Pediculus coffeae, Linnaeus, 1767

Williams, D. J. & Z. - Q, 2007, Carl Linnaeus and his scale insects (Hemiptera: Coccoidea) *, Zootaxa 1668 (1), pp. 427-490 : 444-449

Pediculus coffeae

When citing Leder., 1762. t. 9., under Coccus adonidum, Linnaeus (1767) added the name Pediculus coffeae as though Ledermüller had proposed the name. Ledermüller only discussed a species under the name Koffeebaumlauss and never named the species as Pediculus coffeae. Because Linnaeus associated the name Pediculus coffeae with the reference to Ledermüller’s illustration, the name Pediculus coffeae was made valid, although unintentionally, and at the same time became a synonym of Coccus adonidum . The specific name coffeae Linnaeus , as published in the binomen Pediculus coffeae , was suppressed under the plenary powers and placed on the Official Index of Rejected Names in Zoology (Name Number 1118) by Melville (1983).

Coccus coryli (Family Coccidae )

Apparently no original specimens of this species exist but the name Coccus coryli was made valid by Linnaeus by citing the excellent figures 4–10 on plate 3 in Réaumur (1740). Linnaeus stated that the species lived on Corylus avellana and, for some time, the name Coccus coryli was accepted by scale insect workers for a species in the family Coccidae , often as Eulecanium coryli (L.). Coccus coryli was also listed by Linnaeus (1761: 265) as living in Sweden on Corylus avellana. The name Coccus coryli could easily have been accepted in place of Lecanium corni Bouché , described by Bouché (1844) but the specific name coryli Linnaeus, 1758 , as published in the binomen Coccus coryli , was suppressed under the plenary powers of the International Commission on Zoological Nomenclature and placed on the Official Index of Rejected and invalid Species Names in Zoology with the Name Number 1141 by Melville (1985).

Coccus hesperidum (Family Coccidae )

( Figure 4 )

Description

In life, adult female elongate to broadly oval, normally fairly flat but sometimes slightly convex, ranging in colour from green to brown.

Diagnostic characters of slide-mounted adult females, normally membranous, with a few small dorsal areolations. Antennae each usually with 7 segments. Legs well developed, each with a tibio-tarsal articulation and a small but well-developed articulatory sclerosis. Claw without a denticle. Anal plates together quadrate, each plate with 4 apical setae. Stigmatic clefts small, each with 3 stigmatic setae, middle seta about 4 times as long as lateral setae.

Dorsal surface with short spine-like setae, each usually with parallel sides then tapering gradually to blunt apex. Minute ducts present associated with areolations. Minute flat pores scattered. Preopercular pores, each a little larger than dorsal pores, present in a small elongate group anterior to anal plates. Tubular ducts either absent or present submarginally. Dorsal tubercles present around submargins.

Ventral surface with marginal setae slender, apically fimbriate, some setae pointed. Prevulvar setae long and flagellate, present as 3 pairs; other setae shorter. Multilocular disc pores concentrated in vulvar region and a few present anteriorly. Minute ducts scattered. Quinquelocular pores usually present in single rows in stigmatic furrows. Tubular ducts each with slender filament, sparsely present between procoxae and clypeolabral shield, medially to mesocoxae and between mesocoxae and metacoxae.

Comments.

The name Coccus hesperidum was first introduced by Linnaeus in Linnaeus (1746) and, although he never described this insect, the name was validated by the references to descriptions that he quoted in Linnaeus (1758). Of these references, Fn. svec . ( Linnaeus, 1746) adds nothing further to its identity, and the reference to Act. paris. (q.v.) shows a scale insect with many eggs. This description cannot refer to C. hesperidum , an ovoviviparous species, as we know it today. The citations of Frisch. ins. and particularly of Reaum. ins. would qualify to validate the name C. hesperidum .

