Arumatia crassicercata Ghirotto, Crispino & Engelking, 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 : 34-42

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Arumatia crassicercata Ghirotto, Crispino & Engelking

gen. et sp. nov.

Arumatia crassicercata Ghirotto, Crispino & Engelking gen. et sp. nov.

Figs 19–24 View Fig View Fig View Fig View Fig View Fig View Fig , 52 View Fig , 53E View Fig



From Arumatia fulgens gen. et comb. nov. it differs by the thicker and prominently keeled legs, the shorter median segment, the slightly shorter subgenital plate, the shorter and thicker cerci, the presence of a praeopercular organ, the lack of a black dorsal line and the thinner body. From A. anyami gen. et sp. nov. it differs by the lack of a conspicuous black spot on the ventral region of the prothorax, slightly shorter subgenital plate, smaller epiproct, shorter cerci, the posterior margin of anal segment less emarginate, the presence of a praeopercular organ and shorter gonapophyses VIII and IX. Some mouthparts differ between the two species, as A. crassicercata gen. et sp. nov. has a narrower galea and narrower labial palp segments than those of A. anyami . From A. dubia gen. et comb. nov. it differs by the presence of a praeopercular organ, a shorter median segment, shorter and thicker cerci and thicker legs with more prominent keels. Arumatia crassicercata also has slightly more setae on the lacinia than A. dubia , and the microtrichia on the galea are arranged in a shorter patch and forming a circle, not a band. From A. aramatia gen. et sp. nov. it differs by the shorter, less elongate head, the more elongate galea, the longer median segment in relation to the metanotum, the emarginate posterior margin of tergum X, the shorter and thicker cerci, and the shorter gonapophyses IX. From A. motenata gen. et sp. nov. and A. diamante gen. et sp. nov. it differs by the shorter, less elongate head, the longer median segment as long as the metanotum, the presence of stronger spiniform setae on the carinae of the tarsi and on the apex of mid and hind tibiae, the absence of an apical sessile spine on the apex of ventral, antero- and posteroventral carinae of tibiae, the shorter and thicker cerci and the shorter epiproct, the longer subgenital plate, the narrower gonoplac and the shorter gonapophyses VIII and IX.


The egg of Arumatia crassicercata gen. et sp. nov. has a smoother capsule than that of A. anyami gen. et sp. nov., shown as a finely punctuated texture, a more parallel-sided posteriormost region of the micropylar plate, and a micropylar plate more convex in lateral view than that of A. dubia gen. et comb. nov., a netted rather than radial capitulum present on the egg of A. aramatia gen. et sp. nov.,

A. motenata gen. et sp. nov. and A. diamante gen. et sp. nov., additionally to the more expanded whitish stain around the micropylar plate than that of A. motenata , from the polar region to the opercular collar.


This species is named after its thick and untapering cerci, which readily differentiate it from other species of the genus. The name is an adjective derived from the Latin words ‘ crassus ’ (= ‘thick’) and ‘ cercus ’.

Material examined

Holotype BRAZIL • ♀; Goiânia, Chapada dos Veadeiros, Alto Paraíso de Goiás , Trilha da Cachoeira do Segredo ; 14°15′37″ S, 47°52′11″ W; 31 Dec. 2016 – 1 Jan. 2017; P.I. Chiquetto-Machado and A.Z. Ramin leg.; MZUSP 0812 View Materials . GoogleMaps

Paratypes BRAZIL • 3 ♀♀; same collection data as for holotype; MZUSP 0813 View Materials , 0814 View Materials , 0871 View Materials GoogleMaps eggs; same collection data as for holotype; MZUSP GoogleMaps .


Female (holotype, MZUSP 0812)

MEASUREMENTS (in mm). Body (without cerci) 66.65, head 3.75, antennae at least 38, pronotum 2.1, mesonotum 16.1, metanotum 6.0, median segment 3.7, abdomen (excluding median segment) 33.0, cercus 2.25, profemur 4.1, protibia 16.8, mesofemur 9.9, mesotibia 10.0, metafemur 12.1, metatibia 14.2.

COLOUR ( Figs 19–20 View Fig View Fig ). Entirely green. Eyes yellowish to brown. Antennae darker ventrally. Apical segments of palp and other mouthparts brownish to beige.

