Sphex sericeus (Fabricius, 1804)

Doerfel, Thorleif H. & Ohl, Michael, 2015, A revision of the Australian digger wasps in the genus Sphex (Hymenoptera, Sphecidae), ZooKeys 521, pp. 1-104 : 22-24

Taxon classification Animalia Hymenoptera Sphecidae

Sphex sericeus (Fabricius, 1804)

Sphex aurulentus Fabricius, 1793: 201, sex not indicated, junior primary homonym of Sphex aurulentus Fabricius, 1787 (now in Liris ). Holotype or syntypes: India: Tranquebar (depository unknown: van der Vecht 1961: 30). Not examined.

Pepsis sericeus Fabricius, 1804: 211, sex not indicated (as sericea , incorrect original termination). Lectotype: ♀, "in maris pacifici Insulis" (ZMUC), designated by van der Vecht 1961: 30. Not examined.

Material examined.

AUSTRALIA:[state unknown]: [no specific locality], 1♂ (BMNH); NT: Port Darwin, 5♀, 6♂ (BMNH); QLD: [no specific locality], 1♂ (ANIC); "North Queensland", 1♀ (BMNH); Allingham near Mackay, 1♂, 25.10.1984, N. W. Rodd (AMS); Archer Point, 10 km S of Cooktown, 1♂, 05.09.1983, N. W. Rodd (AMS); Barron Rivers, 1♂ (ANIC); Biloela, 1♂, 08.12.1926, E. Ballard (BMNH); Blackdown Tableland Expedition Range, 1♀, 08.01.1976, G. Daniels (AMS); Cairns, 2♂, 1919, Jarvis (ANIC); Cape Ferguson, Townsville, 1♀, 3♂, 21.-22.03.1978, N. Duke (ANIC); Cape York, 1♀, 02.06.1985, N. W. Rodd (AMS), 1♀, 3♂, 02.08.1986, N. W. Rodd (AMS), 2♂, 28.05.1991, N. W. Rodd (AMS), 1 ♀, 31.05.1991, N. W. Rodd (AMS), 1♂, May 1902 (BMNH), 1♂ (BMNH); Cooktown, 1♂, 18.07.1982, N. W. Rodd (AMS); Duaringa, 1♂, 26.12.1946, C. W. Smith (AMS); Ellis Beach N of Cairns, 1♀, 12.05.1967, D. H. Colless (ANIC); Endeavour River, Cooktown, 1♂, 05.10.1922, F. P. Spry (ANIC); Gayndah, 2♀ (AMS); 5 km SEbyS of Helenvale, 15°44'S, 145°15'E, 1♀, 25.08.1992, J. Cardale & P. Zborowski (ANIC); Inkerman, 1♂, W. Stalker (BMNH); Mackay, 1♂, May 1893 (BMNH), 1♀ (BMNH); Mitchell River Settlement, 1♀, 01.04.1969, A. L. Dyce (ANIC); 4 miles NE of Mount Lamond, 1♀, 02.12.1971, D. K. McAlpine & G. A. Holloway (AMS), Quarantine Bay near Cooktown, 1♂, 13.06.1985, N. W. Rodd (AMS); Redlynch, 1♂, Dec 38, H. F. Sternitzky (BMNH); Thursday Island, 1♂, 14.01.1939 (BMNH); Townsville, 1♂, 03.04.1902, F. P. Dodd (BMNH); Westwood, 1♂, 09.12.1923, A. N. Burns (ANIC); WA: Baudin Island, 1♀ (BMNH), Roeburne, 1♀ (BMNH). INDONESIA:Papua: Yerelua, 1♂, 26.07.1998, Balke & Konyorah (NHMW). PAPUA NEW GUINEA:Western Province: Daru Island, 1♀, 05.05.-18.05.1921, E. O. Pockley (AMS).

Diagnosis.

Sphex sericeus is unique among its Australian congeners in having three to four broad, continuous transverse ridges on the propodeal enclosure which are even visible through the pubescence. Female specimens of Sphex rugifer , Sphex darwiniensis and Sphex imporcatus possess vaguely similar structures, but those are much finer. Sphex rugifer also has approximately 20 ridges on the propodeal enclosure, while those of Sphex darwiniensis and Sphex imporcatus are discontinuous in the center.

Description.

Clypeus with medial glabrous stripe. Pubescence on scutum slightly denser laterally. Scutellum slightly convex, with shallow medial impression near posterior margin. Tubercles on metanotum distinct. Propodeal enclosure with three to four broad, continuous transverse ridges; propodeal pubescence not concealing sculpture. Tomentum moderately dense on metasomal terga I and II.

Female: Body length 20.2-25.7 mm. Body black, but the following are orange: basal half of mandible, clypeus, scape, pedicel, parts of flagellomere I, scutellum, metanotum, petiole, metasomal segment I, anterior two thirds of metasomal segment II, legs excluding claw teeth and distal half of claw. Wing membrane with yellow tinge and markedly fuscous band at apex. Wing veins orange, dark near apex. Forebasitarsal rake with nine long spines. Free clypeal margin conspicuously notched medially, bulging above. Appressed pubescence and erect setae on clypeus and frons golden. Distance between hind- ocelli 0.7 × their shortest distance to compound eyes. Pubescence on mesosoma golden. Length of petiole 1.4 × length of flagellomere II.

Male: Body length 16.8-23.6 mm. Wing membrane largely hyaline, with slight yellow tinge around costal cell. Forewing with faint fuscous band at apex. Wing veins dark brown to orange. Free clypeal margin concave towards center. Appressed pubescence and erect setae on clypeus and frons silvery-white. Distance between hind- ocelli nearly equal to their shortest distance to compound eyes. Pubescence on mesosoma silvery. Length of petiole 1.6 ×–1.7× length of flagellomere II. Metasomal terga V and VI with few silvery bristles. Metasomal sterna II–VIII largely glabrous. Metasomal sternum VIII entire, its lateral margin sometimes slightly concave.

Variation.

Males of this species markedly vary in color, though most Australian specimens belong to either one of two forms: the first form has the following parts bright red: anterior side of midfemur, entire hindfemur, petiole, metasomal segments I and II (Fig. 14B), while the body of the second form is entirely black (Fig. 14C). The color of the females seems to be more or less uniform among the collecting localities.

Notes on type material.

The types of Sphex sericeus and its synonyms were not examined, because the character combination in the redescription by Kohl (1890) (broad transverse ridges on propodeal enclosure, bituberculate metanotum) is sufficient to unambiguously identify this species. Van der Vecht (1961) noted that the lectotype of this species agrees with the species current (i.e., Kohl’s) interpretation.