This species is almost cosmopolitan and is often a pest on greenhouse plants. De Lotto (1959), Gill et al. (1977) and Hodgson (1994) provide full descriptions and the accompanying figure is reproduced from Hodgson (1994) with permission from the author and CABI Publishing. Linnaeus’ species is widely recognised and identified from these publications. For a full synonymy of the species see Ben-Dov (1993).

The name Coccus hesperidum with the Name Number 2939 was designated type species of the genus Coccus under the plenary powers of the International Commission on Zoological Nomenclature by Melville (1985).

Coccus ilicis (Family Kermesidae )

( Figures 1J, 5A )

Description

Adult female at maturity spherical, shiny, smooth, with black wax sometimes reflecting a very deep black cherry colour; spherical or showing a basal cleft around abdominal opening giving it a mulberry shape. Region surrounding abdominal opening covered in a white bloom. Antennae well developed, relatively long, with 6 segments; segment 3 as long as segments 4–6 together. Legs short but large. Tubular ducts numerous, short (after Balachowsky, 1950).

First-instar nymph ( Figure 5A )

Slide-mounted specimens elongate-oval, about 0.5 mm long, 0.28 mm wide. Anal lobes moderately developed, each with a long flagellate apical seta. Antennae each with 6 segments. Legs well developed, each tarsus about 1.5 times longer than tibia. Anal ring with 6 setae, anterior pair longer than others. Dorsal surface with a marginal series of spine-like setae usually totalling 22–24 pairs, arranged singly on margins of each abdominal segment. Ventral setae slender and shorter than dorsal marginal setae except for a pair of spine-like setae on head margin. Trilocular pores present submedially in pairs on abdominal segments and with a single pair present on frons. Quinquelocular pores, each larger than a trilocular pore, present on thorax, with 3 next to each mesothoracic spiracle, and 1 next to each metathoracic spiracle and medially to each coxa.

Comments

I have described the species that most authors regard as Kermes ilicis but when Linnaeus named it as Coccus ilicis it seems clear that he was meaning the species that produces the red dye and known since ancient times as Coccus baphica. Linnaeus (1758) cited references to Garidel (Garid. aixens.), Geoffroy (Geoffr. mat.), and Réaumur (Reaum. ins.), and added Ledermüller (Lederm. mat.) in his later edition ( Linnaeus, 1767), all of whom gave accounts of the species that produces the red dye in Provence, France. Linnaeus also indicated that the host plant was Q uercus coccifera . All the authors that Linnaeus quoted discussed the host plant as either Ilex coccus glandulifera, Ilex coccifera , or Ilex aculeata . These are earlier names for Quercus coccifera as shown by Linnaeus (1753) in his Species Plantarum, the starting point of botanical nomenclature. By then, Linnaeus had listed Quercus ilex and Quercus coccifera as separate species. Furthermore, there is no evidence that Linnaeus named Coccus ilicis after Quercus ilex . He could have named it after Ilex , the name used for some species of oaks by the earlier authors. There was no reason, therefore, why Planchon (1864) should describe the dye-producing species as Chermes vermilio [= Kermes vermilio (Planchon) ] when it could have remained as Coccus ilicis . The only doubt about Linnaeus’ choice of name could be the reference to Garidel, who discussed a species producing red eggs and another producing white eggs, both species illus- trated in his work cited by Linnaeus (1758) as plates 53 and 2. Plate 2 in Garidel (q.v.) follows immediately after plate 53. This was probably the only reason why Planchon described Chermes vermilio and added as a synonym Coccus ilicis L. (pro parte)— Chermes ilicis auct. (pro parte). It would have been easier for Planchon to have accepted Coccus ilicis as the dye-producing species and to name the species producing whitish eggs (as described by Garidel) as a different species which he did under the name Chermes bauhini Planchon [= Kermes bauhini (Planchon) ]. All later authors, Blanchard (1883) and Cardon (1990, 2003) have accepted the name Kermes vermilio as the species producing the red dye. The name Chermes bauhini has long since been synonymised with K. ilicis but is, nevertheless, available. Balachowsky (1950), Borchsenius (1960) and other authors who have discussed the morphology, have also accepted K. vermilio as the dye-producing species living on Quercus coccifera , and Kermes ilicis living on Quercus ilex , even though Linnaeus indicated that the host plant for Kermes ilicis was Quercus coccifera . Both scale insect species are specific to their respective species of oaks even when the trees are adjacent ( Cardon, 1990).

