Belongs within: Coccoidea.
Contains: Lecanium, Coccus.
The Coccidae, soft scales, are characterised by the presence in females of paired triangular or rounded plates at the base of an anal cleft. They include both wax-covered and naked species. Several species are significant crop pests such as the hemispherical scale Saissetia coffeae and the soft wax scale Ceroplastes destructor. The red wax scale Ceroplastes rubens attacks a wide range of tree species, including many fruit trees. Pulvinaria elongata is a pest of sugar cane (Carver et al. 1991).
Soft yet scaly
Published 7 December 2009
The truly bizarre insects known as scales have been covered at this site previously, including a brief description of the scale life cycle. In that post I referred to the ensign scales or Ortheziidae; in this post I’ll cover the soft scales or Coccidae. The Coccidae include about 1000 species, some of which produce a dorsal covering of wax while others lack a dorsal covering (Carver et al. 1991). While ortheziids belong to the group of scale families known as archaeococcids, coccids belong to the more derived grouping known as neococcids. Neococcids are distinguished from archaeococcids by the absence of spiracles on the abdomen, and of compound eyes in the adult males (instead, male neococcid eyes have become reduced to dissociated ocelli). Coccids are distinguished from other neococcid families by the presence of a pair of rounded or triangular plates at the base of the anal cleft (Carver et al. 1991).
Another distinctive feature of neococcids is something referred to as Paternal Genome Loss (PGL—also known as Paternal Genome Elimination). In most neococcid families, males are technically diploid but early in development the chromosomes a male has inherited from its father are all inactivated so that it becomes functionally haploid. When the male produces sperm, these inactivated chromosomes are eliminated from sperm production and only the maternally-inherited chromosomes are passed on to its offspring. The reason for the evolution of PGL remains unknown*, but it appears likely to have evolved among neococcids on a single occasion (Yokogawa & Yahara 2009). True haplodiploidy as found in Hymenoptera, where males are truly haploid as opposed to functionally haploid, has also evolved in scales of the archaeococcid family Margarodidae but is as yet unknown among neococcids despite suggestions that PGL may be a precursor to the origin of haplodiploidy. It is worth noting that, while an origin of haplodiploidy from PGL may seem reasonably intuitive, there is the small problem that there are more than twice as many known cases of taxa evolving haplodiploidy as PGL.
*Endosymbiotic bacteria such as Wolbachia have been shown to cause PGL in some insects (and the presence or absence of endosymbionts has been shown to affect PGL in at least one neococcid); alternatively, it could result from genetic factors on the animal’s own X chromosome promoting the transmission of maternal chromosomes.
Systematics of Coccidae
Characters (from Carver et al. 1991): Female with paired triangular or rounded anal plates at the base of an anal cleft; anterior and posterior thoracic spiracles approximately the same size; spiracular and marginal setae present; tubular ducts with inner end cupped.
<==Coccidae [Lecaniidae]
|--LecaniinaeH01b
| |--LecaniumG25
| `--PseudokermesH01b
| |--P. armatusM96
| `--P. nitensH01b
|--Coccinae [Coccini]A73
| |--CoccusL58
| `--SaissetiaA73
| |--S. coffeaeCGW91 [=Lecanium coffeaeB88]
| |--S. hemisphaerica (Targioni 1867) [=Lecanium hemisphaericum]A73
| |--S. mirandaM96
| |--S. neglectaM96
| |--S. nigraB88
| |--S. oleaeB88
| `--S. tolucanaM96
`--Ceroplastes [Ceroplastinae]A73
|--C. actiniformis Green 1896A73
|--C. africanus [incl. C. africanus var. cristatus Green 1899, C. egbarum Cockerell 1899]G00
|--C. albolineatusM96
| |--C. a. albolineatusM96
| `--C. a. volcanicusM96
|--C. amazonicus Hempel 1901H01c
|--C. angulatusM96
|--C. brachyurusM96
|--C. ceriferusB88
|--C. chrysanthemumG17
|--C. cirripediformisM96
|--C. cistudiformisM96
|--C. coloratusM96
|--C. communis Hempel 1901H01c
|--C. destructorCGW91
|--C. dugesiiM96
|--C. floridensisM96
|--C. grandis Hempel 1901H01c
|--C. irregularisM96
|--C. macgregoriM96
|--C. marmoreusM96
|--C. minutusM96
|--C. novaesi Hempel 1901H01c
|--C. purpurellusM96
|--C. rubensS07
|--C. rusciB88
|--C. sinensisM96
`--C. variegatus Hempel 1901H01c
Coccidae incertae sedis:
Parasaissetia nigraCGW91
Phenacaspis dubia [=Chionaspis dubia]M27
EulecaniumGE05
|--E. coryliRD77
|--E. patersoniaeGE05
`--E. subaustraleM96
SymonicoccusCGW91
Cryptes baccatusCGW91
PulvinariaM96
|--P. elongataCGW91
`--P. peninsularisM96
Antecerococcus bryoidesK08
Brachyscelis duplexP08
Paralecanium expansumWEE70
Ericerus pelaWEE70
Platycoelostoma Morrison 1923M27
`--*P. compressa [=Coelostomidia compressa]M27
AnoplaspisM27
|--*A. metrosideri [=Lepidosaphes metrosideri]M27
