Diastatotropis arofaniana Trýzna & Baňař, 2022

Trýzna, Miloš & Baňař, Petr, 2022, Diastatotropis arofaniana sp. nov. from eastern Madagascar, a new species close to D. rubra Frieser, with a redescription of the type of the latter, and notes on morphology (Coleoptera: Anthribidae), Zootaxa 5120 (1), pp. 30-52 : 34-40

Diastatotropis arofaniana Trýzna & Baňař sp. nov.

( Figs 9–31 , 43–48 , 51 )

Type locality. E Madagascar, secondary but well-preserved forest in Parc National d´Analamazaotra , S 18°57´07´´; E 48°25´51´´, 1020 m.

Type material. Holotype (male): E MADAGASCAR, TOAMASINA PROVINCE: ‘E Madagascar, 16.-21.i.2017, / Andasibe N.P., Analamazaotra, / circuit Aventure , 1020 m, / S 18°57´07´´; E 48°25´51´´, / M. Trýzna leg.’ [p] ( MMBC) . Allotype (female): the same data as holotype ( MTDC) . Paratypes (3 males, 3 females): 1 male, 2 females: the same data as holotype; 1 male: ‘ Madagascar, 964 m, / Mantadia N.P., 30.i.2019, / Tsakoka circuit, / S 18°47´30.3´´, E 48°25´37.2´´, / primary forest, M. Trýzna leg.’ [p]; 1 male: ‘ Madagascar / Toamasina distr. / Analamazaotra env. / 3.- 8.12.1997 / Jiří Stolarczyk lgt.’ [p] (all in MTDC) ; 1 female: ‘ Madagascar / Annananarivo / ( Sikora ) // Karl Jordan Coll. / B M. 1940-109.’ [p] ( BMNH) .

Red label [p] HOLOTYPE / ALLOTYPE / PARATYPE / Diastatotropis / arofaniana sp. nov. / M. Trýzna & P. Baňař det., 2022.

Identification. Small-sized species (ca. 6.0– 7.4 mm), rather more oval than elongate ( Fig. 9 , 14 ). Elytra distinctly convex, forming wide regular arch in lateral view, without sub-basal tubercles ( Fig. 13 ). Rostrum with only one central longitudinal carina, lateral carinae absent; central carina distinct, reaching beyond posterior margins of eyes ( Fig. 11 , 17 ). Antennae relatively short ( Fig. 12 , 16 ), antennomeres III–VIII gradually widened and smoothing continuing to antennal club (in both sexes). Disc of pronotum with shallow transverse imprint in anterior part better visible in lateral view) ( Fig. 13 ). Surface of the whole body, including its lower part, reddish, especially head and pronotum crimson red. Elytra black, only narrow margins of elytra reddish (female paratype in BMNH with elytra only black, without reddish margins). Scape, pedicel and antennomeres III–VII reddish, VIII–XI contrasting black. Legs reddish, distal part of tibiae and tarsomeres light brown.

Description. Male holotype (female allotype). Measurements (in mm): Total body length—6.09 (6.35). Head: total length—1.39 (1.40); length of rostrum—0.70 (0.73); maximum width of rostrum—1.07 (1.19); length of eye— 0.71 (0.71); maximum width across eyes—1.29 (1.41); minimum distance between eyes—0.36 (0.50). Antenna: length of segments: II—0.20 (0.21), III—0.20 (0.20), IV—0.23 (0.17), V—0.16 (0.11), VI—0.11 (0.09), VII—0.13 (0.11), VIII—0.10 (0.09), IX—0.33 (0.33), X—0.16 (0.16), XI—0.31 (0.31), width of segment IX—0.37 (0.50). Pronotum: maximum length—1.43 (1.46); width at carina (= maximal width in this case)—2.14 (2.31); minimum width—1.31 (1.64). Elytra: maximum length—3.38 (3.40); maximum width—2.80 (2.88). Pygidium: maximum length—0.55 (0.55); maximum width—0.80 (0.88).

Coloration of the cuticle of entire body largely reddish, head and pronotum crimson red. Disc of elytra, antennomeres VIII–XI and inner margins of mandibles contrasting black. Scutellum and humeri light-coloured. Distal part of tibiae and tarsomeres including claws light brown. ( Figs 9–19 ).

