Saissetia coffeae Walker
Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Coccoidea, Coccidae.
Common name: Hemispherical scale.
Geographical distribution: This scale occur in the tropics, sub-tropical regions, and in greenhouses in temperate regions. CABI Distribution Maps of Pests, Series A, #318, 1973.
Host plants: Polyphagous.
Morphology: Body of adult female 2-3 mm long, dorsum hemispherical, hard and shiny, red-brown. Body of immature female flat, yellow-brown, with three dorsal ridges resembling the letter H, which disappear at maturity.
Life history: At 30°C the pest completes a generation in about 8 weeks, and lays almost 500 eggs/female, reproducing by parthenogenesis. In the Middle East it raises 2-3 annual generations.
Economic importance: Saissetia coffeae is a pest of coffee, tea, citrus, olive and gauva as well as ornamentals, especially Sago palm, Cycas revolute Thunberg, and various ferns. Its main damage is due to the excretion of copious amounts of honeydew that are colonized by black sootymold, contaminating all lower surfaces. The honeydew also attracts ants that protect the pest from its natural enemies. Severe, prolonged infestations reduce plant vigour and can cause its death.
Although usually controlled by its natural enemies, outbreaks may occur after applications of nonselective pesticides that kill the enemies.
Monitoring: Abundant honeydew on susceptible plants indicates the presence of the pest, which is easily seen as shiny, round red-brown spots on leaves and twigs.
Horticultural methods: Careful inspection of plant material intended for greenhouse cultivation and the removal of infested plant parts.
Chemical control: Because natural enemies often control this pest, there is usually no need for chemical treatments. When sprays are applied, they should be aimed at the early nymphal stages, because the eggs are protected and shielded by the hard, waxy cover of the mother. White oils applied against the scale infesting Sago palms reduced its numbers.
Biological control: This scale is usually controlled by its indigenous and introduced parasitoids, especially Encyrtidae and Pteromalidae, which can destroy 50-80% of the pest populations. However, the eggs of the encyrtids Encyrtus infelix (Embleton) and Metaphycus swirskii Annecke and Mynhardt may be encapsulated by the pest, reducing the efficacy of these enemies.
Abd Rabou, S., Ali, N. and El-Fatih, M.M. 2009. Life table of the hemispherical scale, Saissetia coffeae (Walker) (Hemiptera: Coccidea). Egyptian Academy Journal of Biological Sciences, A. 2: 165-170.
Abd-Rabou, S. 2005. Importation, colonization and establishment of Coccophagus cowperi Gir. (Hymenoptera: Aphelinidae) on Saissetia coffeae (Walk.)(Homoptera: Coccidae) in Egypt. Journal of Pest Science 78: 77-81.
Blumberg, D. 1988. Encapsulation of eggs of the encyrtid wasp Metaphycus swirskii, by the hemispherical scale, Saissetia coffeae: Effect of host age and rearing temperature. Entomologia Experimentalis et Applicata 47: 95-99.
Blumberg, D. and Goldenberg, S. 1992. Encapsulation of eggs of two species of Encyrtus (Hymenoptera: Encyrtidae) by soft scales (Homoptera: Coccidae) in six parasitoid-host interactions. Israel Journal of Entomology 25-26: 57-65.
Mesbah, H.A., Nagda, A.S., Mourad, A.K., Abdel-Razak, I.S. and Samar, E.A. 2010. Efficacy of five volatile oils and their mixtures against the soft scale insect, Saissetia coffeae (Walker) (Hemiptera: Coccidae) infesting the Sago palm, Cycas revolute in Alexandria, Egypt. Communications in Agricultural and Applied Biological Sciences 75: 379-89.
Morsi, G. A. 2010. Seasonal abundance of the hemispherical soft scale insect, Saissetia coffeae (Walker) (Homoptera: Coccidae) and its parasitods on olive in Middle Egypt. Egyptian Journal of Biological Pest Control 20: 139-142 ABSTRACT
Rosen, D., Harpaz, I. and Samish, M.1971. Two species of Saissetia (Homoptera: Coccoidea: Coccidae) injurious to olive in Israel and their natural enemies. Israel Journal of Entomology 6: 35-53.