Metallesthes metallescens ( White, 1859 )

Moeseneder, Christian H., Hutchinson, Paul M. & Lambkin, Christine L., 2014, Revision of the genus Metallesthes Kraatz and description of Metallesthes anneliesae, a new species of Cetoniinae (Coleoptera: Scarabaeidae) from Queensland and New South Wales, Australia, Zootaxa 3881 (4), pp. 301-327 : 312-316

Metallesthes metallescens ( White, 1859)

( Figs. 3 , 6 B, 6D, 8C, 7A–E, 7G, 7I, 7L–M, 7P)

Diaphonia metallescens White, 1859: 119 .

Metallesthes metallescens . — Kraatz 1880: 203; Masters 1886: 85; Schoch 1895: 57; Lea 1914: 188; Schenkling 1921: 192; Matthews 1984: 10; Cassis & Weir 1992: 446; Allard 1995: 139; Calder 2002; Reid & Bulbert 2002; Golding 2009: 36. 166; Krajcik 2012: 159.

Schizorhina metallescens . — Tepper 1887: 14.

Material examined (848 specimens). Holotype, male ( Fig. 3 ): AUSTRALIA: Swan River [Perth, W.A.], no date, 5175 [ NHML]. Condition: specimen complete and undamaged.

Other material (392 males and 455 females) AUSTRALIA. WESTERN AUSTRALIA: 1 m. / 1 f., 15 km W of Balladonia, 24.i.1997 [ PMH]; 2 m., Bejoording, 21.i.1937 [ WAM]; 3 m., E of Boondi Rock, 10.ii.2011 [ MIC]; 2 m., Boorabbin N.P., 16.i.2002 [ WAM]; 1 m. / 6 f., Boorabin, 25.i.1990 [AM]; 3 m. / 2 f., 1 km W of Boorabbin Rock, 9.i.1985 [ WAM]; 3 m. / 4 f., Borden, 28.i.1961 [ DAFWA / WAM]; 3 m. / 1 f., Bullabulling, i.1939 [ NMV]; 1 f., 37 km N of Bullfinch, 30.i.2000 [ PMH]; 1 f., Bulong, 22.i.1968 [ WAM]; 1 m. / 2 f., Burngup [ WAM]; 1 m., Carrabin, 27.i.1971 [ DAFWA]; 1 f., Cheyne Beach [assumed Cheynes Beach], i.1970 [ WAM]; 4 m. / 4 f., Coyrecup, 12.ii.1967 [AM]; 7 m. / 2 f., Cranbrook, 2.ii.1954 / 4.ii.1954 [ WAM]; 11 m. / 9 f., Cunderdin, no date/ ii.1914 [AM/ QDPC /QM/ SAM]; 100 m. / 169 f., Dedari, ii.1914/ 11-21.i.1936 / 23-25.i.1962 /21-23.i.1966/ 23.i.1968 /28-29.i.1968/ 29.i.1970 / 28.i.1971 / 20.i.1982 / 16.ii.1982 / 25.i.1990 / 16.i.2002 [ AH /AM/ ANIC / DAFWA / NHML / SAM / WAM]; 1 f., 52 km W of Dedari, 24.i.1987 [ WAM]; 1 m. / 1 f., Doodlakine [ WAM]; 1 m., Eradu [ NMV]; 2 m., Esperance Bay, 1894 [ ANIC]; 5 m. / 5 f., Fitzgerald River N.P., 8.ii.1982 / 8-12.ii.1984 [ AH / WAM]; 1 m., 2 km NNE of Fraser Range H.S., 22.i.1975 [ ANIC]; 4 m. / 2 f., 10 mi N of Hopetoun, 28.ii.1976 [ WAM]; 3 m. / 1 f., Highbury, 6.ii.1965 [ WAM]; 1 f., Hopetoun, 1.iii.1971 [ DAFWA]; 1 m. / 1 f., 3 km N of Hopetoun, 9.ii.2003 [ PMH]; 1 f., Hyden, ii.1985 [ AH]; 2 m. / 2 f., East Hyden, 23.i.1970 / 28.i.1970 / 2.ii.1983 [ AH, AM, WAM]; 1 m. / 1 f., 25 km S of Hyden, 25.ii.1978 [ WAM]; 7 m. / 9 f., 54 km E of Hyden, 28.i.1970 [AM]; 1 m. / 1 f., 90 km E of Hyden, 2.ii.1990 / 12.ii.1990 [ MIC]; 2 m., Jerramungup, 24.ii.1979 [ AH]; 1 m. / 3 f., Kalannie, 20.i.1976 [ WAM]; 2 m. / 1 f., Kalbarri, 10.i.1963 [ DAFWA]; 1 m., Kalgoorlie [ ANIC]; 1 f., Kellerberrin, 3.ii.1907 [ DAFWA]; 1 f., Kodin Is., 1967 [ WAM]; 2 m., Kuminin [assumed Kumminin] [AM, SAM]; 2 m. / 3 f., Kundip, no date/ 5.ii.1967 [ AH / WAM]; 5 m. / 3 f., Tundip [assumed Kundip], i.1952 [ NHML]; 2 f., Lake Cowan, 9.ii.1999, dead on lake [ DAFWA]; 14 m. / 6 f., Lake Cronin, 19.ii.1970 / 29.i.1971 / 16.ii.1974 / 19.ii.1977 [ DAFWA]; 5 m. / 4 f., Lake Grace, 16.ii.1971 / 2.ii.1976 [ AH / DAFWA / QM]; 1 m. / 1 f., Lake Hurlstone nr. Lake King, 3.ii.1992 [ PMH]; 9 m. / 5 f., Lake King, 26.i.1968 / 12.ii.1971 / 26.i.1978 / 14.ii.2011, dead on shoreline [ AH /AM/ MIC / WAM]; 2 f., Lake King town, 15.ii.2009 [ PMH]; 3 f., 16 km W of Lake King, 24.ii.1999 [ PMH]; 1 m. / 1 f., 66 km N of Lake King, 26.i.1997 [ PMH]; 1 m., Lake Lefroy, ii/ iii.1994 [ SAM]; 1 f., Lake Seabrook, 4.ii.2006, dead on lake edge [ PMH]; 1 m. / 1 f., Latham, 31.i.1971 [ DAFWA]; 3 m. / 5 f., Lefroy River nr. Nyabing, 15.ii.1967 [AM]; 1 m. / 5 f., Marloo Stn. Wurarga, 1931-1941 [ ANIC]; 1 m., Merredin, 25.i.1973 [QM]; 2 f., Merriden [assumed Merredin] [ DAFWA]; 1 f., Moorine Rock, 21.i.1978 [ WAM]; 1 m. / 2 f., Mt. Jackson [ WAM]; 3 m. / 4 f., Mt. Gibson Stn., 12.i.2000 / 16.i.2000 / 7.ii.2000 / 9.i.2002 / 14.i.2004, 1 specimen at light [ WAM]; 3 m. / 16 f., Mt. Ragged, 17-18.ii.1970 [ WAM]; 1 m. / 8 f., Mullewa [AM/ NHML / SAM / WAM]; 1 f., Murchison [ DAFWA]; 1 m. / 1 f., Narrogin, no date/February [ DAFWA]; 1 m. / 3 f., Newman Rock, 26.ii.1975 [ SAM]; 22 m. / 14 f., 40 mi. E of Norseman, 5.iii.1970 [ WAM]; 6 m., 161 km E of Norseman, 24.i.1990 [AM]; 1 f., Norseman-Coolgardie Road, 16.ii.1982 [ SAM]; 1 m., Northam [AM]; 1 f., Northampton, 1.i.1972 [ DAFWA]; 1 m., Nugadong N.R., 7.ii.2011 [ MIC]; 1 f., Nulla Nulla [ WAM]; 14 m. / 24 f., Nyabing, ii.1946/ 7.iii.1966 / 12-16.ii.1967 / 19.i.1991 [AM/ NHML]; 1 m., Lyabring [assumed Nyabing] [AM]; 12 m. / 12 f., Ongerup, iii.1952/ 3.iii.1952 [ WAM]; 1 m., 8 mi E of Ongerup, 11.i.1973 [ SAM]; 1 f., 17 km S of Ongerup, 10.iii.1971 [ DAFWA]; 4 f., Perth [QM]; 1 m., Piawanning, 22.i.1950 [ WAM]; 1 f., Pingaring, 19.ii.1978 [ WAM]; 1 m., Pingelly [QM]; 3 m. / 1 f., Pinjarrega Lake N.R., 19.i.1996 [ WAM]; 3 m. / 2 f., Ravensthorpe, 3.ii.1977, at light [ ANIC]; 14 m. / 12 f., Moir Road, 8 km S of Ravensthorpe, 13.ii.2011 / 15.ii.2011 [ MIC]; 1 f., S.E. Kondinin [ WAM]; 1 m., Salmon Gums [ WAM]; 1 m., Salt River [AM]; 1 f., Salt River Road, Sterling Ranges, 21.ii.2008 [ PMH]; 7 m., Southern Cross, 24.i.1958 [ WAM]; 1 m. / 1 f., SW of McDermid Rock, 10.ii.1981 [ WAM]; 3 m. / 1 f., Swan River [ DAFWA / NHML]; 27 m. / 16 f., Tarin Rock, 11-12.ii.2008 [ MIC / PMH]; 3 m., Wanneroo [ WAM]; 1 m., Watermans Bay nr. Perth, 10.i.1965 [ NHML]; 2 m. / 1 f., Widgiemooltha, 24.i.1968 [ WAM]; 1 f., Wongan Hills, 1917 [ WAM]; 5 m. / 9 f., Woorgabup Hill nr. Nyabing, 21.ii.1967 / 21.ii.1976 [AM]; 1 m., 10 km S of Wubin, 30.i.1996 [ PMH]; 1 f., 30 km NNE of Wubin, 19.i.1996 [ PMH]; 1 f., 60 km N of Wubin, 22.i.2010 [ MIC]; 2 f., Wurarga, i.1939 [ ANIC]; 5 m. / 5 f., Yellowdine, 21.i.1962 / 16.i.1980 [AM/ WAM]; 6 m. / 4 f., Lake Cronin Road, Yellowdine, 30.i.1990 [AM]; 1 m., 5.5 km S of Yellowdine, 30.i.2001 [ PMH]; 3 m., 20 km S of Yellowdine, 29.i.1999 [ DAFWA / WAM]; 1 f., 50 km E of crossroads Southern Cross, Hyden, Norseman Road, 19.i.1991 [AM]; 1 f., Zanthus, i.1928 [ ANIC]; 1 f., i.1948 [ ANIC]; 1 m., 26.iii.91 [ SAM]; 1 m. / 7 f., [ DAFWA / NHML / NMV /QM/ WAM]. SOUTH AUSTRALIA: 2 m. [AM]. NEW SOUTH WALES: 1 m. / 1 f. [ WAM]. QUEENSLAND: 1 f., Archer River, 30.xii.1983 [AIF]. WITHOUT INFORMATION: 7 m. / 10 f. [ AH /AM/ NHML / NMV /QM/ SAM].

