Plaumanniola Costa Lima

Plaumanniola Costa Lima, 1962: 415 . Type species: Plaumanniola sanctaecatharinae Costa Lima, 1962 (monotypy).

Revised diagnosis. Head strongly broadened and flat, with lateral margins divergent caudad, with bristles on tempora and along posterior margin of vertex; occipital constriction narrower than 1/3 of HW; 'neck' region only slightly broader than occipital constriction and narrower than 1/3 of HW; mouthparts not visible in dorsal view; submentum not demarcated laterally from postcardinal parts of hypostomae; hypostomal ridges long and divergent caudad; labrum with deeply emarginate anterior margin; maxillary palps flattened dorso-ventrally, with enlarged palpomere III and subconical, pointed palpomere IV; antennae massive and clubbed; pronotum broad and flattened, without pits or grooves and with sharp lateral edges; prosternum without prosternal intercoxal carina or process; procoxal sockets closed; hypomera with incomplete hypomeral ridges; pronotosternal sutures entire; mesoventrite with keel-like, high and narrow mesoventral intercoxal process and indistinctly delimited lateral asetose impressions (= procoxal rests); each elytron with two barely discernible rudiments of asetose basal foveae; metaventral intercoxal process long and narrow, with deep and narrow posterior emargination, narrowly separating transverse metacoxae; aedeagus with complex internal armature and free (i.e., not fused with median lobe) parameres bearing apical and subapical setae.

Redescription. Body of male (Figs. 1, 3) stout and broad, with flat head (Figs. 6–7), more convex pronotum (Fig. 7) and strongly convex elytra, with deep constrictions between head, pronotum and elytra, brown and densely setose, BL 1.90–2.58 mm.

Head (Figs. 4–7, 8) strongly flattened and broadened, in dorsal view approximately subtrapezoid or subtriangular, broadest near posterior margin of vertex; occipital constriction (Fig. 8; occ) in the narrowest place narrower than 1/3 of HW; 'neck' region (Fig. 8; nr) only slightly broader than occipital constriction and narrower than 1/3 of HW; tempora (Figs. 4–5) long and divergent caudad, with bristles; vertex (Figs. 4–5) strongly transverse, moderately convex, not projecting dorso-caudad, with arcuate or nearly straight posterior margin dorsally sharply demarcated from 'neck' region; frontoclypeal region (Figs. 4–5) only partly visible in dorsal view, its anterior part rapidly deflexed; fronto-clypeal groove absent; antennal insertions moderately broadly separated, located on antero-ventral margin of head; compound eyes (Figs. 4–7) located in anterior or median part of head, small to large, multifaceted, composed of large and coarse ommatidia, with broadly emarginate posterior margin.

Mouthparts located on ventral side of head. Labrum (Fig. 6) transverse with deeply emarginate anterior margin. Mandibles (Figs. 6, 8; md) directed antero-ventrad, symmetrical, each with broad basal part, without noticeable prostheca, and with slender and curved distal part, without mesal tooth. Each maxilla (Fig. 8) with subtriangular basistipes (Fig. 8; bst), elongate galea (Fig. 8; gal) and lacinia (Fig. 8; lac) and moderately long, flattened dorso-ventrally maxillary palp (Fig. 8; mxp) composed of tiny and parallel-sided palpomere I about twice as long as broad, strongly elongate, pedunculate and curved palpomere II broadest in distal third, broad and stout palpomere III broadest in distal third and about twice as long as broad, and small, subconical and pointed palpomere IV with rapidly narrowing small apical part.

Labium (Fig. 8) with large and transverse submentum (Fig. 8; smn) not demarcated from gular plate (Fig. 8; gp) and laterally fused with postcardinal parts of hypostomae, subtrapezoidal mentum (Fig. 8; mn); and short prementum bearing narrowly separated at bases long 3-segmented labial palps (Fig. 8; lp). Hypostomal ridges (Fig. 8; hr) long and divergent caudad but not reaching posterior tentorial pits (Fig. 8; ptp), which are well-visible in ventral view.

Gular plate (Fig. 8; gp) large and convex; gular sutures indiscernible.