`--A. maskelli Morrison 1922M27
CtenochitonB88
|--C. aztecusM96
|--C. elaeocarpiB88
|--C. perforatusB88
`--C. viridisB88
SolenococcusH01a
|--S. baccharidis Hempel 1901H01a
`--S. tuberculus Hempel 1901H01a
Stigmacoccus Hempel 1901H01a
`--*S. asper Hempel 1901H01a
Apiococcus Hempel 1901H01a
|--*A. gregarius Hempel 1901H01a
|--A. asperatus Hempel 1901H01a
|--A. globosus Hempel 1901H01a
`--A. singularis Hempel 1901H01a
Tectococcus Hempel 1901H01a
`--*T. ovatus Hempel 1901H01a
AkermesM96
|--A. colimaeM96
`--A. townsendiM96
Cardiococcus umbonatumM96
Ceroplastodes dugesiiM96
Inglisia malvacearumM96
KilifiaM96
|--K. acuminataM96
`--K. americanaM96
Megasaissetia inflataM96
MesolecaniumM96
|--M. imparM96
|--M. nocturnumM96
`--M. perditumM96
Metapulvinaria lyciiM96
Milviscutulus mangiferaeM96
NeolecaniumM96
|--N. chilaspidisM96
|--N. herreraeM96
|--N. imbricatumM96
|--N. manzanillenseM96
|--N. plebeiumM96
|--N. salleiM96
`--N. tuberculatumM96
Pendularia jaliscensisM96
PhilephedraM96
|--P. colimensisM96
|--P. crescentiaeM96
|--P. luteaM96
|--P. mimosaeM96
|--P. parvulaM96
`--P. tuberculosaM96
Platysaissetia castilloaeM96
Protopulvinaria pyriformisM96
Schizochlamidia mexicanaM96
TillanococcusM96
|--T. mexicanaM96
`--T. tillandsiaeM96
ToumeyellaM96
|--T. ceriferaM96
|--T. mirabilisM96
`--T. sonorensisM96
Insulaspis pallidulaCK15
*Type species of generic name indicated
References
[A73] Ali, S. M. 1973. Some coccids from Goa. Journal of the Bombay Natural History Society 69 (3): 669–671.
[B88] Bouček, Z. 1988. Australasian Chalcidoidea (Hymenoptera): A biosystematic revision of genera of fourteen families, with a reclassification of species. CAB International: Wallingford (UK).
[CK15] Calvo, F. J., M. Knapp, Y. M. van Houten, H. Hoogerbrugge & J. E. Belda. 2015. Amblyseius swirskii: what made this predatory mite such a successful biocontrol agent? Experimental and Applied Acarology 65: 419–433.
[CGW91] Carver, M., G. F. Gross & T. E. Woodward. 1991. Hemiptera (bugs, leafhoppers, cicadas, aphids, scale insects etc.) In: CSIRO. The Insects of Australia: A textbook for students and research workers vol. 1 pp. 429–509. Melbourne University Press: Carlton (Victoria).
[G17] Girault, A. A. 1917. Descriptiones hymenopterorum chalcidoidicarum variorum cum observationibus. V. Privately published (reprinted: Gordh, G., A. S. Menke, E. C. Dahms & J. C. Hall. 1979. The privately printed papers of A. A. Girault. Memoirs of the American Entomological Institute 28: 116–131).
[G25] Girault, A. A. 1925. An essay on when a fly is lovable, the ceremony of baptizing some and unlovely hate. Privately published (reprinted: Gordh, G., A. S. Menke, E. C. Dahms & J. C. Hall. 1979. The privately printed papers of A. A. Girault. Memoirs of the American Entomological Institute 28: 187–190).
[G00] Green, E. E. 1900. Note on Ceroplastes africanus (family Coccidae). Annals and Magazine of Natural History, series 7, 5: 158–159.
[GE05] Grimaldi, D., & M. S. Engel. 2005. Evolution of the Insects. Cambridge University Press: New York.
[H01a] Hempel, A. 1901a. Descriptions of Brazilian Coccidae. Annals and Magazine of Natural History, series 7, 7: 110–125.
[H01b] Hempel, A. 1901b. Descriptions of Brazilian Coccidae (continued). Annals and Magazine of Natural History, series 7, 7: 206–219.
[H01c] Hempel, A. 1901c. Descriptions of Brazilian Coccidae (continued). Annals and Magazine of Natural History, series 7, 7: 556–561.
[K08] Kirkaldy, G. W. 1908. A catalogue of the Hemiptera of Fiji. Proceedings of the Linnean Society of New South Wales 33: 345–391, pl. 4.
[L58] Linnaeus, C. 1758. Systema Naturae per Regna Tria Naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis revised 10th ed. vol. 1. Laurentii Salvii: Holmiae.
[M96] Miller, D. R. 1996. Checklist of the scale insects (Coccoidea: Homoptera) of Mexico. Proceedings of the Entomological Society of Washington 98 (1): 68–86.
[M27] Myers, J. G. 1927. On the nomenclature of New Zealand Homoptera. Transactions and Proceedings of the New Zealand Institute 57: 685–690.
[P08] Palmer. 1908. Notes and exhibits. Proceedings of the Linnean Society of New South Wales 33: 434.
[RD77] Richards, O. W., & R. G. Davies. 1977. Imms’ General Textbook of Entomology 10th ed. vol. 2. Classification and Biology. Chapman and Hall: London.
[S07] Ślipiński, A. 2007. Australian Ladybird Beetles (Coleoptera: Coccinellidae): Their biology and classification. Australian Biological Resources Study: Canberra.
[WEE70] Woodward, T. E., J. W. Evans & V. F. Eastop. 1970. Hemiptera (bugs, leafhoppers, etc.) In: CSIRO. The Insects of Australia: A textbook for students and research workers pp. 387–457. Melbourne University Press.
Yokogawa, T., & T. Yahara. 2009. Mitochondrial phylogeny certified PGL (Paternal Genome Loss) is of single origin and haplodiploidy sensu stricto (arrhenotoky) did not evolve from PGL in the scale insects (Hemiptera: Coccoidea). Genes Genet. Syst. 84: 57–66.