Stibococcus Miller & González

Hodgson, Chris & Miller, Dug, 2010, A Review of the Eriococcid Genera (Hemiptera: Sternorrhyncha: Coccoidea) of South America 2459, Zootaxa 2459 (1), pp. 1-101 : 80-82

Stibococcus Miller & González

Stibococcus Miller & González, 1975: 154–156 .

Type species: Stibococcus cerinus Miller & González, 1975: 156–159 .

Generic diagnosis: Adult female ( Fig. 40 ). In life, forming a characteristic ovisac beneath and behind the body of the adult female on the underside of the leaves of the host. Adult female with small membranous anal lobes, normally not protruding. Dorsum. Setae spinose, of basically 2 sizes: (i) larger setae in a marginal band and a medial line; and (ii) smaller setae elsewhere. Macrotubular ducts with characteristic sclerotised dermal rim, those on dorsum unusually large. Microducts with a narrow sclerotised rim. Loculate pores absent. Margin. Poorly defined. Venter. Setae mainly small and hairlike but those near margin similar to smaller spinose setae on dorsum. Macrotubular ducts of 2 types, both smaller than dorsal type; more or less restricted to posterior half of body; smaller type in large clusters on abdomen. Quinquelocular pores present in submarginal band from head to apex of abdomen, present medially on most abdominal segments. Cruciform pores absent. Antennae 6 segmented. Frontal lobes absent but antennal tubercles present. Labium 1 segmented. Metathoracic legs with translucent pores on coxa, femur and sometimes tibia. Claw digitules similar; claw with a small denticle. Vulva present between segments VII and VIII .

Known only from Myrtaceae .

Comment. Stibococcus is a monotypic genus known only from Chile. For description of the adult female, adult male and pupa of S. cerinus , see Miller & González (1975: 154). Miller & González (1975) indicate that the adult females of this genus differ from all other eriococcid genera by having the following combination of characters: (i) macrotubular ducts with a sclerotized orifice; (ii) clusters of macrotubular ducts present across most abdominal segments; (iii) small anal lobes; (iv) 1 segmented labium; and (v) characteristic ovisac.

Adult male ( Fig. 41 )

Diagnosis. Mounted material. Size about 1 mm long. Loculate pores absent on body; X-type pores present dorsally on head. Body setae hairlike. Head. With 2 pairs of subequal simple eyes. Setae quite abundant on occular sclerite and genae. Dermal reticulations absent. Postoccipital ridge with both anterior and posterior arms. Antennae long, 10 segmented; setae generally longer than width of segment; capitate setae present on apical segment only. Thorax. Prothorax with prosternal setae but no antespiracular setae and no setae dorsally. Meso- and metathorax showing nothing distinctive. Forewings probably without an alar lobe, alar setae and alar sensoria. Hamulohalteres absent. Legs. Well developed; campaniform pores on each trochanter oval and in a line; trochanter setae all short; tarsi two segmented; tarsal digitules capitate; claw without a denticle; claw digitules capitate; fleshy setae not well differentiated. Abdomen. Dorsal abdominal setae few, fewer than ventral abdominal setae; pleural setae in distinct groups; tergites and sternites only present on segment VIII; glandular pouches present, pouch pores tending to spread out of pouch; glandular pouch setae short, slightly capitate. Penial sheath typical of Eriococcidae , divided into two parts, anterior part about half length of penial sheath, parallel-sided, with anus at posterior end; posterior part narrower, narrowing to a sharp apex; setae quite abundant.

Comment. The most distinctive characters of the adult male of S. cerinus are: (i) penial sheath short, only about 1.5x longer than basal width; (ii) 10 segmented antennae, with setae slightly longer than width of segment; (iii) presence of pores on head; (iv) abdominal tergite VIII sclerotised.

Figures

FIGURE 40. Stibococcus cerinus Miller & González. Adult female, where A = dorsal spinose setae; B = dorsal microtubular duct; D = dorsal macrotubular duct; G = dorsal view of anal lobe; K = ventral microtubular duct; L = ventral loculate pores; M1, M2 = ventral macrotubular ducts; R = marginal spinose seta; W = claw or prothoracic leg; X = anal ring, and Z = proximal end of metathoracic leg (modified after Miller & González, 1975).

FIGURE 41. Stibococcus cerinus Miller & González. Adult male, where B = pores on dorsal epicranium; E = dorsal view of penial sheath; F = ventral view of penial sheath; G = loculate pores, and K = claw of mesothoracic leg (modified after Miller & González, 1975). For other abbreviations, see under ‘Figure captions’ on p5