A single mature pinned specimen labelled “ilicis” in Linnaeus’ handwriting, is present in Linnaeus’ collection ( Figure 1J) and this was listed by Jackson (1913a) as no. 6 under Coccus . It would normally be easy to ascertain the identity of this specimen but at present I have thought it prudent not to mount it on a microscope slide because, perhaps, little would be gained from a study of such a mature specimen. There has been no modern revision of most European species of Kermes based on adult females taken immediately after the final moult. When such a study is imminent, it might be a good time to examine this specimen further and to decide on its true identity.

For full synonymy, host plant range, and distribution of Kermes ilicis , see Miller et al. (2005). The accompanying figure of the first-instar nymph of this species is taken from Borchsenius (1960) but it has been reversed to show the dorsum on the left.

Coccus myricae (Family Coccidae )

Linnaeus (1767) gave a good description of this species, sent to him from The Cape of Good Hope, South Africa, on Myrica quercifolia . This plant is now known as Morella quercifolia and is, apparently, the only species in the genus. Specimens fitting Linnaeus’ description are not apparent in his collection and the species has not been identified since in South Africa.

Walker (1852) included the species in Lecanium , and later, Targioni Tozzetti (1866, 1868) listed it under his genus Columnea . Signoret (1872) transferred the species to Ceroplastes as C. myricae (L.) where it has remained subsequently in catalogues, even though it is still regarded as unrecognisable. Although Brain (1920) acknowledged that it had not been found again in South Africa since it was described, Jan Giliomee, University of Stellenbosch, South Africa, has informed me that specimens have now been found on Morella quercifolia which might agree with Linnaeus’ description, and work is now in progress to describe the specimens. Although this species has remained unrecognisable, it is remarkable how Cockerell (1893) recorded it from Jamaica, and Green (1900) discussed it as occurring in Assam and Calcutta in India!

Coccus oxyacanthae (Family Coccidae )

This species is not represented in Linnaeus’ scale insect collection. Linnaeus listed it as living on Crataegus oxyacantha and the name was made valid by his reference to two figures by Réaumur (1740) showing good illustrations of an unmistakeable species typical of Pulvinaria and later known as P. oxyacanthae (L.). Using host-transference methods, it has been shown by Malumphy (1991) and Łagowska (1996) that the species is nothing more than P. vitis (L.), thus verifying an earlier synonymy by Newstead (1903).

For some reason, Fabricius (1775) listed Coccus crataegi with the same reference to Linnaeus (1767) and with the same information supplied by Linnaeus for Coccus oxyacanthae . The name C. crataegi Fabricius is an unjustifiable replacement name for C. oxyacanthae and the name C. crataegi Fabricius falls as another synonym of Pulvinaria vitis (L.). Fernald (1903) even credited the authorship of C. crataegi to Linnaeus, as did Ben-Dov (1993), but Linnaeus never mentioned this combination. The error may be a misinterpretation of Linnaeus’ short description of the habit immediately after his listing of the name C. oxyacanthae with the words “ C. Crataegi Oxyacanthae” which means “ Coccus of Crataegus oxyacantha ”, exactly the same earlier Latin description in Linnaeus (1758).

Figures

FIGURE 4. Coccus hesperidum L. Adult female.

FIGURE 5 A. Coccus ilicis L. First-instar nymph. (Now Kermes ilicis (L.)) B. Coccus quercus L. First-instar nymph. (Now Kermes quercus (L.)).