Coccus rusci, Linnaeus, 1758

Williams, D. J. & Z. - Q, 2007, Carl Linnaeus and his scale insects (Hemiptera: Coccoidea) *, Zootaxa 1668 (1), pp. 427-490 : 454-456

Coccus rusci (Family Coccidae ) [now known as Ceroplastes rusci (L.)]

( Figure 8 )

Description

In life, adult female covered in a thick waxy symmetrical test, white, tinged with red.

Adult female on microscope slide, broadly oval, fairly membranous except for short conical sclerotized anal process. Antennae 6 segmented, segment 3 longest. Legs well developed, tibia and tarsus divided, with a small articulatory sclerosis. Claw with a minute denticle and a pair of expanded digitules. Anal plates together quadrate, anterior margins shorter than almost parallel sides, each plate with 3 setae posteriorly. Anal ring with 6 setae.

Dorsal surface with minute, blunt setae, scattered. Minute pores present, each usually with contiguous smaller pore, fairly numerous. Other minute pores present, simple.

Ventral surface with poorly developed stigmatic clefts, each cleft with anterior and posterior rows of short conical setae, rows almost touching on mesothorax. Other marginal and medial setae flagellate. Multilocular disc pores present around vulvar region and at least on preceding abdominal segment. Quinquelocular pores forming wide bands between spiracles and stigmatic clefts. Tubular ducts present in small groups anteromedially to antennal bases and 1 or 2 present medially on abdomen. Microducts present, abundant.

Comments

This species is commonly known as the fig wax scale. There are no apparent specimens in Linnaeus’ collection. Linnaeus (1758) gave a good description of this scale insect leaving little doubt about its identity. He also cited earlier works by other authors and these contain either short descriptions or illustrations, often described as small molluscs, to which the insect resembles, but found on Myrtus and Ruscus . Linnaeus described the species from Apulia, Italy, but it is now common throughout the Mediterranean area and elsewhere ( Ben-Dov, 1993) on many plants. This scale insect is currently placed in the genus Ceroplastes Gray where it was transferred by Signoret (1872). One of its many synonyms is Coccus caricae Fabricius , the type species of Columnea Targioni Tozzetti , a genus named after Fabio Colonna when Latinised, an author that Linnaeus cited. Hodgson (1994) has illustrated and described this species in the combination Columnea rusci (L.), the work from which the accompanying illustration is taken by kind permission of the author and CABI Publishing.

For full synonymy of this species see Ben-Dov (1993) and for a full description of the adult female see Hodgson (1994) and Pellizzari & Camporese (1994). There are also many synonyms of the genus Ceroplastes but Qin & Gullan (1995) have shown by cladistic analysis that Ceroplastes is a monophyletic group that includes all so-called wax scales. Although these authors did not include Columnea , nevertheless, they did include Ceroplastes rusci in their analysis and the species should probably remain in this combination.

Figures

FIGURE 8. Coccus rusci L. Adult female. (Now Ceroplastes rusci (L.)).