Larrisson orbitalis Pulawski, 2012

Pulawski, Wojciech J., 2012, A review of the genus Larrisson Menke, 1967, and description of the new genus Larrissa (Hymenoptera, Crabronidae), Journal of Hymenoptera Research 25, pp. 35-82 : 49-50

Larrisson orbitalis Pulawski sp. n. Figs 6 9

Name-derivation.

Orbitalis is a Latin masculine and feminine adjective derived from orbita; with reference to the conspicuously convex inner eye orbits of this species.

Recognition.

The female of orbitalis has a red gastral base and a densely punctate mesothoracic venter, with the integument totally concealed by vestiture. Three other species, armatus, quintus and variegatus, share these characters, but orbitalis differs from quintus in lacking dense, small punctures on the outer surface of the hindtibia (between the spines); unlike armatus, the unsculptured medioventral area of the clypeus does not extend to clypeal midlength; and unlike variegatus, the inner eye margins of orbitalis are markedly bowed toward the frons midline ( Fig. 9a ), rather than nearly parallel, and the first recurrent vein is received by the first submarginal cell, rather than the second.

The male of orbitalis shares with quintus the posterior mandibular margin that is angulate between base and notch ( Fig. 9c ). Unlike that species, the legs of orbitalis are unspecialized: the forefemoral venter is not expanded subbasally and not concave anterobasally, the inner margin of the forebasitarsus is straight, the foretarsomeres II-IV are not expanded on the inner side, and the hindbasitarsus is not convex on outer margin. The emarginate apically sternum VIII, with a glabrous basal platform, is a subsidiary recognition feature of the male orbitalis.

Description.

Width of face across clypeus and vertex = 60:52, least interocular distance 50 in female, in male, respectively, 60:58 and 40. Orbital fovea ill defined, about as wide as half ocellocular distance in female, less than that in male. Inner eye margin markedly bowed out toward frons midline ( Figs 9a, b ). Clypeal lobe only slightly prominent, its free margin arcuate, rounded laterally. Scapal basin punctate along margins in female, impunctate in male. Length of scape (excluding radicle) 2.5 × width, length equal to flagellomeres I-IV + half V combined in female, to flagellomeres I-III + half IV combined in male. Scutal punctures less than one diameter apart. Mesopleuron with ill-defined tubercle at top of precoxal declivity in female, with obtuse, transverse carina in front of midcoxa in male; mesothoracic venter densely punctate throughout (punctures less than one diameter apart). Metanotum with low median carina in female, with well-defined median tooth in male. Propodeum with tubercle behind spiracle (tubercle ill defined in female); side conspicuously ridged; posterior surface ridged both mesodorsally and mesoventrally in female, with irregular sculpture mesodorsally and not ridged medioventrally in male. Outer surface of hindtibia impunctate and asetose between spines in dorsal half. Tergum I concave basally.

Setae all silvery, appressed on head, thorax, propodeum, and legs, nearly completely concealing integument on clypeus (except glabrous ventral portion of median lobe), on frons lateroventrally (on scapal basin markedly shorter than on remaining frons and not concealing integument in female, absent in male), on mesopleuron, and in female on mesothoracic venter (not so in male); in female setae of pygidial plate light brown, not concealing integument. Hindfemoral venter asetose, inner (= posterior) face setose except asetose along dorsal margin in male.

Head, thorax, and propodeum black except the following are pale yellow: scape (only ventrally in male), mandible basally (black apically), and pronotal lobe; flagellum black dorsally, brown ventrally in female, brown dorsally and yellow ventrally in male (dark brown basally, light brown apically, flagellomeres X-XIII all light brown). Color of legs and gaster: see below.

Female. Forebasitarsus with four rake spines, apical spine of foretarsomere III about equal to 0.7 × apical basitarsal width. Pygidial plate with punctures that are more than one diameter basally, less than one diameter apart apically. Length 7.4 mm. Forefemur black basally, yellow apically, mid- and hindfemora reddish brown, yellow apically; foretibia reddish brown on inner surface, yellow on outer surface; midtibia reddish brown except yellow apically; hindtibia reddish brown; forebasitarsus yellowish brown, foretarsomeres II-V brown; mid- and hindtarsi reddish brown. Gastral terga I and VI reddish brown, tergum II reddish brown with black basomedian spot, terga III and V black except reddish brown apically, tergum IV black

Male. Posterior mandibular margin angulate between base and notch, concave adjacent to notch ( Fig. 9c ). Flagellum cylindrical; dorsal length of flagellomere I 1.4 × apical width. Tergum VII rounded apically. Sternum II with transverse, glabrous swelling behind midlength (swelling higher laterally than mesally). Length 6.3 mm. Fore- and midfemora black basally and dorsally (except at apex), pale yellow ventrally (except near base) and apically; hindfemur black except pale yellow near apex; tibiae and tarsi pale yellow. Gaster black except tergum I and large median part of tergum II reddish brown and except apical depression conspicuously yellowish (inconspicuously so on tergum I).

Geographic distribution

( Fig. 6 ). Known from two localities in western New South Wales.

Specimens examined.

Holotype: ♀, AUSTRALIA: New South Wales: Springs Creek 68 km SW Wilcannia, 29 Nov 1981, J.C. Cardale and I.D. Naumann (ANIC). Paratype: New South Wales: Kinchega National Park at 32°22.8'S, 142°23.6'E, 30 Dec 2009, V. Ahrens and W.J. Pulawski (1 ♂, CAS).

Figures

Figure 6. Collecting localities of Larrisson carinatus, latifrons, niger, and orbitalis.

Figure 9. Larrisson orbitalis: a female head in frontal view b male head in frontal view c male mandible in lateral view.