HEAD ( Fig. 21 View Fig ). Somewhat elongate, slightly bulky, smooth and with sparse setae mostly on dorsal region. Vertex flat but gently convex at posterior margin to fit underneath the pronotum, frontal convexity developed and frontal suture pyramidal ( Fig. 21A–B View Fig ). Eyes small and slightly elongate, approximately 0.17 × as long as head ( Fig. 21B View Fig ). Cervix covering more than half length of head, cervical sclerites weakly sclerotized, gula somewhat spatulate, bearing setae and covering ca more than half of cervix ( Fig. 21C View Fig ). Subgena narrow with posterior projection ca height of middle of eye. Submentum narrow, only slightly curved backwards, mentum simple, prementum somewhat wide ( Fig. 21C View Fig ). Glossa elongate, rounded, paraglossa larger, roundly falcate, almost reaching labrum. Lacinia with three distal teeth, one large medially and two smaller laterally, with mesal edge bearing bundles of ca 22 large setae from base to sclerotized portion ( Fig. 21D View Fig ). Lobe over base of lacinia almost indistinct. Galea elliptical and bearing long setae, apically with dense tuft of hairy, large microtrichia in round shape, dorsally and posteriad to this patch ca 25 distinct circular granules of same diameter as setae base ( Fig. 21D View Fig ). Galealobulus present, widely round but gently protruding and basally fused to galea ( Fig. 21D View Fig ). Palpal segments cylindrical. Clypeus wide. Labrum strongly notched anteromedially. Antennae filiform, composed of at least 45 segments exceeding posterior margin of median segment ( Fig. 21A–B View Fig ). Scapus longer than wide, basally constricted in dorsal view, slightly compressed dorsoventrally, pedicellus subglobose and more than half length of scapus. Antennal bump very discrete dorsally on posterior region of 12 th antennomere.

THORAX ( Figs 19–20 View Fig View Fig , 21A–C View Fig , 22A View Fig ). Smooth with scattered setae. Pronotum very slightly longer than wide and slightly constricted pre-medially, fairly flat in lateral view, transverse sulcus conspicuous and

gently curved, longitudinal median sulcus distinct. Paranota curved, medially constricted, ca 3 × as long as wide, procoxopleurite apically round ( Fig. 21A–B View Fig ). Probasisternum tapering towards anterior with two round apices on anterior margin, profurcasternum round ( Fig. 21C View Fig ). Mesothorax 6–7× as long as prothorax, as wide as prothorax anteriorly and slightly widening towards posterior region ( Fig. 19 View Fig ). 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 indistinct, mesofurca Y-shaped ( Fig. 19 View Fig ). Metathorax continuing pair of lateral carinae of mesonotum, metepisternum long, similar to mesepisternum, metepimeron extremely elongate, extending across entire length of median segment, posteriorly pointing and slightly exceeding posterior margin of median segment ( Fig. 22A View Fig ). Metacoxopleurite very discrete, elongate, metafurca Y-shaped ( Fig. 19 View Fig ). Metanotum 1.6× as long as median segment ( Fig. 22A View Fig ). Median segment anteriorly marked by two small ovoid parasagittal stains. Posterior margin of metanotum and anterior margin of median segment slightly widened ( Fig. 20 View Fig ).

LEGS ( Figs 20 View Fig , 22 View Fig ). Slender. Hindlegs not extending beyond apex of abdomen, slightly longer than forelegs, midlegs distinctly shorter. Coxae smooth ( Fig. 21A–C View Fig ). Profemora ca as long as mesothorax,

mesofemora about 0.6× as long as profemora, metafemora shorter than mesothorax. Protibia slightly longer than profemur, mesotibia barely longer than mesofemur, metatibia slightly longer than metafemur. Profemur with distinct basal curvature ( Figs 19–20 View Fig View Fig , 21A–B View Fig ). Femora and tibiae with five carinae without setae among them ( Fig. 22B–E View Fig ). Carinae of femora and tibiae prominently keeled ( Figs 19–21 View Fig View Fig View Fig ). Antero- and posteroventral carinae of femora with round apical prominence. Carinae of all femora, tibiae and tarsi bearing row of short, somewhat stout setae, last two to three setae of all five carinae of meso- and metatibiae thicker and spiniform ( Fig. 22B–E View Fig ).In tarsi, setae present on ventral, antero- and posteroventral carinae distributed across entire length but apex. Tarsi setae on all carinae of probasitarsi short. Tarsi setae present on ventral, antero- and posteroventral carinae of meso- and metabasitarsi stouter while on mesobasitarsi, setae stronger and spiniform on these same carinae. All basitarsi very elongate, pro- and metabasitarsi significantly longer than respective following tarsomeres combined, mesobasitarsi as long as following tarsomeres combined ( Fig. 22B–E View Fig ), with setae restricted to apical portion on ventrolateral patches. Remaining tarsomeres with setae on ventro-lateral patches in portions not covered by euplantulae. Arolium round and broad, bearing setae dorsally. Pretarsal claws symmetrical, dorsally and outwardly bearing setae. Euplantulae well developed in all tarsomeres, composed of two symmetrical pads separated by median groove in tarsomeres I–III, of single pointing domed pad in tarsomeres IV and of single flattened lobed pad in tarsomeres V. Euplantulae present only apically on 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. 22B, C, E View Fig ).

