Arumatia diamante Ghirotto, 2022

Ghirotto, Victor Morais, Crispino, Edgar Blois, Engelking, Phillip Watzke, Neves, Pedro Alvaro Barbosa Aguiar, Góis, Júlia de & Chiquetto-Machado, Pedro Ivo, 2022, Arumatia, a new genus of Diapheromerinae stick insects (Insecta, Phasmatodea) from Brazil, with the description of five new species and a reassessment of species misplaced in Australian genera, European Journal of Taxonomy 827 (827), pp. 1-85 : 70-77

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Arumatia diamante Ghirotto

gen. et sp. nov.

Arumatia diamante Ghirotto gen. et sp. nov.

Figs 47–51 View Fig View Fig View Fig View Fig View Fig , 52 View Fig , 53I View Fig



Differs from all other known females of Arumatia gen. nov. by the presence of two large tubercles on tergum VI. It further differs from all other known females of Arumatia except A. motenata gen. et sp. nov. by the very elongate subrectangular head, the longer microtrichia on the galea, the absence of stronger spiniform setae on the carinae of the tarsi and on the apex of the mid and hind tibiae, the presence of an apical sessile spine on the apex of the ventral, antero- and posteroventral carinae of the tibiae, the very elongate epiproct, the shorter subgenital plate and the wider gonoplac in lateral view. It further differs from A. dubia gen. et comb. nov. and A. fulgens gen. et comb. nov. by the shorter median segment in relation to the metanotum, the slightly shorter cerci and the longer gonapophyses VIII, from A. anyami gen. et sp. nov. by the less emarginate posterior margin of tergum X, from A. crassicercata gen. et sp. nov. by the shorter median segment in relation to the metanotum and the longer cerci, from A. aramatia gen. et sp. nov. by the shorter median segment in relation to the metanotum, the shorter cerci and the longer gonapophyses VIII, and from A. motenata by the more elongate head, the proportionally shorter cerci and the longer epiproct and paraprocts.


Eggs of Arumatia diamante gen. et sp. nov. can be differentiated from eggs of all other species whose eggs are known except A. aramatia gen. et sp. nov. by the large and not constricted opercular collar. Eggs of

A. diamante differ from those of A. aramatia by the straight, not sinuous ridges of the capitulum.


The specific epithet “ diamante ” is Portuguese for “diamond” referring both to the type locality, the diamond-bearing Chapada Diamantina formation (translated as “Diamantine Plateau”), and to the beautiful colouration of this species, composed of different shades resembling the effect caused by the reflection of light in diamonds. To be treated as a noun in apposition.

Material examined

Holotype BRAZIL • ♀; Bahia, Abaíra, Catolés district, near trail to Pico do Elefante; 13°16′11.2″ S, 41°54′22.2″ W; 1400–1500 m a.s.l.; 4 Mar. 2022; P.H. Martins, A. Galleti-Lima et al. leg.; Chapada Diamantina plateau, savannah in campo rupestre vegetation; MZUSP V0650 . GoogleMaps


Only two egg capsules and a single capitulum were obtained from inside the abdomen of the only known female and might differ in some details from laid eggs. The extracted capitulum appeared to be underdeveloped with only faint markings delimiting its ridges. For comparison, analysis of eggs of Arumatia dubia gen. et comb. nov. extracted from the same region of the abdomen revealed that in this species the capitulum and micropylar plate were already formed but the whitish dorsal stains were not present and the texture of the capsule was sometimes smooth, still not formed.


Female holotype (MZUSP V0650) MEASUREMENTS (in mm). Body (without cerci) 85.7, head 5.3, antennae at least 46.5, pronotum 3.5, mesonotum 20.0, metanotum 8.1, median segment 5.6, abdomen (excluding median segment) 43.2, cercus 3.5, profemur 20.2, protibia 20.9, mesofemur 15.5, mesotibia 15.7, metafemur 20.1, metatibia


COLOUR ( Figs 47–50 View Fig View Fig View Fig View Fig ). Entirely coloured of greyish to black, beige and brownish irregular stains with different shadings. Eyes grey. Mouthparts and cerci beige to light grey. Legs somewhat striped in darker and lighter patches.