Diagnosis. Males with asymmetric proclaws ( Fig. 7 I), mesotibia and metatibia dorsal surface with row of peglike cilia ( Fig. 7 E), phallobase with sclerotised ventral surface, saddle-shaped area ( Figs 6 B, 7G). Females with setose pygidium and apex of elytra ( Fig. 7 M). Coarse pronotal and elytral punctation in both sexes. Other characters, developed to a greater or lesser degree: metallic reflections, usually green, on elytra and legs; apical denticle on protibia wider in female; mesometasternal process ventrally divergent from body. Generally, M. metallescens with metallic shiny dark purple and bronze base colour, more or less green. Male M. metallescens often lighter, shinier, bronze/green. Female M. metallescens usually less shiny, dark purple. Differences compared to M. unicolor : males with asymmetric proclaws; mesotibia and metatibia dorsal surface with row of peg-like cilia. Females with pygidium and apex of elytra setose. Similarities with M. unicolor: Size , clypeal apex elongate and notched ( Fig. 7 P), coarse pronotal and elytral punctation, laterally expanded mesometasternal process. Some female M. metallescens and M. unicolor can be very similar. Differences compared to M. anneliesae: larger ; clypeus more elongate, quadrate in M. anneliesae ; posthumeral emargination not clearly and broadly exposing abdominal sternites laterally and apically ( Fig. 7 L); less pronounced costae; pygidium setose, glabrous in M. anneliesae . Metallesthes anneliesae with black lacquer sheen base.