ABDOMEN ( Figs 19–20 View Fig View Fig , 23 View Fig ). External surface as in thorax bearing few setae across entire length. Median segment shorter than metanotum ( Fig. 22A 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 bearing discrete lateral carinae near lateral margins. All segments longer than wide ( Figs 19–20 View Fig View Fig ). Segment II as long as VII and slightly shorter than III, segments III and IV of ca same length, IV slightly shorter than V, V and VI of ca same length, tergum VIII significantly shorter than preceding segment, and barely longer than IX, tergum X slightly longer than IX and ca as long as VIII. Lateral borders of tergum

VII gently curving downwards and inwards near posterior margin. Tergum X dorsally just slightly narrower towards apex, with posterior margin gently emarginate ( Fig. 23A View Fig ). Epiproct barely visible, wide and short. Paraprocts elongate, posteriorly acute, straight, bearing setae on posterior margin. Cerci elongate, straight, pointing to posterior, cylindrical, tapering near apex and slightly longer than tergum X ( Fig. 23A–C View Fig ). Praeopercular organ small, elliptical with longitudinal keel, anteriorly with small yellow convex rugosity, slightly away from posterior margin of sternum VII and only slightly prominent in lateral view ( Fig. 23B–D View Fig ). Subgenital plate lanceolate, acute, almost reaching posterior margin of tergum X, bearing median and 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. 23B–C View Fig ). Gonapophyses and gonoplac flattened, dorsoventrally for gonapophyses VIII, lateroventrally for IX and laterally for gonoplac ( Fig. 23B View Fig ). Gonapophyses VIII longer than IX, slightly exceeding posterior margin of tergum IX, gonapophyses IX reaching about ¾ length of tergum IX, gonapophyses VIII elongate, somewhat falcate, slightly sinuous, tapering towards posterior and gonapophyses IX conical, short and abruptly tapering towards posterior ( Fig. 23E View Fig ). Gonapophyses IX ventrally folded to fit within gonapophyses VIII. Gonangulum distinctly reduced and flat ( Fig. 23E View Fig ). Gonoplac elongate and lorate, bearing setae, exceeding both gonapophyses and posterior margin of tergum IX ( Fig. 23E View Fig ).

Egg ( Fig. 24 View Fig )

Measurements in mm (N = 10): length 2.4–2.5, height 1.7–1.8, width 1.3–1.4. Relatively small, capsule ovoid, constricted at the opercular collar and taller at the region of micropylar plate, laterally compressed and ca 2 × as long as wide and 1.5 × as long as tall ( Fig. 24A–C, E View Fig ). Capsule surface smooth but with finely punctuated appearance. Colour varying in shades of orangish or reddish brown with creamy, lighter band on dorsal, anterior and posterior regions, surrounding operculum and polar region ( Fig. 24 View Fig ). Micropylar plate convex, very elongate, occupying large area of dorsal region, elliptical with round apical margins and almost parallel sides with posteriormost portion not widened or just very slightly widened

( Fig. 24B–C, E View Fig ). Micropylar plate with lighter elevated outer circle delimiting darker inner flat region confluent with micropylar cup ( Fig. 24B–C View Fig ). Micropylar cup small, rounded and only slightly elevated, dark. Median line short, in same colour and elevation as elevated margin of micropylar plate and almost reaching polar area ( Fig. 24B–C View Fig ). Opercular collar narrower (constricted) than rest of capsule, smooth, whitish and with minute and delicate bristles surrounding edge ( Fig. 24B–D View Fig ). Operculum elliptical, with irregular, somewhat radial to reticular, sinuous elevations of amber texture composing non-stalked capitulum ( Fig. 24B, D View Fig ).

Distribution ( Fig. 52 View Fig )

Known only from the type locality. The types were collected at the margins of a river in a gallery forest ( Fig. 53E View Fig ) of the Cerrado domain, in the Central-West region of Brazil, in the Chapada dos Veadeiros plateau, municipality of Alto Paraíso de Goiás, Goiás State, Brazil.


Museu de Zoologia da Universidade de Sao Paulo