Coccoidea

Scale insects (which include mealybugs) are distinguished from other groups of Sternorrhyncha by possession of a single claw at the apex of each tarsus; all other insects possess double claws in this position. Immatures and adults may possess specialized hinged plates and other structures associated with the anus, concerned with safe disposal of sugary honeydew, but never possess a vasiform orifice or lingula. Apart from a very few Margarodidae, the stages that possess legs all have single-segmented tarsi. Adults are strongly sexually dimorphic; the ephemeral males have one pair of membranous wings (the hind-wings are reduced to hamulohalteres) and lack mouthparts; they are short-lived and seldom seen. Adult females are larviform (neotenous) and sedentary or sessile; adult females and immature stages of both sexes secrete a waxy covering over themselves.

Reproduction is usually sexual but parthenogenesis occurs in some species; hermaphrodity has been recorded. Ovipary, ovovivipary and vivipary occur; the eggs lack a peduncle and are laid under the protective scale cover or in a waxy ovisac produced by the female. There are two to four immature stages in the female and four in the male. Immature and adult females normally feed at least intermittently, but only the first two male instars feed.

Kingdom Animalia
Informal grouping Arthropoda
Phylum Uniramia
Superclass Hexapoda
Class Insecta
Infraclass Pterygota
Division Neoptera
Subdivision Paraneoptera
Order Hemiptera
Suborder Sternorrhyncha
Superfamily Coccoidea

Vernacular name
scale insects (English)
cochenilles (French)

Ben-Dov, Y., 1990c. 1.1.4.4 Classification of diaspidoid and related Coccoidea. In: D. Rosen (ed.), Armoured scale insects, their biology, natural enemies and control. Vol. 4A. World Crop Pests. Elsevier, Amsterdam, the Netherlands: 97-128.

Ben-Dov, Y., 1990g. 1.1.1 Diagnosis and phylogenetic relationships. In: Rosen, D. (ed.), Armoured scale insects, their biology, natural enemies and control. Vol. 4A. World Crop Pests. Elsevier, Amsterdam, the Netherlands: 3-4.

Cook, L., Gullan, P. and H. Trueman, 2001. A putative molecular phylogeny of nine scale insect "families" and its implications. Entomologica 33 (1999): 166.

Danzig, E.M., 1980. Coccids of the far-eastern USSR. (In Russian.) Nauka, Leningrad, Russia. 367 pp. English translation, 1986. United States Department of Agriculture. Amerind Publishing Co, New Delhi, India. 450 pp.

Dolling, W.R., 1991. The Hemiptera. Natural History Museum Publications. Oxford University Press, Oxford, UK. 274 pp.

Gill, R.J., 1993. The scale insects of California. Part 2 The minor families (Homoptera: Coccoidea). Margarodidae, Ortheziidae, Keriidae, Asterolecaniidae, Cerococcidae, Aclerdidae, Kermesidae, Dactylopiidae, Eriococcidae, and Phoenicococcidae. Technical Series in Agricultural Biosystematics and Plant Pathology No. 2. California Department of Food and Agriculture, Sacramento, California, USA. 241 pp.

Gullan, P.J. and M. Kosztarab, 1997. Adaptations in scale insects. Annual Review of Entomology 42: 23-50.

Gullan, P.J. and D.R. Miller, 2002. Do we need to change the rank of scale insects (Hemiptera: Sternorrhyncha: Coccoidea)? Bollettino di Zoologia agraria e Bachicoltura 33 (3): 215.

Kosztarab, M. and F. Kozár, 1988. Scale insects of Central Europe. Akademiai Kaido, Budapest, Hungary. 456 pp.

Kosztarab, M., 1996. Scale insects of north-eastern North America. Identification, biology, and distribution. Virginia Museum of Natural History, Martinsville, Virginia, USA. 650 pp.

Kozár, F. and J. Walter, 1985. Check-list of the Palaearctic Coccoidea (Homoptera). Folia Entomologica Hungarica 46: 63-110.

Kozár, F., 1998 (ed.), Catalogue of Palaearctic Coccoidea. Hungarian Academy of Sciences. Akaprint Nyomdaipari Kft., Budapest, Hungary. 526 pp.

Lambdin, P.L., 2002. Discourse on the classification of the scale insects. Bollettino di Zoologia agraria e Bachicoltura 33 (3): 209-213.

Miller, D.R. and C.J. Hodgson, 1997. 1.1.3.7 Phylogeny. In: Y. Ben-Dov and C.J. Hodgson (eds), Soft scale insects: their biology, natural enemies and control. Vol. 7A. Elsevier, Amsterdam, the Netherlands: 229-250.

Miller, D.R., Ben-Dov, Y. and G.A.P. Gibson, 2001. Scalenet: a searchable information system on scale insects. Proceedings of the ISSIS VIII International Symposium on Scale Insect Studies held at Wye, UK, August 31st - September 6th 1998. Entomologica 33: 37-46. [See also ScaleNet, 1998]

Ouvrard, D., Campbell, B.C., Bourgoin, T. and K.L. Chan, 2000. 18S RNA secondary structure and phylogenetic position of Peloriidae (Insecta, Hemiptera). Molecular Phylogenetics and Evolution 16 (3): 403-417.

ScaleNet, 1998. [Information on Coccoidea, organized by scale insect family, is searchable at a site on the World Wide Web called ScaleNet, http://www.sel.barc.usda.gov/scalenet/scalenet.htm - see also Miller et al., 2001]

Schaefer, C.W., 1996. Introduction. In: C.W. Schaefer (ed.), Studies on hemipteran phylogeny. Thomas Say publications in entomology: proceedings. Entomological Society of America, Lanham, Maryland, USA: 1-8.

Sweet, M.H., 1996. Comparative external morphology of the pregenital abdomen of the Hemiptera. In: C.W. Schaefer (ed.), Studies on hemipteran phylogeny. Thomas Say publications in entomology: proceedings. Entomological Society of America, Lanham, Maryland, USA: 119-158.

Tang, F.T., 1977. The scale insects of horticulture and forest of China. Vol. I. (In Chinese.) Institute Gardening-Forestry Science, Shenyang, Liaonyang, China. 259 pp.

Williams, D.J. and G.W. Watson, 1990. The scale insects of the tropical South Pacific region. Part 3 The soft scales (Coccidae) and other families. CAB International, Wallingford, UK. 266 pp.

Williams, D.J., 1991. Superfamily Coccoidea. In: I.D. Naumann (ed.), The insects of Australia. Second edition. Volume I. Division of Entomology, Commonwealth Scientific and Industrial Research Organisation. Melbourne University Press, Victoria, Australia: 457-464.

Yang, P.L., 1982. A synopsis of Chinese scale insects. (In Chinese.) Shanghai Scientific and Technical Publishing Company, Shanghai, China. 425 pp.