HEAD ( Figs 47–48 View Fig View Fig ). Very elongate (2.3× as long as wide), smooth, with sparse setae mostly in dorsal region, vertex totally flat, frontal convexity developed and frontal suture round ( Fig.48A–B View Fig ). Eyes small, slightly elongate, slightly less than 0.2× length of head. Cervix covering more than two thirds of head length, cervical sclerites elongate, weakly sclerotized. Gula elongate, subrectangular, bearing setae and covering ca more than half of cervix ( Fig. 48D View Fig ). Subgena narrow, with posterior projection ca as high as eye. Submentum narrow, only slightly curved backwards, mentum simple, prementum somewhat wide. Glossa elongate, rounded but slightly widened apically, paraglossa larger than glossa, roundly falcate, reaching labrum ( Fig. 48C View Fig ). Lacinia with three distal teeth, one large medially and two smaller laterally, mesal edge bearing bundles of large setae from base to sclerotized portion. Galea broad, elliptical, medially gently widened, bearing long setae, apically with dense tuft of large, hairy microtrichia forming semicircular band along apical edge ( Fig. 48C View Fig ). Galealobulus present, small, round and basally fused to galea ( Fig. 48C View Fig ). Palpal segments slightly flattened dorsoventrally ( Fig. 48D View Fig ). Clypeus wide, somewhat short, anterior surface with two parasagittal furrows, anterior margin medially with smooth wide notch. Labrum strongly notched anteromedially, round and very slightly asymmetric with right lobe barely larger than left one. Antennae filiform, extending approximately to second abdominal segment and about as long as forelegs, scapus ca 2× as long as wide, compressed dorsoventrally. Pedicellus subglobose, large, more than half length of scapus, composed of 50–55 segments. Antennomeres bearing three types of setae as in A. dubia . Antennal bump very discrete on 12 th antennomere.

THORAX ( Figs 47 View Fig , 48A–B, D View Fig , 49A View Fig ). Smooth, with scarce scattered small setae. Pronotum slightly longer than wide, slightly constricted medially. Transverse sulcus conspicuous and gently curved backwards, longitudinal median sulcus distinct. Paranota curved, ca 3× as long as wide, with transversal projection ventrally, procoxopleurite apically round ( Fig. 48B View Fig ). Probasisternum tapering towards anterior. Profurcasternum round ( Fig. 48D View Fig ). Mesothorax 5.7 × as long as prothorax, slightly wider than it.

Mesonotum with pair of distinct lateral carinae, mesepisternum lanceolate and regularly widening posteriorly, mesepimeron slightly elongate, pointing towards posterior and slightly exceeding end of mesothorax. Mesocoxopleurite small, elongate, mesofurca Y-shaped. Metathorax continuing pair of lateral carinae of mesonotum, metepisternum long, similar to mesepisternum. Metepimeron extremely elongate, extending through entire length of median segment, posteriorly pointing and slightly exceeding end of median segment, metacoxopleurite very discrete and elongate, metafurca Y-shaped. Metanotum longer than median segment ( Fig. 49A View Fig ). Median segment anteriorly marked by median black stain ( Fig. 49A View Fig ) and barely continuing pair of thoracic lateral carinae.

LEGS ( Figs 47 View Fig , 49B–G View Fig ). Slightly thick for genus. Hindlegs slightly exceeding cerci, anterior legs very slightly shorter than hindlegs, midlegs distinctly shorter than both. Coxae smooth. Pro- and metafemora similar in length to mesothorax. Profemur with distinct basal curvature. Femora and tibiae with five keeled carinae with very few or without setae between them ( Fig. 49B–G View Fig ), basitarsi with setae among carinae. Antero- and posteroventral carinae of femora with apical toothed prominence. Carinae of all femora, tibiae and basitarsi bearing row of short and somewhat stout setae, stronger on tibiae and basitarsi, except ventral carinae of pro- and mesobasitarsi with two or three rows of setae. Ventral, antero- and posteroventral carinae of tibiae ending in apical spiniform sessile projection parallel to tibiae, pointing

towards tarsi; projection of protibiae weaker ( Fig. 49E–G View Fig ). Pro- and metabasitarsi very elongate, significantly longer than respective following tarsomeres combined, mesobasitarsi as long as respective following tarsomeres combined ( Fig. 49B–D View Fig ), basitarsi with hairy setae restricted to apical portion, on ventro-lateral patches ( Fig. 49B–D View Fig ). Remaining tarsomeres with setae on ventro-lateral patches in portions not covered by euplantulae. Tarsomeres I–III with discrete dorsal round apical projection. Arolium round and broad, bearing setae dorsally. Pretarsal claws symmetrical, dorsally and outwardly setose. Euplantulae well developed in all tarsomeres, composed of two symmetrical pads separated by median groove in tarsomeres I–IV and of single flattened lobed pad in tarsomeres V. Euplantulae present only apically at tarsomeres I–II, covering ca half length of tarsomeres III, covering two thirds length of tarsomeres IV and covering almost entire ventral surface of tarsomeres V ( Fig. 49B–D View Fig ).