Vestiture. Head with sparse reddish to yellowish appressed setae, denser along central longitudinal carina on rostrum and around eyes ( Figs 11 , 17 ). Labrum light reddish to yellowish with a few longer light-coloured setae in distal part. Antennomeres III–IX with distinct subdecumbent setae: III–VIII with reddish, VIII with black setae; IX–XI with appresed black setae ( Figs 12 , 16 ). Pronotum, including pronotal declivity, with sparse appressed crimson red setae ( Figs 10 , 15 ). Elytra with very fine, delicate, indistinct and sparse appressed setae, their colour corresponds to surface of elytra: light-coloured on black disc of elytra and reddish on its margins ( Figs 9, 13–14 ). All legs covered with dense appressed reddish to yellowish setae, tibiae with subdecumbent setae in inner part. Tarsomeres with light-brownish setae ( Figs 9 , 14 ). Whole ventral part of body and pygidium covered with indistinct sparse appressed reddish setae.

Structure. Head ( Figs 11 , 17 ) rather shorter, rostrum wider than long, ratio of rostrum length to maximum width 0.65 in male, 0.61 in female. Rostrum slightly bent upwards, not flat in lateral view. Lateral sides of rostrum weakly extended apically. Dorsal part of rostrum with only one central longitudinal carina, two lateral carinae absent. Central carina distinctly developed, not extended distal part of rostrum and reaching vertex behind posterior margin of eyes. Eyes elliptical, not emarginate, dorsal ocular index 0.77 in male, 1.10 in female. Ratio of maximum width across eyes to maximum width of rostrum 1.21 in male, 1.18 in female.

Antennae ( Figs 12 , 16 ) reaching to posterior margin of pronotum in male, female antennae imperceptibly shorter, reaching only to dorsal transverse carina of pronotum. Scape not swollen, of the same width as pedicel, rest of antennomeres flattened, gradually widened and fluently continue to antennal club in both sexes. Antennomere IX transverse, ratio of its maximum length to maximum width 0.89 in male, 0.66 in female.

Pronotum ( Figs 10 , 15 ) transverse, ratio of its length to maximum width 0.67 in male, 0.63 in female, the widest in dorsal transverse carina, then narrowed to distal part. Disc of pronotum with shallow transverse imprint in anterior part (better visible in lateral view). Dorsal transverse carina slightly sinuated, not interrupted in middle. Lateral carinae of pronotum short, not reaching half of length of pronotum, widely rounded at contact with dorsal transverse carina.

Elytra ( Figs 9 , 14 ) short, rather oval, without sub-basal tubercles, ratio of the maximum length to maximum width of elytra 1.21 in male, 1.18 in female. Elytral intervals completely flat, dorsal punctures very small and inconspicuous, their diameter much smaller than distance of individual punctures.

Pygidium ( Figs 20 , 27 ) transverse, ratio of the maximum length to maximum width 0.69 in male ( Fig. 20 ), 0.63 in female ( Fig. 27 ).

Male terminalia. ( Figs 21–26 ). Sternite VIII ( Fig. 21 ) semicircular, its halves vaguelly separted, compact, inconspicuously delimited posteriorly [fused?], tergite VIII sligthly overlapping sternite VIII anteriorly, ostium very short and broad, triangle shaped. Aedeagus ( Figs 22–24 ) slender, tiny, pedon and tectum wide, tectum inconspicuously overlapping pedon, its apex bent dorsally, apex of pedon very strongly bent dorsally in lateral view ( Fig. 24 ). Apodemes long, continuosly widening posteriad in lateral view ( Fig. 24 ), moderately curved. Internal sac with very fine serration, noticeable under high magnification only, ejaculatory duct very long. Tegmen ( Fig. 25 ) relatively robust with long apodeme, tegminal plate very wide, basal piece with two conspicuous, roughly, sclerotized spurs oriented posteriorly. Apex of tegmen ( Fig. 26 ) with group of long and thick setae.

Female terminalia. ( Figs 28–31 ). Sternite VIII ( Fig. 28 ) with broadly concave anterior margin and strongly sclerotized apodeme. Tergite VIII ( Fig. 29 ) sub-rectangular, its anterior margin straight. Ovipositor ( Fig. 30 ) wide and short, lateral rods diverging. Hemisternites unarmed, simple, without toothed plates, with only sub-apically placed stylus each ( Fig. 31 ). Bursa copulatrix large, not studied in detail ( Fig. 30 ).

