Triplatyx bilobatus Cachan, 1952

Kment, Petr, 2008, A revision of the endemic Madagascan genus Triplatyx (Hemiptera: Heteroptera: Pentatomidae), Acta Entomologica Musei Nationalis Pragae 48 (2), pp. 543-582 : 550-554

publication ID	https://doi.org/ 10.5281/zenodo.5341677
DOI	https://doi.org/10.5281/zenodo.5444282
persistent identifier	https://treatment.plazi.org/id/A303878B-FFFF-1519-FE62-B4C88D5C8B3A
treatment provided by	Felipe
scientific name	Triplatyx bilobatus Cachan, 1952
status

Treatment

( Figs. 1 View Figs , 8 View Figs , 15, 19 View Figs , 29 View Figs , 35-36 View Figs , 47 View Figs , 53 View Figs a-b, 67-71, 84, 86)

Triplatyx bilobatus Cachan, 1952: 374-376 . Description, key.

Type locality. Madagascar, Androy region, Ambovombe [25°11′N, 46°03′E].

Type material examined. HOLOTYPE: J, ‘MUSEUM PARIS / MADAGASCAR / RÉGION DE L’ANDROY / AMBOVOMBE / Dr J. DECORSE 1901 [p, white label] // fév. & mars [p, white label] / 1901 // TYPE [p, red label] // Triplatyx / bilobatus / n. sp. / Cachan det.[hw, white label]’ ( MNHN).The holotype ( Figs. 69-70 View Figs ) is pinned through the scutellum by a micro-pin pushed into a piece of card; pygophore missing.

Additional material examined. MADAGASCAR: Isalo National Park, Amboandrika forest, 19.i.2007, 1 J, Z. Mráček lgt. ( NMPC).

Redescription. Adult ( Figs. 67-71 View Figs View Figs ). Colouration. Body generally dark brown to black, with smaller or larger ivory callosities scattered on both dorsal and ventral surfaces. Eyes pale brown. Lateral spines on anteromedian angles of pronotum whitish. Antennomere 1 dark brown; antennomeres 2 and 3 beige, antennomere 3 slightly darkened apically; antennomere 4 brownish and antennomere 5 dark brown, both with paler bases. Fore coxae, apical thirds of femora, and entire tibiae whitish ( Fig. 68 View Figs ); tibiae with three more or less regular brownish rings; very apices of tibiae and entire tarsi pale brown; apices of claws black. Each laterotergite with medial whitish spot in outer half both on dorsal and ventral sides.

Sculpture. Dorsal surface deeply and very densely punctate; punctures dark brown to black; interspaces among punctures smaller than their diameters, with scattered small callosities which are very small on head, connexivum and most of anterior part of pronotum and scutellum. Anterior part of pronotum medially with large callosities forming elevated triangular ridge, widening posteriorly and reaching midlength of pronotum ( Figs. 67, 70 View Figs ); posterior part of pronotum with several small callosities, one of them in middle of posterior margin. Scutellum with basal angles shallowly depressed, with globular callose grain present anteriorly near inner margin of each depression; several larger callosities in posterior third of scutellum. Hemelytra with scattered large callosities, widely coalescent in posteromedian part of corium. Femora and tibiae with distinct concolorous punctures. Ventral surface of body with dense deep punctures and very few callosities, only abdominal venter medially with large, not elevated, coalescent callosities and sparse punctures ( Fig. 68 View Figs ).

Structure. Head only slightly declivous, nearly quadrangular in outline ( Fig. 1 View Figs ). Lateral margin in front of eyes with narrowly triangular anteocular spine, deeply incised; paraclypei flattened but little expanded laterally, narrowing anteriad in front of lateral incision, straight, than rounded mesad anteriorly, meeting in front of clypeus and forming there distinct incision; paraclypei and clypeus anteriorly depressed; anterior margin of paraclypei both dorsally and ventrally with erect pale setae. Clypeus and frons usually only slightly convex. Antennomeres ordered from shortest to longest as 1 <3 <2 <4 <5, antennomere 2 distinctly longer than each of antennomeres 1 and 3. Bucculae both anteriorly and posteriorly nearly rectangular, their lower margin straight. Apex of rostrum reaching anterior margins of metacoxae ( Fig. 68 View Figs ).

Pronotum ( Figs. 8 View Figs , 70 View Figs ). Anterolateral angles truncated, laterally with long, slender spine curved towards eye. Anterolateral margins concave, not carinate, with three slender spines on each side. Humeral angles slightly produced anteriad and dorsad, separated from pronotal disc by shallow depression, each bearing 4-6 spine-like to lobe-like projections. Margins behind humeral angles nearly straight, narrowing towards scutellum. Posterior margin slightly concave. Disc in anterior part flat, declivous anteriad, uneven, with distinct triangular elevation medially, and one less conspicuous oval submedian elevation on each side; median and submedian elevations separated by deep and narrow furrow reaching nearly anterior margin of pronotum, then turning laterad and nearly reaching anterolateral angles; submedian elevations laterally and posteriorly emarginated by shallow depressions. Posterior part of pronotum distinctly convex, separated from scutellum by V-shaped furrow ( Fig. 71 View Figs ).

