Opisthoscelis subrotunda Schrader

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 : 9-13

Opisthoscelis subrotunda Schrader Figs 1g,h,i67

Opisthoscelis subrotunda Schrader 1863: 7.

Opisthoscelis globosa Rübsaamen 1894: 214; synonymy by Froggatt 1894a: 209.

General.

Schrader (1863) described and illustrated Opisthoscelis subrotunda based on insects and galls from an unidentified Eucalyptus sp. collected in New South Wales. Schrader’s collection was destroyed on July 30, 1943, during WWII according to Ew. Weidner in personal communication to PJG ( Gullan 1984a). Rübsaamen (1894) described a number of Australian gall-inducing insects, including Opisthoscelis globosa from Eucalyptus in New South Wales, while his address was “Königlichen Museum für Naturkunde zu Berlin". We contacted Museum für Naturkunde Leibniz-Institut für Evolutions- und Biodiversitätsforschung an der Humboldt-Universität zu Berlin, but were told that there was no Opisthoscelis material from Rübsaamen in that collection, and thus we believe that Rübsaamen’s material also was destroyed during WWII, as suggested by Gullan (1984a). The synonymy of Opisthoscelis subrotunda and Rübsaamen’s Opisthoscelis globosa was proposed by Froggatt (1894a) but not accepted by Hoy (1963); subsequent authors have followed Hoy, although Miller and Gimpel (2000) stated that the status of these two species needed further study. Here we accept Froggatt’s (1894a) synonymy of these two species based on the perfect match of Schrader’s and Rübsaamen’s descriptions and illustrations of the insects and their galls. There is only one species in New South Wales that exactly matches Schrader’s and Rübsaamen’s descriptions. Thus we are certain of the identity of Opisthoscelis subrotunda and consequently have not designated a neotype.

Gall

(Fig. 1g,h,i). Female. On leaf. Gall globose (Fig. 1g), surface punctate, leaf glands enlarged on gall. Gall height 4.0-8.7 mm, width 4.2-9.5 mm, length of basal attachment 3.0-6.8 mm; wall of gall at least 2 mm thick in most mature galls. Gall opening variable, slit-like, cruciform (Fig. 1h) or round, sometimes with “lips” projecting, 0.1-2.5 mm wide; opening on abaxial or adaxial surface, but usually on same surface on any one leaf or plant. Mature female fills gall cavity with her abdominal apex directed towards and plugging gall orifice.

Male. On leaf. Gall conical (Fig. 1i), distal margin entire, opening oblong to round, 0.5-2.2 mm wide. Gall height 1.4-4.1 mm, width 1.1-3.6 mm, length of basal attachment 1.3-3.7 mm.

Adult female

(Fig. 6) (n = 30). Body outline ovate, length 2.1-4.8 mm, greatest width 1.5-4.0 mm; abdomen about as long as head + thorax. Eyespots on margin, each 40-60 mm wide. Antennal segmentation poorly developed; each antenna 50-160 mm long. Frontal lobes sometimes difficult to discern, each 140-280 µm long, 100-240 µm wide. Tentorial box 260-560 mm long. Labium 70-140 mm long, 70-160 mm wide. Pump chamber 26-33 µm long, 28-33 µm wide. Spiracles 90-180 mm long, 50-120 mm wide across atrium. Fore and mid legs reduced but segmented, 115-360 µm long. Hind legs slender and elongate; coxa 370-640 µm long; trochanter + femur 520-950 µm long; tibia 420-1020 µm long; tarsus 110-170 µm long; claw and digitules present but reduced; translucent pores on both surfaces of tibia and tarsus; femur-tibia articulation functional. Anal opening ventral, set in shallow membranous invagination, 38-83 µm wide; anal ring 65-120 µm wide, with 8-16 setae.

Dorsum. Delineated by fringe of spinose setae along margin, each seta similar to those on rest of dorsum; cauda composed of two truncate fleshy projections on each side of body, each bearing ca 4-6 spinose setae. Derm variously sclerotic, densely beset with minute papillae. Dorsal setae spinose, 20-138 mm long, with stout, or swollen bases. Microtubular ducts absent. Quinquelocular pores absent.

Venter. Oral lobes membranous. Venter hirsute, each seta 23-163 mm long, absent from medial areas of head and pro- thorax, plus antero-medial portion of mesothorax. Macrotubular ducts 10-12 µm long, dermal orifice with rim 5 µm wide; ducts restricted to abdomen, scattered. Quinquelocular pores 5-8 mm in diameter; clustered around each spiracle, and on medial areas of abdomen.