Redescription. Holotype. Male ( Figs 3 , 6 B). Length 20.0 mm, width 11.4 mm. Dark violet, all surfaces with brassy metallic reflections. Head. Clypeus longer than wide; clypeolateral ridge apically narrowed, raised steeply basally; linear in apical half, lateral declivity distinct in dorsal view, widest at midlength; apical lobes broadly rounded with a distinct, deep anteromedian emargination. Antenna with ten antennomeres. Club with 3 antennomeres, short, ovoid, approximately same length as antennomeres 2–7. Scape with posterior fringe and apical cincta of long, pale setae; antennomeres 2–7 with several pale setae; clypeus and frons coarsely punctate often coalesced and bearing long fine setae proximally. Mentum clothed with very long, golden setae. Thorax. Pronotum transverse trapezoidal, base trisinuate, baso-lateral angle acute, not produced, lateral margin slightly concave-linear in basal half becoming arcuate to apex; lateral margin sharply raised, narrow on lateral portions of apical margin, obsolete across middle and basal margin. Surface evenly coarsely punctate, often coalesced, each puncture bearing a long pale seta, midline impunctate. Scutellum slightly elongate, apex acute, bearing coarse punctures except in impunctate apical midline, each with a long pale seta. Elytron; posthumeral emargination shallow sinuate, exposing metacoxa and small part of each abdominal sternite; bicostate (not counting sutural costa), indistinct. Sutural costa indistinct without distinct margins, terminating pre-apically of scutellum, raised in apical 3/4, tapering apically, non-spinose, bearing macropunctures often coalesced. First costa indistinct, barely raised; second costa indistinct, slightly raised; both traversing from between humeral umbone and scutellum to apical umbone. Costal intervals irregularly, coarsely punctate, often coalesced becoming finer on humeral umbone, with distal declivity and lateral declivity becoming rugulose; all punctures bearing long, pale setae; epipleural pilosity continuous to apex. Legs. Profemur dorsoventrally flat; ventral surface bearing very long, pale setae.