Antennae (Figs. 4–6, 11) relatively short and massive, flattened dorso-ventrally, either with sharply demarcated club composed of enlarged antennomeres VII–XI or gradually thickened from antennomere IV to X, antennomere XI narrower than X; antennomeres covered with long, dense and suberect vestiture and sparse long and strongly erect setae.

Prothorax strongly flattened and broad. Pronotum (Figs. 1–2) in dorsal view oval with a large part of base abruptly expanded caudad and forming sharply separated lobe about as broad as anterior part of mesothorax; anterior pronotal corners indistinct or absent; sides rounded; posterior corners rounded; basal margin nearly straight; lateral margins forming sharp and complete edges; base of pronotum without foveae, impressions or grooves; pronotum without bristles.

Prosternum (Fig. 9; pst) slightly broader than long, with long but not demarcated precoxal (basisternal) part; procoxal cavities (Fig. 9; pcc) not separated by intercoxal carina or process; procoxal sockets (Fig. 9; pcs) closed by lateral lobes of postcoxal part of sternum. Hypomera (Fig. 9; hy) broad and elongate; hypomeral ridge (Fig. 9; hyr) visible only in posterior half of hypomeron; pronotosternal sutures (Fig. 9; nss) entire.

Mesoscutellum very small, not visible in intact specimens, subtriangular, transverse, mesoscuto-scutellar suture present.

Mesoventrite (Fig. 10) with narrow anterior ridge (Fig. 10; ar) connected in middle with anterior part of long, narrow and strongly expanding ventrad (i.e., keel-shaped) mesoventral intercoxal process (Fig. 10; msvp); mesanepisternum with long prepectus (Fig. 10; pre) and posterior part (Fig. 10; aest2) largely visible in ventral view; mesepimeron not visible in ventral view; sides of mesothorax without foveae; mesoventrite with indistinctly delimited subtriangular lateral asetose impressions (Fig. 10; ai); mesocoxal projections (Fig. 10; mcp) without posterior lobes and without bristles, with mesocoxal sockets (Fig. 10; mscs) located on their mesal surface (not exposed in ventral view); anterior and posterior margins of mesocoxal cavities (Fig. 10; mscc) without carinae; mesofurcal fovea (Fig. 10; msff) small and located in sub-anterior region of mesocoxal cavity.

Metaventrite (Fig. 10; v3) strongly transverse, anteriorly fused with mesoventrite, posteriorly deeply bisinuate and with narrow but long median subtrapezoidal metaventral intercoxal process (Fig. 10; mtvp) bearing subtriangular median emargination. Metanepisterna nearly completely, and metepimera partly visible in ventral view, narrow.

Metafurca in transparent mount not visible, possibly directed dorso-anterad or short and obscured by thick integument of posterior metaventral margin.

Elytra (Figs. 1–2) oval, each with two barely discernible asetose rudiments of basal foveae, without basal impressions; humeral calli distinct; subhumeral lines absent; elytral apices non-modified, separately rounded.

Legs (Figs. 1–2, 9–11) moderately long, robust; procoxae (Fig. 9) subglobose, mesocoxae (Fig. 10) oval and slightly elongate, metacoxae (Fig. 10) transverse, stout; all trochanters short and non-modified; all femora strongly flattened dorso-ventrally, each with tibial groove on posterior surface, in which posterior margin of tibia fits; tibiae flattened dorso-ventrally, with carinate posterior margin; tarsi moderately long, slender.

Abdominal sternites (Figs. 10–11) unmodified, sternites III–VI subequal in length, VII much longer, suture between VII and VIII barely marked.

Aedeagus (Figs. 12–15) stout, with narrowing and subtriangular apical part of median lobe; internal armature complex and darkly sclerotized; parameres free (i.e., not fused with median lobe) and slender, bearing apical and subapical setae.

Spermatheca not studied (due to lack of available female specimens), but Costa Lima (1962) illustrated two female specimens photographed in transparent mounts with darkly sclerotized spermatheca clearly visible inside metathorax. It is hemispherical with distinct and short duct of accessory gland (Costa Lima 1962; Figs. 2–3).

Distribution and composition. Two species are known from Brazil.