First-instar nymph

(Fig. 7) (n = 4). Body outline elliptical, anterior margin incised at midline; length 288-308 µm, greatest width 180-198 µm. Eyespots on margin, each 10-11 mm wide. Antennae 4-segmented, each ca 75 mm long. Tentorial box 55-63 mm long. Labium 25-28 mm long, 28-33 mm wide. Spiracles 13-19 mm long, 8 mm wide across atrium. Each leg: coxa 23-28 µm long, with 5 setae; trochanter + femur 60-66 µm long, trochanter with 4 setae, femur with 4 setae; tibia 38 µm long, with 4 setae; tarsus 38-40 µm long, with 4 setae; claw 15-18 µm long; tarsal digitules capitate, unequal length, short digitule 23-24 µm long, long digitule 28-33 µm long, claw digitules capitate, each 15-18 µm long. Anal ring 15-16 µm wide, with 6 setae, each ca 13-18 µm long. Apical seta 135-183 µm long.

Dorsum. Derm membranous. Dorsal setae ca 3 mm long; arranged in submedial longitudinal row on each side of body, 1 seta on each side of head, each thoracic segment, and each or any of abdominal segments I–III and V. Microtubular ducts 4 µm long, on each side of body: 1 duct on submargin of each side of each thoracic segment plus usually each of abdominal segments I, V and VIII. Marginal setae cylindrical, with hemispherical base with diameter> width of cylinder, distal edge of base flat, each marginal seta 2-5 µm long; each side of body with ca 6 setae between midline and eyes, 9 on prothorax, 5 on mesothorax, 3 on metathorax, 2 on each of abdominal segments I–VII, and on abdominal segment VIII 1 lateral and 2 medial of apical seta (these 3 probably homologous to anal lobe setae), with setae medial of apical seta robust, each with truncate apex.

Venter. Setae hair-like, 2-23 mm long, each side of body with 3 setae medial of scape, 1 seta medial of each coxa, 3 longitudinal rows on abdomen, each row with 1 seta on each of abdominal segments II–VII; suranal and ventral lobe setae hair-like, each 18-25 µm long. Trilocular pores 2 µm in diameter, 1 pore near each spiracle.

Material examined.

