Palaeoscydmaenus australiensis Franz

Jałoszyński, Paweł, 2012, Systematic position of Australian genus Palaeoscydmaenus Franz (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 3501, pp. 63-73 : 69

Palaeoscydmaenus australiensis Franz

( Figs. 10–19 )

Palaeoscydmaenus australiensis Franz, 1975: 273 , Figs. 248–249.

Type material studied. Holotype (labels as in Fig. 12 ): Australia: 3, Port Lincoln, S.A. Lea leg. ( SAM).

Revised diagnosis. This is the only species of Palaeoscydmaenus and can be identified on the basis of generic characters and the aedeagus ( Figs. 18–19 ).

Redescription. BL 1.33 mm. Body of male ( Fig. 10 ) elongate, slender and strongly convex; cuticle glossy; pigmentation yellowish brown; vestiture pale yellow.

Head ( Figs. 13–14 ) broadest at small, finely faceted and moderately convex eyes, HL 0.23 mm, HW 0.20 mm; tempora in dorsal view arcuate, in lateral view distinctly shorter than eyes; vertex evenly but weakly convex; frons between eyes flattened and in front of eyes rapidly sloping anterad; supraantennal tubercles barely marked. Punctures and setae of head dorsum unremarkable, fine and sparse. Antennae long and slender, AnL 0.75 mm, as in Fig. 15 .

Pronotum ( Fig. 10 ) in dorsal view elongate subtrapezoidal, broadest near anterior third, PL 0.35 mm, PW 0.29 mm; anterior and posterior margins arcuate; lateral margins strongly rounded in anterior third and convergent caudad; anterior and posterior pronotal corners broadly rounded; narrow basal part of pronotum demarcated by indistinct lateral constriction and narrow but shallow dorsal transverse groove. Punctures and setae as those on head, fine and sparse, inconspicuous.

Elytra ( Fig. 10 ) in lateral view more convex than pronotum, in dorsal view slightly rhomboidal in shape, with well-defined broadest place located near middle, strongly narrowing anterad and caudad; EL 0.75 mm, EW 0.48 mm, EI 1.58; elytral base as broad as pronotal base; humeri barely marked as indistinct elongate wrinkles; elytral base without impressions; suture slightly raised in anterior fourth; elytral apices separately rounded. Punctures as fine and inconspicuous as those on head and pronotum; setae more distinct than those on other body parts, short and sparse, nearly recumbent. Hind wings well developed.

Legs ( Fig. 10 ) long and slender; femora distinctly clavate with slender proximal parts; all tibiae straight; tarsi long and robust.

Aedeagus ( Figs. 18–19 ) stout, AeL 0.25 mm, lightly sclerotized, with complicated internal armature composed of elongate and curved sclerites protruding distally; parameres slender, each with two apical setae.

Distribution. South Australia, known only from the Eyre Peninsula, Port Lincoln.

Remarks. The holotype male is accompanied by two specimens of ants Pachycondyla lutea ( Mayr, 1862) ( Figs. 20–21 ) and was presumably collected in or near an ant colony. This species of ponerine ant was listed by O'Keefe (2000) as associated with Palaeoscydmaenus australiensis (misspelled as australis), presumably on the basis of a misinterpretation of the data given by Franz (1975). The latter author stated that the holotype of P. australiensis is accompanied by two ant specimens mounted on a card placed on the same pin together with the beetle, but he did not identify the ants. The name Ponera lutea (= Pachycondyla lutea ) appears in the same Franz's paper in association with an undetermined female of Palaeoscydmaenus sp. preserved in The Natural History Museum, London and collected in a company of this ant species.

Figures

FIGURES 10 – 12. Holotype male of Palaeoscydmaenus australiensis. Dorsal habitus (10), simplified ventral habitus (11) and original set of labels (12).

FIGURES 13 – 17. Holotype male of Palaeoscydmaenus australiensis. Head in dorsal (13) and ventral (14) views; right antenna in dorsal view (15); prothorax in ventral view (16); and pterothorax in ventral view (17). Abbreviations: ai—asetose impression; ar—anterior ridge; bs—basistipes; cc—procoxal cavity; cd—cardo; cl—clypeus; cs—procoxal socket; fr—frons; gal—galea; gen—gena; gp—gular plate; h—hypostoma; hr—hypostomal ridge; hy—hypomeron; lac—lacinia; lp 2 – 3 — labial palpomere 2 – 3; mcc—mesocoxal cavity; mcp—mesocoxal projection; mcs—mesocoxal socket; md—mandible; mfa—metafurcal arm; mn—mentum; mxp 1 – 4 — maxillary palpomere 1 – 4; nr—neck region; nss—pronotosternal suture; occ—occipital constriction; pfa—profurcal arm; pl—posterior lobe; pre—prepectus; ps—prosternum; smn—submentum; tm—temple; v—vertex; v 2 — mesoventrite; v 3 — metaventrite; vp 2 — mesoventral intercoxal process; vp 3 — metaventral intercoxal process.

FIGURES 18 – 19. Aedeagus of Palaeoscydmaenus australiensis in ventral (18) and lateral (19) views.

FIGURES 20 – 21. Ant Pachycondyla lutea collected together with the holotype of Palaeoscydmaenus australiensis. Lateral habitus (20) and head in frontal view (21).