Exallococcus Miller & González, 1976

Hodgson, Chris & Miller, Dug, 2010, A Review of the Eriococcid Genera (Hemiptera: Sternorrhyncha: Coccoidea) of South America 2459, Zootaxa 2459 (1), pp. 1-101 : 45-48

Exallococcus Miller & González

Exallococcus Miller & González 1975: 148 .

Type species: Exallococcus laureliae Miller & González 1975: 150–152 .

Generic diagnosis. Adult female ( Fig. 20 ). Found on leaves of host plant. Body oval, widest medially. Dorsum. Derm membranous, segmentation indefinite. Dorsal setae primarily spinose, straight or slightly curved, subequal in size; with a few hair-like setae in medial and mediolateral areas. Macrotubular ducts with sclerotised dermal orifice. Microtubular ducts abundant. Loculate pores absent. Simple pores abundant over surface. Anal lobes heavily sclerotised, with small teeth near apex. Median plate weakly sclerotised. Anus apparently invaginated between anal lobes, difficult to discern, apparently with a small sclerotised ring, few pores, and 4 pairs of setae. Margin. Marginal setae same size as dorsal spinose setae. Venter. Derm membranous. Setae on abdomen weakly spinose, those in medial areas of head and thorax more hairlike. Macro- and microtubular ducts absent. Loculate pores usually with 5 loculi, arranged in distinct pattern, forming longitudinal line in submedial area of head, thorax, and abdomen. Cruciform pores present on lateral areas of head, thorax and anterior abdominal segments. Antenna 6 segmented. Frontal lobes present but antennal tubercles absent. Labium probably 3 segmented. Legs each well developed; each hind coxa swollen, with numerous large pores on each surface, without microspinules; hind femur swollen, with numerous large pores on dorsal surface; tibiae each with 3 setae; tarsi each with 4 setae; claws short and broad, each with digitules equal in size and longer than claw; each claw with a denticle near apex. Vulva present between segments VII and VIII.

Known only from Antherospermataceae.

Comment. Exallococcus is a monotypic genus known only from Chile. Adult females of Exallococcus species can be separated from other South American eriococcid adult females by the presence of: (i) an invaginated anal ring; (ii) antennal segments rather long and narrow; (iii) anal lobes heavily sclerotised with a longitudinal fold; (iv) macrotubular ducts on dorsum only; (v) labium 1 segmented; and (vi) dorsum with many simple pores.

First-instar nymph (sex not determined) ( Fig. 21 )

Diagnosis. Mounted material. Body oval, more pointed at posterior end. Dorsum. Dorsal setae of 2 sizes: enlarged setae spinose, in 2 lines medially and forming a marginal line, and small setae very small, hairlike, mainly in a submedian line and a submarginal line. Macrotubular ducts absent. Microtubular ducts small, scattered. Simple pores present, scattered. Anal lobes sclerotised, each with a longitudinal fold and 2 thick spinose setae on inner margin and another on outer margin, plus longer apical seta. Median plate present. Margin. Delineated by band of enlarged dorsal setae. Venter. Setae of 2 types: those near margin slightly spinose, those more medially hairlike. Macrotubular ducts absent. Microtubular ducts restricted to near margin. Loculate pores, each with 5 loculi, present in a longitudinal band mediolaterally. Cruciform pores few, submarginal on anterior abdominal segments and thorax. Antennae 6 segmented. Labium 1 segmented. Legs without pores; tarsus much longer than tibia; tarsal digitules capitate; claw with a denticle; claw digitules similar both with small capitate apices.

Comment. The first-instar nymph of Exallococcus is somewhat similar to that of Chilechiton lynnae in having a longitudinal fold in each anal lobe but is otherwise easily separated by the shape and distribution of the dorsal setae, the distribution of the ventral loculate pores, the presence of cruciform pores and in having both claw digitules similar.

For a description of the adult female and first-instar nymph of E. laureliae , see Miller& González, 1975: 150.

Figures

FIGURE 20. Exallococcus laureliae Miller & González. Adult female. Where A = dorsal seta; B = dorsal microtubular duct; C = dorsal simple pores; D = dorsal macrotubular duct; J = ventral setae; L = ventral loculate pore; P = anterior spiracle; R = marginal spinose seta; U = cruciform pore; W = claw of prothoracic leg; X = suranal seta, and Z = coxa of metathoracic leg (modified after Miller & González, 1975).

FIGURE 21. Exallococcus laureliae Miller & González. First-instar nymph, where A = dorsal seta, B = dorsal microtubular duct; C = dorsal simple pores; J = ventral setae; J1 = spinose submarginal ventral seta; K = ventral microtubular ducts; L = ventral loculate pore; R = marginal spinose seta; U = cruciform pore; W = claw of metathoracic leg; X = suranal seta (modified after Miller & González).