Opisthoscelis serrata Froggatt

Hardy, Nate B. & Gullan, Penny J., 2010, Australian gall-inducing scale insects on Eucalyptus: revision of Opisthoscelis Schrader (Coccoidea, Eriococcidae) and descriptions of a new genus and nine new species, ZooKeys 58, pp. 1-74 : 8-9

Opisthoscelis serrata Froggatt Figs 1d,e,f5

Opisthoscelis serrata Froggatt 1894b: 346-347.

Gall

(Fig. 1d,e,f).Female. On leaf. Height 2.4-7.0 mm, width 2.5-6.6 mm, length of basal attachment 2.4-4.0 mm. Gall opening slit-like ca 2 mm wide, on abaxial leaf surface. Gall spherical, sometimes with a tapered point (Fig. 1d), opening on opposite side of leaf. Mature female filling gall cavity (Fig. 1e).

Male. On leaf. Gall opening oblong, surrounded by a slightly raised lip (Fig. 1f), on abaxial leaf surface; opposite side of leaf with small globose swelling.

Adult female

(Fig. 5) (n = 21). Body outline ovate, length 2.3-5.0 mm, greatest width 1.8-4.3 mm; abdomen about as long as head + thorax. Eyespots set well away from margin, each 28-90 mm wide. Antennae 6-segmented, each 290-490 mm long. Frontal lobes may be difficult to discern, each 225-470 µm long, 150-490 µm wide. Tentorial box 285-480 mm long. Labium 75-155 mm long, 100-168 mm wide. Pump chamber 25-28 µm long, 23-30 µm wide. Spiracles 68-195 mm long, 48-85 mm wide across atrium. Fore and mid legs reduced but segmented, 43-160 µm long. Hind legs slender and elongate; coxa 300-590 µm long; trochanter + femur 480-940 µm long; tibia straight, 460-1000 µm long; tarsus 180-280 µm long; claw and digitules present but reduced; few translucent pores scattered on femur, tibia and tarsus; femur-tibia articulation functional. Anal opening ventral, set in shallow membranous invagination, 30-55 µm wide; anal ring plate-like, 63-128 µm wide, with 6-18 setae.

Dorsum. Head with shield of rugose, sclerotic cuticle, 600-1000 µm long, 450-1100 µm wide; each side of abdomen with segmental pairs of marginal spines, each spine at end of fleshy projection, these larger on posterior segments; each thoracic segment with a few similar structures along the margin; marginal fringe of elongate setae absent. Derm densely beset with microtrichia. Dorsal setae minute, 4-8 mm long; scattered over dorsum. Macrotubular ducts 12-15 µm long, rim of dermal orifice 5 µm wide; ducts in a transverse row across each body segment. Microtubular ducts absent. Quinquelocular pores absent.

Venter. Oral lobes membranous. Ventral setae 5-115 mm long, in transverse row across each abdominal segment, a medial to submedial cluster on each thoracic segment, scattered along margin, longer setae found in medial areas. Macrotubular ducts similar to those on dorsum, scattered along margin, in a transverse row across each of abdominal segments II–IV. Quinquelocular pores 5 mm in diameter, in cluster around each spiracle, along margin of abdomen, in a transverse band across each posterior margin of abdominal segments IV–VIII.

Material examined.

Lectotype of Opisthoscelis serrata (here designated): AUSTRALIA: Victoria: 1 adult female (damaged, ca 3.0 mm mm long, 2.7 mm wide), on slide with another adult female, lectotype farthest from data label; original label: "Opisthescelis[sic] serrata / ♀ galls on Euc. Adult in / spirit. Slide in coll. / Bendigo W.W.F. / Damage in Box 284" ASCTHE101344 (ASCU).

Paralectotypes: AUSTRALIA: Victoria: 1 adult female, same data and slide as lectotype (ASCU); dry galls (6 of female and 4 of male), all parasitised or empty, with printed label: "3046 E / GALL MAKING COCCIDS, / Opisthoscelis serrata , Frogtt. / Female galls upon Eucalyptus sp. / Bendigo, Victoria." ASCT00004861 (ASCU).

The lectotype and associated paralectotype are in poor condition and were mounted from the spirit collection in ASCU by PJG in 1985; additional females, in poor condition, remained in the vial; no original WWF slide-mount was located.

Additional material:

AUSTRALIA: New South Wales: 5 adult females, 5 second-instar females: ex galls on leaves, Eucalyptus largiflorens , Kinchega National Park, 2 July, 1984, J. M. Smith (ANIC). South Australia: 9 adult females: ex galls, Eucalyptus microcarpa , Aldinga Beach, 2 Oct., 1965, HMB, Specimen Index No. 44/65 (ANIC); 5 adult females, 6 second-instar females: ex globular galls on leaves, Eucalyptus odorata [may be misidentification of Eucalyptus microcarpa ], Wilmington, 7 Sep., 1982, F. D. Morgan, Specimen Index No. 19/82 (ANIC). Victoria: 7 adult females: ex galls on leaves, Eucalyptus?microcarpa , ca 10 km S of Nagambie, just E of railway line, -36.37°; 145.17°, 7 Feb., 2004, PJG (ANIC); 2 adult females: ex galls on leaves, Eucalyptus microcarpa , ca 10 km S of Nagambie, on road to Avenel, near railway line, -36.38°; 145.17°, 30 Jan., 2005, PJG, NH26 (ANIC); 2 adult females: ex galls on leaves, Eucalyptus melliodora , ca 9 km N of Nagambie, on Goulburn Weir Road, -36.72°; 145.18°, 30 Jan., 2005, PJG, NH24 (ANIC); 4 adult females: ex galls on leaves, Eucalyptus polyanthemos , Melbourne, North Warrandyte, corner of Overbank Road and Glynns Road, -37.73°; 145.20°, 14 Feb., 2005, PJG & NBH (ANIC, NMV); 2 adult females: Eucalyptus polyanthemos , Melbourne, Warrandyte, behind 134 Brackenbury Street, 7 May, 1977, PJG (ANIC).

Comments.

Adult females of Opisthoscelis serrata can be recognised easily by (1) the shield of rugose sclerotic cuticle on the dorsal surface of the head, and (2) the pair of marginal spine-tipped fleshy projections on each side of each abdominal segment. Both of these features are unique amongst Opisthoscelis and Tanyscelis species. Opisthoscelis serrata is known only from eucalypt species in the section Adnataria . There is some variation in the shape and size of the gall of the adult female, which is basically globular. Galls on leaves of Eucalyptus largiflorens and Eucalyptus polyanthemos protrude as a sphere on one side of the leaf, although some galls from leaves of Eucalyptus polyanthemos at Warrandyte have a pointed apex (Fig. 1d). In contrast, galls from the leaves of Eucalyptus melliodora and Eucalyptus microcarpa from near Nagambie protrude equally from both leaf surfaces and the females are smaller than those from most other localities. Females from all galls look similar, although differing in size.