Sexual dimorphism. Generally, not very conspicuous. Male: very slightly more slender, distance between eyes smaller (dorsal ocular index 0.77), antennae slightly longer, reaching posterior margin of pronotum, abdominal ventrites flat in middle. Shape of pygidium as in Fig. 20 . Female: more robust, distance between eyes larger (dorsal ocular index 1.10), antennae shorter, only reaching dorsal transverse carina of pronotum, abdominal ventrites convex. Shape of pygidium as in Fig. 27 .

Variability. The female paratype (in BMNH) from ‘Annananarivo’ has the entire elytra black, without reddish margins. The male paratype from Analamazaotra (lgt. Stolarczyk, in MTDC) has head and pronotum light red, antennomeres I–VII, scutellum, humeri and all legs yellowish to light brownish.

Etymology. The species name arofaniana is derived from the Malagasy word arofanina meaning handrail, banister. The name refers to the fact that the new species was collected almost exclusively on the wooden railings of stone stairs on the forest path (see below).

Collecting circumstances. Most specimens of the type series (including the holotype) were collected in wellpreserved secondary forest in Analamazaotra ( Figs 43–44 ) on a wooden handrail installed along the stone steps on a hiking trail on the ‘Aventure’ circuit ( Figs 45–46 ). This wooden handrail was made from logs ca. 10 cm in diameter, from an unspecified deciduous tree. At the time of construction, the handrail was completely debarked, and painted with industrial brown paint. At the time of collection, i.e. several few years after construction, the paint had already been damaged locally, partially peeling off, but it still covered more than 90% of the surface of the wooden railing. Only in a few cases was the wood of the handrail sufficiently exposed that small fruiting bodies of unspecified fungi already grew from it. Collecting on the handrail was carried out for 4 days (between 16–18 January, 2017).

A simple method was used: sweeping the lower side of the horizontal parts of the wooden handrail (for methods see also Trýzna and Baňař 2012). Although collecting was also done on dead and dying wood in the vicinity, no other specimens were found there.

Together with Diastatotropis arofaniana other species of anthribids were also found on the handrail, e.g. members of the genera Diastatotropis and Lemuricedus .

Only one specimen that we collected of the type series was from natural wood. This male was captured on dead wood of an unspecified deciduous tree species in primary forest along the forest path of the ‘ Tsakoka’ circuit in Parc National de Mantadia ( Figs 47–48 ) .

Note: In the forests of these both protected areas, wooden handrails are often built on forest paths. These handrails are built along stairs in sloping terrain, or as part of small bridges that cross small watercourses. It was accidentally discovered a few years ago, that handrails are widely used by miscellaneous species of anthribids. Thus, it is possible to find here, for example, species of the genera Apatenia , Caranistes , Diastatotropis , Lemuricedus , and some representatives of the subfamily Choraginae . Some of these handrails are built from natural wood, and at the time of collecting they were still covered with more or less intact bark. However, it was a surprise to us, that many species were also found on debarked handrails, moreover ones that were painted with industrial paint ( Figs 49–50 ).

Distribution. E Madagascar, Toamasina province. The species is only known from the type locality Parc National d´Analamazaotra, and from Parc National de Mantadia. These two localities are ca. 16 km apart by air. One female with locality label ‘ Madagascar, Annananarivo’ (in BMNH) does not provide a more accurate locality.

According to Moravec (2007: 18) locality labels with ‘Annanarivo’ (often labelled so by insect dealers) refer to “larger area of Antananarivo, probably including the Angavo massif (Anjozorobe) north-east of the capital, or they were simply used by insect dealers instead of ‘Madagascar’”.