Protibia tridentate; denticles narrow, acute with medial and basal denticles slightly closer. Apical spur almost reaching apex of protarsomere 2; dorsal surface with several rows of punctures, each bearing pale setae. Ventral surface with distinctly raised inferior ridge, sharp apically, continuous with anterior margin of apical denticle and bearing short, pale setae along basal half; region adjacent to internal margin bearing row of pale setae; external region with rows of coalesced macropunctures bearing short, pale setae. Protarsomeres short, stout; tarsomeres1–4 equal length, tarsomere 5 longer, wider with blunt, parallel-sided ventrodistal process; proximal edge broadly rounded. Claws distinctly asymmetric, external claw approximately 3/4 length of internal claw, abbreviated in apical half. Mesofemur subparallel, dorsoventrally flat; ventral surface rugulose bearing long, pale setae; external margin bearing very long, pale setae. Mesotibia internal margin abruptly slightly divergent from midlength; external margin divergent to basal third with 1 denticle and serrated edge, narrowing to apical third, then slightly divergent to apex; ventral surface rugulose except along internal margin, appearing serrate in lateral view, with sparse, short pale setae medially; dorsal surface along external margin bearing several rows of long pale setae, adjacent to internal margin bearing 2 rows of very short, peg-like cilia; apex with 2 spines of equal length, interval deeply incurved; 2 apical spurs, fine, tapering, acute, closely set, surpassing tibial apex, dorsal spur longer; ventral surface with several rows of punctures particularly along base of external margin becoming finer apically and bearing few short, pale setae in basal half; dorsal surface bearing several rows of long, pale setae; internal margin bearing 2 rows of setae, becoming shorter apically. Mesotarsi not elongate; tarsomeres 1–4 equal length; tarsomere 5 longest with 2 stout bristles on apex of ventral surface of tarsomeres 2–5; tarsomere 5 with blunt, parallel-sided ventrodistal process, proximal edge broadly rounded, 3 increasingly large bristles basally to process. Claws asymmetric with internal claw approximately 4/5 length of external claw. Metafemur divergent apically; posterior margin slightly curved; anterior margin strongly convex, dorsoventrally flat; ventral surface with punctures, becoming rugulose near internal margin. Metatibia somewhat compressed, internal margin sinuate, convex basally and concave apically; external margin linear with indistinct medial and premedial denticles; apex obliquely linear; 2 apical spurs fine, acute, closely set, distinctly surpassing tibial apex; dorsal spur approximately twice length of ventral spur, attaining apex of tarsomere 2; ventral spur curved. Metatarsi slightly elongate; tarsomeres 2–4 equal length; tarsomere 1 shorter, tarsomere 5 longest; several long bristles on apicoventral surface of tarsomeres 2–5; tarsomere 5 with blunt, parallel-sided ventrodistal process, proximal edge broadly rounded, several bristles basally to process. Claws almost symmetric, internal claw slightly shorter. Mesometasternum base broad, projection moderately laterally divergent; apex produced medially; mesometasternal process reaching posterior of procoxae, in lateral view divergent and apical angulate prior to apical declivity; surface impunctate and glabrous, declivity bearing moderately dense long pale setae. Metasternum densely rugulose and moderately clothed in very long, pale setae; micropunctate and glabrous medially. Mesometasternal process ( Fig. 6 D), metasternum and abdominal sternites jointly forming concave ventral area. Abdomen. Abdominal sternites 2–6 with broad, shallow median impression; surface micropuncatate, glabrous; laterally with dense punctures becoming denser laterally and with setae becoming denser and longer laterally. Propygidium clothed in long, pale setae. Pygidium transverse, length:width ratio 1:1.8, rugulose around 2 close centres; entirely clothed in long, pale setae. Genitalia ( Fig. 6 B). Not dissected on type, therefore redescription based on NHML specimen from Kundip, W.A., I 1952, “comp. with type ” remark by M.E. Bacchus. Parameres with ratio to phallobase approximately 1:2.5, wide and parallel at base due to lateral projection, concave arcuate to preapex then attenuate to apex; small area in apical corners less sclerotised, lighter; dorsal cleft narrow, parallel in basal 2/3 then attenuate to apex; medial third of ventral surface of phallobase sclerotised, saddle form; phallobase dorsal surface with medial longitudinal impression in apical 2/3. Female. Based on specimen 60998-043, Ravensthorpe, W.A., 13.ii.2011 [MIC]. Length 21.5 mm, width 12.1 mm. Differs from the holotype in the following characters. Broader thorax; pronotum, basolateral angles forming right angles. Legs: All claws symmetric. Protibial denticles, especially foredenticle, longer and broader. Mesotibial denticles larger, broader, peg-like cilia on dorsal surface absent. Metatibia not compressed, external margin bearing 1or 2 distinct denticles, apex bispinose with interval broad and sinuate; 2 apical spurs broad, parallel with round apices; ventral surface rugulose along external margin, medially micropunctate; peg-like cilia absent. Tarsomeres 1–4 equal length. Abdomen; sternite 6 broader and setose across middle in apical half. Sternites convex. Pygidium narrowed apically forming v-shape. Setae shorter.

Variation in specimens. Males. Length 18.5–20.5 mm, width 9.5–10.5 mm. Females. Length 15.0– 22.5 mm, width: 8.5–13.0 mm.

Ecology. Metallesthes metallescens adults are found feeding on the flowers of a variety of bushes and trees ( Figures 7 A–C, Table 5). All specimens observed or collected by the authors (10% of material examined) were on flowers. In 17 years of recorded observations in Western Australia, PMH never saw M. metallescens in flight, although adults fly readily when netted. This may indicate that adults arrive on flowers early in the day.

