, 1969)
Oceania
Australia: present, no further details (CSIRO, 2001)
Queensland: present, no further details (CIE, 1969)
Bonin Is: present (Beardsley, 1966)
Caroline Is: present, no further details (CIE, 1969)
Cook Is: present (Williams and Watson, 1988)
Fiji: present (Williams and Watson, 1988)
Johnston I.: present, no further details (CIE, 1969)
Kiribati: present (Williams and Watson, 1988)
Marshall Is: present (Beardsley, 1966)
New Caledonia: present, no further details (Cohic, 1958)
Niue: present (Williams and Watson, 1988)
Norfolk I.: The Natural History Museum collection, London, UK
Palau: present (Beardsley, 1966)
Papua New Guinea: present (Williams and Watson, 1988)
Solomon Is: present (Williams and Watson, 1988)
South Mariana Is: present (Beardsley, 1966)
Tahiti: present (Williams and Watson, 1988)
Tonga: present (Williams and Watson, 1988)
Truk Is: present (Beardsley, 1966)
Tuvalu: present (Williams and Watson, 1988)
Western Samoa: present (Williams and Watson, 1988)