AUSTRALIA: Australian Capital Territory: 3 adult females: Eucalyptus sp., Canberra, Bruce, 23 Sep., 1972, H. J. Banks (ANIC). New South Wales: 1 adult female: ex leaf gall, Eucalyptus blakelyi , 26 km N of Canowindra, 14 km S of Cudal, -33.41°; 148.69°, 13 Aug., 2004, NBH and PJG, NH21 (ANIC); 13 adult females: ex galls on leaves, Eucalyptus longifolia , 8.5 km SSE Moruya, Bingie Road, -35.97°; 150.12°, 7 Jan., 1992, PJG (ANIC); 5 adult females, 3 second-instar females, 2 first-instar nymphs: ex galls on leaves, Corymbia gummifera , Bundeena, roadside, 14 Feb., 2004, C. A. M. Reid and PJG, NH84 (ANIC); 5 adult females: ex leaf, Eucalyptus longifolia , Congo, 4 Jan., 1992, PJG (ANIC); 2 adult females: ex galls on leaves, Eucalyptus sp., Congo, Congo Road, -35.95°; 150.15°, 8 Jan., 1992, PJG (ANIC); 10 adult females: Sydney (ASCU); 1 adult female: ex leaf gall, Eucalyptus sp., Toolom, near Toolom Falls on edge of Yabbra State Forest, -28.52°; 152.53°, 22 Aug., 2004, NBH and PJG, NH23 (ANIC); 7 adult females (2 slides): Eucalyptus robusta , Sydney Harbour, W. W. Froggatt #1868 (ANIC); 4 adult females (2 slides): Eucalyptus resinifera , Taree, WWF #1941 (ANIC); 1 adult female: Eucalyptus sp., Hay, 1919, WWF #299 (BMNH); 1 adult female: Eucalyptus robusta , Sydney Harbour, 20 Dec., 1929, WWF (BMNH). Northern Territory: 5 adult females, 13 adult males: Eucalyptus camaldulensis var. obtusa , ca 120 km W of Alice Springs, Ormiston Gorge, 29 May, 1977, PJG (ANIC); 4 adult females: ex galls on leaves, Eucalyptus camaldulensis , Serpentine Gorge Nature Park, 27 May, 1992, PJG and P. S. Cranston (ANIC). Queensland: 1 adult female: ex gall, Eucalyptus resinifera , on road from Paluma to Hidden Valley, -19.02°; 146.12°, 30 Oct., 2003, LGC and M. D. Crisp, LGC00066 (ANIC); 4 adult females: Eucalyptus rostrata (now Eucalyptus camaldulensis ), Barakula, 13 Apr., 1939 (QDPI); 1 adult female: Eucalyptus rostrata (now Eucalyptus camaldulensis ), Barakula, Nov. 1939, No, 784 (QDPI); 5 adult females: Eucalyptus crebra , Clermont, Nov. 1939 (QDPI); 5 adult females: Eucalyptus melliodora or Eucalyptus rostrata (now Eucalyptus camaldulensis ), Emu Vale, 8 Feb., 1939, No. SC394 (QDPI); 5 adult females: on leaves, Eucalyptus rostrata (now Eucalyptus camaldulensis ), Emu Vale, 15 Mar., 1939 (QDPI); 3 adult females: Eucalyptus propinqua , Monto, 9 Nov. 1938, No. SC375 (QDPI); 3 adult females: Eucalyptus saligna , Pechey, 5 Mar., 1937, INSECOLL 0-067151, 0-067152 (QDPI); 2 adult females and ca 25 first-instar nymphs: Eucalyptus pilularis , Pechey, May 1938, No. SC326 (QDPI); 3 adult females: Eucalyptus tereticornis , Redland Bay, 9 Apr., 1939, No. 785 (QDPI); 1 adult female: Eucalyptus grandis , Tamborine, 20 Jan., 1954, INSECOLL 0-067167 (QDPI). Victoria: 1 adult female: ex gall on leaf, Eucalyptus camaldulensis , 27 km E of Shepparton, nr Midland Hwy, 8 Feb., 2004, PJG, LGC00099 (ANIC); 4 adult females: ex galls on leaves, Eucalyptus camaldulensis , Bundoora, La Trobe University, Wildlife Reserves off Ring Road, -37.72°; 145.05°, 14 Feb., 2005, PJG and NBH, NH43 (ANIC, NMV); 7 adult females: Eucalyptus mcintyrensis (=? Eucalyptus camaldulensis or a hybrid), Glenthomson, 14 Feb., 1964, HMB, Specimen Index No. 08/64 (ANIC); 1 adult female: ex leaf gall, Eucalyptus camaldulensis , Mildura, River Road near Lock 11, Murray River, -34.17°; 142.16°, 4 Feb,. 2005, NBH and PJG, NH75 (ANIC); 1 adult female: ex globose gall on leaf, Eucalyptus?camaldulensis , Shepparton, near Broken River, off Lincoln Drive, close to Goulburn Valley Hwy, -36.40°; 145.39°, 30 Jan., 2005, PJG, NH72 (ANIC); 1 adult female: ex globose leaf gall, Eucalyptus?microcarpa , Shepparton, near Goulburn River, off Tom Collins Drive, -36.39°; 145.39°, 29 Jan., 2005, PJG, NH71 (ANIC). Western Australia: 8 adult: ex galls on leaves, Eucalyptus camaldulensis , Winjana Gorge Nat. Park, bank of Lennard River, -17.42°; 124.95°, 29 Apr., 1992, PJG (ANIC). PAPUA NEW GUINEA: 8 adult females, 20 first-instar nymphs: ex galls on leaves, Eucalyptus alba , Central Province, Sogeri, -9.43°; 147.58°, 10 Apr., 1980, H. Roberts (ANIC, BMNH).

Comments.

Adult females of Opisthoscelis subrotunda most closely resemble those of Opisthoscelis beardsleyi [see comments under Opisthoscelis beardsleyi ]. Specimens of Opisthoscelis subrotunda have been collected from six Australian states or territories as well as Papua New Guinea. This is the only species of Opisthoscelis or Tanyscelis to have been collected outside of Australia. Opisthoscelis subrotunda also appears to have a much broader host range than is typical for species of Opisthoscelis and Tanyscelis . Specimens have been collected from Corymbia in addition to hosts in the Eucalyptus sections Adnataria , Exsertaria , Latoangulatae , and Similares (all in subgenus Symphyomytrus ). A common host of this species is the river red gum, Eucalyptus camaldulensis , which has the widest natural distribution of any eucalypt species and seven subspecies ( Chippendale 1988; McDonald et al. 2009). The length of the dorsal setae, and the size of the cribriform plates of the adult females of Opisthoscelis subrotunda vary, but in general, the morphology is remarkably homogeneous across samples. Molecular data from collections of fresh material from across the geographic range of the taxon would be required to determine if cryptic species are present.