Lea (1924) wrote that adult M. metallescens were observed on flowers of Xanthorrhoea (Xanthorrhoeaceae) at Barossa, S.A. in December. While the species that he observed is probably not M. metallescens due to the location, he may have been referring to M. unicolor , especially since Lea considered M. unicolor to be a variety of M. metallescens . It is also possible that this was an observation of Micropoecila cincta because that species emerges earlier and is known to breed in decaying stems and trunks of Xanthorrhoea . A series of five Micropoecila cincta Kraatz, 1880 specimens in the collection of the AM (identified by CHM) are almost black in colour and that might account for confusion between the two species if the black form was observed at Barossa.

Three males and two females in the ANIC collection carry labels that state they were collected at light at Ravensthorpe, W.A., which is remarkable since Australian cetoniines have rarely been collected at light. PMH has encountered only one cetoniine species (not Metallesthes ) at light in 30 years of collecting in Western Australia. A male M. metallescens specimen in ANIC bears a label indicating it was prey of a male Phellus piliferus Dakin & Fordham, 1922 ( Diptera : Asilidae ), a rarely collected robber fly of 45 mm in body length ( Dakin & Fordham, 1922).

At Comet Vale (28.2 km S of Menzies, W.A.) PMH and CHM found remnants of adult M. metallescens in the root stock of a mallee tuber (multi-stem Eucalyptus [ Myrtaceae ]) ( Fig. 8 D) along with remnants of adults and living larvae of Dilochrosis walteri Lea, 1914 and Chlorobapta goerlingi Schürhoff, 1942 . Larvae of the latter species were reared to adults. Approximately 28 km NNE of Bullfinch, W.A. we found remnants of an adult M. metallescens in the base of a large, single-stemmed eucalypt, which was exposed and decaying. It is possible that M. metallescens females enter and burrow into rotting eucalypts and lay eggs in the root stock that provides developing larvae with sufficient food.

Figures

FIGURE 3. Metallesthes metallescens male holotype. A—Hand-coloured drawing of type from White (1859) (plate LVIII, fig. 8). B, C, D, E—Holotype male. Images by Helena Maratheftis (MNHL).

FIGURE 6. Metallesthes parameres and mesometasternal process in several taxa. Metallesthes parameres. A – M. anneliesae, B – M. metallescens, C – M. unicolor. Lateral (left) and dorsal (right) views. Arrow indicates sclerotised area on phallobase of M. metallescens. Mesometasternal process. D – M. metallescens, Aphanesthes trapezifera and A. pullata, E – M. anneliesae and A. pullata, F – Tapinoschema digglesii, G – Diaphonia xanthopyga and A. succinea, H – Bisallardiana decorticata, I – Pseudoclithria maura and P. rugosa, J – P. ruficornis, K – Micropoecila cincta. Abbreviations: mc / f – mesocoxa and mesofemur, pc / f – procoxa and profemur.

FIGURE 7. Metallesthes diagnostic and sexual characters. A, B—sternital impression (A—males of all species; B—females of all species); C, D—metatibia apex (C—males of all species; D—females of all species); E, F—metatibia row of cilia (E—males of M. metallescens; F—males of M. anneliesae and M. unicolor); G, H—sclerotised patch on phallobase (G—males of M. metallescens; H—males of M. anneliesae and M. unicolor); I, J—proclaw symmetry (I—males of M. metallescens; J—both sexes of M. anneliesae and M. unicolor); K, L—dorsal visibility of sternites (K—both sexes of M. anneliesae; L—both sexes of M. metallescens and M. unicolor); M, N—apical pilosity (M—females of M. metallescens; N—females of M. unicolor); O, P—head shape (O—both sexes of M. anneliesae; P—both sexes of M. metallescens and M. unicolor). Grey shading and arrows emphasise diagnostic characters.

FIGURE 8. Metallesthes habitat. A, B, C— M. metallescens feeding on flowers of host plant (A, B: Comet Vale, W. A., 5 January 2014. C: Woolgangie, W. A., 3 January 2014). D— M. metallescens larval habitat. Arrow indicates location of excavation and position of adult M. metallescens remnants. (Comet Vale, W. A., 11 February 2011). E—Collecting Metallesthes anneliesae on Angophora costata (Dunmore SF, Qld, January 2011).