Sphaerolecanium prunastri (Fonscolombe)
Common name: Globose scale.
Geographical distribution: A Palearctic species, present in Turkey, Lebanon and Israel.
Host plants: Rosaceous perennials, especially stone fruit trees like Prunus..
Morphology: Body of female almost round, the shield dark brown or black, covered by dark-brown wax which imparts the insect (especially the post-reproductive females) a strongly convex aspect. Dorsally the body bears long medial setae, but it totally lacks tubular ducts. Scale of male (sometimes called “test”) elongated, transparently white.
Life history: The pest raises one annual generation, overwintering as 2nd-stage nymphs. Oviposition takes place during April-May. The crawlers prefer to settle on twigs, seldom occur on trunks, never on leaves, young twigs or branches. Reproduction is arrhenotokous, each female producing up to 3,000 eggs. The insects may be associated with protecting ants.
Economic importance: In Turkey this is a major pest of Prunus spp. Its damage is mostly due to secreting much honeydew, colonized by sootymold fungi, covering fruits and leaves by a thick black mass. Trees may weaken, shed their leaves and even die.
Biological control: In Turkey the pest is heavily attacked (up to 70% parasitism) by several endoparasitoids, including Discodes coccophagus Ratzeburg (Encyrtidae). Other control measurements are usually unecessary unless the natural enemies are killed by pesticides.
Ben-Dov, Y. 1968. Occurrence of Sphaerolecanium prunastri (Fonscolombe) in Israel and description of its hitherto unknown third larval instar. Annales des Epiphyties 18: 615-621.
Japoshvili, G., Ay, R., Karaca, I., Gabroshvili, N., Barjadze, S. and Chaladze, G. 2008. Studies on the parasitoid complex attacking the globose scale Sphaerolecanium prunastri (Fonscolombe) (Hemiptera: Coccoidea) on Prunus species in Turkey. Journal of the Kansas Entomological Society 81: 339-344
Karaca, I., Japoshvili, G. and Demirozer, O. 2003. The chalcid parasitoid complex (Hymenoptera : Chalcidoidea) associated with the globose scale (Sphaerolecanium prunastri Fonscolombe) (Hemiptera: Coccoidea) in Isparta Province, Turkey and some east European countries. Zeitschrift fur Pflanzenkranheiten und Pflanzenschutz 110: 505-511.
Kosztarab, M. and Kozar, F. 1988. Scale Insects of Central Europe. Junk, Dordrecht, The Netherlands.