ABDOMEN ( Figs 47 View Fig , 49A View Fig , 50 View Fig ). External surface as in thorax bearing few setae across entire length. Median segment ca 0.7× as long as metanotum ( Fig. 49A View Fig ). Combined length of segments II–X slightly longer than combined length of head, thorax and median segment. Terga II–VII and sterna II–VIII with discrete lateral carinae near lateral margins. All segments longer than wide ( Fig. 47 View Fig ). Segment II shorter than III–VII. Segments III, IV and VII similar in length, very slightly shorter than V, segment VI about as long as V. Tergum VIII significantly shorter than preceding segment and slightly longer than IX and X, tergum IX very slightly longer than X. Tergum II widest, slightly wider than III–IV, tergum V slightly wider than VI and wider than VII at medial width. Tergum VI dorsally with two large parasagittal rugose and somewhat round tubercles pointing towards lateral ( Figs 47 View Fig , 50A, E View Fig ). Tergum VII widening towards posterior, tergum VIII slightly narrower than preceding segment and tapering towards posterior, tergum IX narrower than VIII and X, tergum X slightly thinner than VIII, very gently tapering towards posterior, posterior margin broadly and gently emarginate ( Fig. 50B View Fig ). Epiproct very large, elongate, lanceolate, almost ⅔ length of tergum X, dorsoventrally flattened ( Fig. 50B–C View Fig ). Paraprocts very elongate, posteriorly tapering and very acute, straight, setose on posterior margin, reaching end of epiproct ( Fig. 50D View Fig ). Cerci extremely elongate, straight, basally slightly narrower fitting paraprocts, gradually tapering towards apex, slightly shorter than tergum X and epiproct combined ( Fig. 50A–D View Fig ) and bearing four types of setae similarly to A. dubia . Praeopercular organ present and very small, showing as small dark convexity ( Fig. 50F View Fig ). Subgenital plate roundly lanceolate, reaching ⅓ of length of tergum X, bearing two parasagittal carinae beginning on anterior margin and running half length of segment before becoming flatter and more setose, gradually tapering towards posterior and totally covering gonapophyses and gonoplac ( Fig. 50C–D View Fig ). Gonapophyses and gonoplac flattened, dorsoventrally for gonapophyses VIII, lateroventrally for gonapophyses IX and laterally for gonoplac. Gonapophyses VIII linear and elongate, longer than IX and gonoplac, exceeding posterior margin of tergum IX ( Fig. 50G View Fig ). Gonapophyses IX short, dorsally tapering towards posterior, shorter than gonoplac ( Fig. 50G View Fig ). Gonapophyses IX ventrally folded to fit within gonapophyses VIII. Gonangulum distinctly reduced. Gonoplac somewhat wide, lorate, not reaching posterior margin of tergum IX ( Fig. 50G View Fig ).

Egg ( Fig. 51 View Fig )

Egg not fully formed, retrieved from inside female holotype. Measurements in mm (N = 2): length 2.4– 2.6, height 1.7–1.8, width 1.4–1.5. Relatively small, ovoid in lateral view, not constricted at opercular

collar, gently compressed laterally, ca 1.8× as long as wide and 1.4× as long as tall ( Fig. 51A–C View Fig ). Capsule surface smooth but with finely punctuated appearance ( Fig. 51A View Fig ). Colour yellowish brown. Micropylar plate very elongate occupying a large area of the dorsal region, with round margins, almost parallel-sided ( Fig. 51B–C View Fig ). Micropylar cup small, rounded, only slightly elevated. Median line short and of same colour and elevation as elevated margin of micropylar plate, almost reaching polar area ( Fig. 51B–C View Fig ). Opercular collar very wide, as wide as surrounding capsule, smooth ( Fig. 51A–C View Fig ). Operculum elliptical, with branching radial ridges arising from central ridge along longer axis of operculum ( Fig. 51D View Fig ).

Distribution ( Fig. 52 View Fig )

Known only from the type locality, the Catolés district, Abaíra, Bahia, Brazil. Catolés is located in the Chapada Diamantina plateau which is the northern part of the Serra do Espinhaço formation that is typically dominated by campos rupestres. The Chapada Diamantina is mainly covered by the Caatinga but also has Cerrado patches ( Fig. 52 View Fig ). The holotype was found in a Cerrado area in dense savannic rocky formations (dense campos rupestres) ( Fig. 53I View Fig ).


Museu de Zoologia da Universidade de Sao Paulo