Opisthoscelis ungulifinis Hardy & Gullan

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 : 17-18

Opisthoscelis ungulifinis Hardy & Gullan sp. n. Figs 1l10

Gall

(Fig. 1l). Female. On leaf. Raised, rather nipple-like excrescences; height ca 2 mm above leaf and projecting 1 mm below, width 3-5 mm. Gall opening star-like, with fissures radiating from central orifice, apparently on adaxial leaf surface.

Male. Unknown.

Adult female

(Fig. 10) (n = 7). Body outline circular, with venter broader than dorsum of mature specimens; length 3.0-3.9 mm, greatest width 2.8-3.7 mm; abdomen about as long as head + thorax. Eyespots on dorsum near margin, each 48-58 mm wide. Antennae 3-5 segmented, each 185-230 mm long. Frontal lobes difficult to discern in some specimens, each 330-510 µm long, 185-230 µm wide. Tentorial box 480-530 mm long. Labium 140-155 mm long, 125-175 mm wide. Pump chamber 28-33 µm long, 35-38 µm wide. Spiracles 135-170 mm long, 65-90 mm wide across atrium. Fore and mid legs reduced but segmented, 245-410 µm long. Hind legs slender and elongate; coxa on a fleshy projection, coxa 650-745 µm long, trochanter + femur 820-880 µm long, tibia straight, 645-680 µm long, tarsus 350-410 µm long; claw and digitules present but reduced; translucent pores present on both surfaces of each leg segment except trochanter; each side of trochanter with 3 campaniform sensilla; femur-tibia articulation functional. Anal opening on venter, 58-68 µm wide, anal ring 83-110 µm wide, with 14-20 setae.

Dorsum. Delineated by marginal fringe of elongate (up to 300 µm) flagellate setae, fringe extending from head to abdominal segment IV, margin of each of abdominal segments V–VIII with pair of blunt sclerotic projections at end of short fleshy lamella. Derm densely beset with microtrichia. Dorsal setae flagellate, 15-148 mm long; scattered over dorsum. Macrotubular ducts 14-15 µm long, dermal orifice opening with rim 5 µm wide; ducts in a transverse row across each abdominal segment, scattered over head and thorax. Microtubular ducts 5 µm long, dermal orifice with rim 2 µm wide; distributed evenly over dorsum Quinquelocular pores absent.

Venter. Ventral body surface greatly expanded, posterior abdominal segments only visible from dorsal aspect. Oral lobes membranous. Ventral setae 13-250 mm long, in transverse row across each body segment, scattered along margin. Macrotubular ducts similar to those on dorsum, scattered along margin, in a transverse row across each of abdominal segments II–V. Quinquelocular pores 5 mm in diameter, in a cluster around each spiracle, scattered along margin, in a transverse row across each abdominal segment, most dense around vulva.

Material examined.

Holotype of Opisthoscelis ungulifinis (here designated): AUSTRALIA: South Australia: 1 adult female (3.9 mm long, 3.7 mm wide): ex gall, Eucalyptus?oleosa , 2 km SW of Oodla Wirra, 5 Dec., 1981, PJG (ANIC).

Paratypes: AUSTRALIA: South Australia: 6 adult females, 24 first-instar nymphs: same data as holotype (ANIC).

Comments.

Adult females of Opisthoscelis ungulifinis can be recognised easily by the 1 or 2 blunt spines on each of the marginal projections on the posterior abdominal segments, and by having the hind coxae each set on a fleshy projection. Adult females of Opisthoscelis ungulifinis are also unique amongst Opisthoscelis species in having microtubular ducts. The adult females are most similar to those of Opisthoscelis serrata , which also have marginal projections each with 1 or 2 spines; however these spines are conical in Opisthoscelis serrata . Adult females of Opisthoscelis ungulifinis can be further separated from those of Opisthoscelis serrata by lacking marginal projections cephalad of abdominal segment IV (present on all abdominal segments of Opisthoscelis serrata ), and by having a marginal fringe of elongate setae (absent in Opisthoscelis serrata ).

Etymology.

The species name is a combination of the Latin words ungula, meaning hoof, and finis, meaning end or boundary. It refers to the blunt sclerotic projections at the apex of each marginal lamella. The name is a noun in apposition.