Scutellum. Basal angles narrowly depressed. Disc strongly elevated in anterior half, forming conical, apically rounded hump, distinctly detached from pronotum ( Fig. 71 View Figs ), posterior third nearly flat; median longitudinal ridge not developed.

Hemelytra. Clavus with three irregular rows of punctures in widest place; apex of membrane not surpassing apex of abdomen ( Figs. 67, 69 View Figs ).

Thorax ventrally convex (most of all Triplatyx species ); sternum between coxae shallowly furrowed ( Fig. 68 View Figs ). Ostiole situated on rather large tubercle, round, transverse and directed laterad ( Fig. 19 View Figs ), accompanied with small auricle ( Figs. 19 View Figs ), approximately twice longer than ostiole wide, metapleuron around ostiole distinctly depressed. Evaporatorium large, developed both on meso- and metapleuron, present as narrow but distinct strip along posterior margin reaching posterolateral angle on mesopleuron ( Fig. 15 View Figs ) and rather widely surrounding the tubercle bearing ostiole on metapleuron where projecting as narrow strip mesad between meso- and metacoxae, and laterad on anterior margin of metapleuron along thoracic spiracle. Posterior margin of posterolateral angle of mesopleuron slightly depressed, forming an ‘outlet channel’; channel less deep and conspicous than in remaining species; gyrification well developed.

Legs. Protibiae distinctly widening towards apex ( Fig. 70 View Figs ), outer surface strongly flattened, lateral margin forming sharp ridge.

Abdomen slightly narrower than pronotum across humeral angles. Sternite III not depressed anteromedially. Laterotergites and lateral margins of mediotergites exposed dorsally; outer margins of laterotergites strongly sinuate, each laterotergite bilobate with one anterior and one posterior lobe ( Figs. 29 View Figs , 67, 69 View Figs ); dorsal surface of laterotergites uneven, lateral margin depressed in outer half near midlength.

Male genitalia. Pygophore ( Figs. 35-36 View Figs ) relatively large (pygophore width 0.90 mm, ratio pygophore width to body length 0.19); ventral wall slightly gibbose, ventral rim well developed, low but sharp, ventral rim infolding wide, bent dorsally, shallowly U-shaped medially, lateral projection obtusangulate ( Fig. 36 View Figs ); posterolateral angles widely rounded laterally; lateral rim infolding without projection; apices of parameres visible, directed dorsad. Paramere simple, laterally flattened, apical portion basally curved, apically widely rounded ( Fig. 47 View Figs ); apex of paramere, in dorsal view, slightly widened and flattened. Phallotheca of aedeagus oval, sclerotized apical processes of median penal plates well developed ( Fig. 53 View Figs ).

Female. Unknown.

Measurements (all in mm). See Table 1. The holotype (J): body length 5.1; head: length 1.4, width 1.45, interocular width 1.0; length of antennomeres: 1 – 0.25, 2 – 0.4, 3 – 0.33, 4 – 0.43, 5 – 0.6; pronotum: length 1.25, width 3.85; scutellum: length 2.0, width 1.9.

Variation. Both specimens differ in the shades of body colouration (callosities on pronotum reddish in holotype ( Fig. 70 View Figs ), ivory in the other male ( Fig. 67 View Figs )), the shape of paraclypei (convex in holotype, slightly incised in the other male), and the shapes of humeral angles and spines on anterolateral margin of pronotum.

Differential diagnosis. Smallest species of the genus, dark to blackish brown, easy to be identified by the following combination of characters: head nearly quadrangular, deeply insinuated in front of anteocular spine, paraclypei arcuate laterally and anteriorly, leaving wide triangular incision against tip of clypeus; anterior margin of head setose; bucculae anteriorly straight, rectangular; pronotum uneven, bearing large triangular pale elevation in anterior part; anterolateral angles of pronotum spinose, not carinate; posterior part of pronotum and anterior part of scutellum, in lateral view, forming sharp angle; scutellum with high, conical hump in its anterior half, lacking longitudinal ridge; legs punctate, protibiae widening towards apex; lateral margin of connexivum strongly sinuate; and details of male genitalia.

Collecting notes. The specimen from Isalo National Park was collected in the Amboandrika forest ( Fig. 84 View Figs ) by beating lower parts of tree branches (M. Trýzna, pers. comm.). Both known specimens were collected between January and March. Triplatyx bilobatus was collected together with T. dubius at the locality of Ambovombe.

Distribution. So far known only from two localities in southern Madagascar (Fig. 86).