Coccus viridis

(Green, 1889)

green scale, green coffee scale, coffee green scale

Coccus viridis is a (: ) and major agricultural pest with a wide tropical and subtropical distribution. It reproduces parthenogenetically via , with females producing 50-600 that hatch within minutes to hours beneath the mother's body. The completes its in 47-51 days at 25°C, with three nymphal before adulthood; first-instar actively disperse as '' while older instars and become . It is , feeding on phloem sap of over 200 in 72 , with primary to coffee, guava, and cacao .

Coccus viridis by (c) aubrey_moore, some rights reserved (CC BY), uploaded by aubrey_moore. Used under a CC-BY license.

Coccus viridis by Jeffrey W. Lotz. Used under a CC BY 3.0 license.

Coccus viridis (03) by Lyn Cook. Used under a CC BY 4.0 license.

Pronunciation

How to pronounce Coccus viridis: /ˈkɒk.kəs vɪˈraɪ.dɪs/

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Identification

can be distinguished from other green-colored by the combination of pale green coloration with visible black internal markings through the body wall, the flattish elongated oval dome shape, and the distinctive groove at the end. The nymphal stages show progressive convexity with each . Parthenogenetic and absence of males in most may aid identification in laboratory settings.

Images

Appearance

females are pale green with distinctive black internal markings visible through the body wall. The body is flattish, elongated oval, and dome-shaped, approximately 3 mm in width. The end is rounded, while the end has a distinctive groove. Adults retain legs and but are mostly sedentary. are flattish oval, yellowish-green, with six short legs. Each successive is larger and more convex, with three molts before adulthood.

Habitat

Tropical and subtropical regions worldwide. In the European Union, restricted to Azores and Madeira Islands. Potential for establishment in southern and central EU countries outdoors, with greenhouse and indoor establishment possible in areas where outdoor survival is uncertain.

Distribution

Widespread in tropical and subtropical Americas, Africa, Asia, and Oceania. Specific records include: Asia (Bangladesh, Burma, Cambodia, India, Indonesia, Laos, Malaysia, Pakistan, Philippines, Sri Lanka, Taiwan, Thailand, Vietnam); Africa (Angola, Cameroon, Cape Verde, Ethiopia, Ghana, Guinea, Ivory Coast, Kenya, Madagascar, Madeira, Mali, Mauritius, Niger, Nigeria, Príncipe, Réunion, São Tomé, Senegal, Seychelles, Sierra Leone, South Africa, Tanzania, Togo, Uganda, Zambia, Zaire); Australasia and Pacific Islands (Australia, Caroline Islands, Fiji, Gilbert and Ellice Islands, Hawaii, Marianas Islands, New Caledonia, Papua New Guinea, Samoa, Society Islands, Tonga, Irian Jaya); North America (Mexico, USA); Central America and West Indies (El Salvador, Guatemala, Nicaragua, Panama, West Indies); South America (Bolivia, Brazil, Colombia, Guyana, Peru, Suriname, Venezuela).

Seasonality

Multiple overlapping annually; 3-4 generations per year in Queensland, 4-5 in Taiwan, with generation time of 50-70 days in South Florida summer. Seasonal peaks vary by region.

Diet

Phloem-feeding on sap. : documented from over 200 in 72 plant . Primary include Coffea arabica (coffee), Psidium guajava (guava), and Theobroma cacao (cacao). Other significant hosts: Anacardium occidentale (cashew), Manihot esculenta (cassava), Citrus spp., Cocos nucifera (coconut), Litchi chinensis (lychee), Eriobotrya japonica (loquat), Mangifera indica (mango), Carica papaya (papaya), Pyrus communis (pear), Cajanus cajan (pigeon pea), Ananas comosus (pineapple), Manilkara zapota (sapodilla), Camellia sinensis (tea). Also recorded on ornamentals including Camellia, Ficus, Gardenia, Ixora, Jasminum polyanthum, and Salacia crassifolia.

Host Associations

Coffea arabica - primary Major economic impact; nursery seedlings and mature trees
Psidium guajava - primary Major economic impact
Theobroma cacao - primary Major economic impact
Citrus sinensis - Recorded in Brazil study
Salacia crassifolia - New record from Brazilian Cerrado, 2022

Life Cycle

, parthenogenetic via (males extremely rare). Females lay 50-600 whitish oval beneath their body for protection. Eggs hatch within minutes to hours. Three nymphal precede adulthood. First instar ('') actively disperses to feeding sites on leaf undersides (midrib, ), , stems, young , and fruits. Second and third instars and become , remaining at selected feeding locations. Development times at 25°C: first instar 10-15 days, second instar 8-12 days, third instar 8-12 days; total egg-to-first- 47-51 days.

Behavior

First- actively search and select feeding locations, showing positive and capacity. Older nymphs and remain motionless at feeding sites, forming often aligned along leaf midribs and . Adults and nymphs excrete , which attracts , , and ; this mutualistic relationship with ants (particularly Pheidole in Hawaii) involves ant defense against in exchange for honeydew access. Ant presence significantly increases reproductive success and reduces mortality from .

Ecological Role

Agricultural pest causing direct damage through phloem feeding and indirect damage via and development. Heavy cause leaf yellowing, premature leaf drop, loss of vigor, and reduced yield. Sooty mold growth on honeydew reduces photosynthetic area and marketability of fruits. Serves as for (notably Azya luteipes) and other . Subject to natural regulation by including Cephalosporium lecanii (= lecanii) and Lecanicillium lecanii.

Human Relevance

Major economic pest of coffee production worldwide, with historical regional failures attributed to this . Significant pest of guava, cacao, citrus, and many other tropical crops. Entry to new regions include plants for planting, fruits, vegetables, and cut flowers. Management approaches include of planting material, chemical control (carbaryl, malathion, methomyl, Volck ), using , and colony suppression to disrupt mutualistic protection. Listed as potential for EU.

Similar Taxa

Nipaecoccus viridisDifferent ( vs. ); with waxy covering rather than green ; produces ; field identification possible through KOH/NaOH color test (green ) unique to this
Coccus hesperidumCongeneric ; coloration rather than green; lacks distinctive black internal markings visible through body wall
Saissetia coffeaeBlack ; dark to black coloration; hemispherical shape rather than flattish oval dome

More Details

Climate Relationships

Field studies in Mexico and India demonstrate correlations between C. viridis and climatic factors. Pest show positive correlation with maximum and temperatures, while fungal by Cephalosporium lecanii shows negative correlation with temperature and positive correlation with humidity and rainfall.

Spatial Distribution Pattern

Geostatistical analysis in Mexican coffee plantations reveals aggregated spatial distribution with high spatial association between C. viridis and fumagina (Capnodium spp. ), with correlation coefficient r = 0.70, indicating clustered foci suitable for targeted management.

Taxonomic History

Originally described as Lecanium viride Green, 1889; transferred to Coccus. The specific epithet 'viridis' refers to the green coloration of females.