Differential diagnosis. Diastatotropis arofaniana may be confused with D. rubricollis , but particularly with D. rubra . These three species can be distinguished from each other by the characters given in the following key:

1 Rostrum approximately as long as wide, flat, not bent (observed in lateral view); with one central longitudinal carina and two lateral carinae irregularly and crookedly developed. Dorsal side of head and disc of pronotum with coarse, dense sculpture. Upper side of body matt. All antennomeres completely black or deep blue.................... D. rubricollis (Fairmaire)

- Rostrum distinctly wider than longer, slightly bent upwards, or with shallow transverse impression in line of scrobes (observed in lateral view); with only one central longitudinal carina, two lateral carinae absent. Dorsal side of head with very fine, delicate and sparse sculpture, disc of pronotum smooth, almost without any structure. Upper side of body shiny, especially disc of pronotum and elytra polished. At least scape distinctly reddish................................................. 2

2 Antennomeres III–VII thin (only female holotype known), VIII twice as wide as VII and thus part of four-segmented antennal club ( Fig. 34 ). Elytra rather sub-oval, ratio of maximum length to maximum width 1.46; disc of elytra rather flat in lateral view ( Figs 32, 36 ). Disc of pronotum regularly convex, without any transverse impression in anterior part ( Fig. 33, 36 ). Whole body brick red, scape brick red, only pedicel and antennomeres III–VIII dark brownish to black, and IX–XI markedly black ( Figs 32–36 )................................................................................ D. rubra Frieser

- Antennomeres III–VIII gradually widened and smoothly continue to antennal club (in both sexes) ( Figs 12 , 16 ). Elytra rather oval, ratio of maximum length to maximum width 1.21 in male, 1.18 in female; disc of elytra distinctly convex and forming wide regular arch in lateral view ( Figs 9, 13 , 14 ). Disc of pronotum with shallow transverse impression in anterior part (better visible in lateral view) ( Figs 10 , 15 ). Whole body red, especially head and pronotum crimson red, only disc of elytra and antennomeres VIII–XI markedly black ( Figs 9–17 ).......................... D. arofaniana Trýzna & Baňař sp. nov.

Figures

FIGURE 51. Distribution of Diastatotropis arofaniana, red circle—type locality; green circle—other distribution.

FIGURES 9–13. Diastatotropis arofaniana, male holotype; 9, dorsal habitus; 10, pronotum in dorsal view; 11, head in dorsal view; 12, right antenna in dorsal view; 13, lateral habitus [apex of left hindtibia and hindtarsus omitted from the picture]. Scale bars in mm.

FIGURES 14–17. Diastatotropis arofaniana, female allotype; 14, dorsal habitus; 15, pronotum in dorsal view; 16, right antenna in dorsal view; 17, head in dorsal view. Scale bars in mm.

FIGURES 18–19. Diastatotropis arofaniana, Parc National d´Analamazaotra, specimens with dissected terminalia; 18, male paratype, dorsal habitus; 19, female paratype, dorsal habitus. Scale bars in mm.

FIGURES 20–26. Diastatotropis arofaniana, Parc National d´Analamazaotra, male paratype, terminalia; 20, pygidium in dorsal view; 21, segment VIII, and sternite IX (= spiculum gastrale) in ventral view; 22, apex of aedeagus in ventral view; 23, aedeagus in ventral view; 24, aedeagus in lateral view; 25, tegmen in ventral view; 26, apex of tegmen in ventral view. Scale bars in mm.

FIGURES 27–31. Diastatotropis arofaniana, Parc National d´Analamazaotra, female paratype, terminalia; 27, pygidium; 28, sternite VIII; 29, tergite VIII; 30, ovipositor with bursa copulatrix in ventral view; 31, apex of ovipositor with subapical stylus, ventral view. Scale bars in mm.

FIGURES 43–44. Collecting site of Diastatotropis arofaniana in Parc National d´Analamazaotra, Aventure circuit, 2017.

FIGURES 45–46. Wooden handrails on the type locality of Diastatotropis arofaniana in Parc National d´Analamazaotra, Aventure circuit, 1020 m a.s.l., 2017.

FIGURES 47–48. Diastatotropis arofaniana, Parc National de Mantadia, Tsakoka circuit, 964 m a.s.l., 2019; 47, collecting site of paratype; 48, microhabitat of the locality.

FIGURES 49–50. Parc National de Mantadia, Tsakoka circuit. Samples of debarked wooden handrails, painted with industrial paint, nevertheless widely used by miscellaneous species of anthribids.

FIGURES 32–36. Diastatotropis rubra Frieser, 1992, female holotype; 32, dorsal habitus; 33, pronotum in dorsal view; 34, right antenna, dorsal view; 35, head in dorsal view; 36, lateral habitus. Scale bars in mm.