Stalobrachys, Constant, 2018

Constant, Jérôme, 2018, Revision of the Eurybrachidae XIV. The Australian genera Olonia Stål, 1862 and Stalobrachys gen. nov. (Hemiptera: Fulgoromorpha), European Journal of Taxonomy 486, pp. 1-97 : 80-83

Genus Stalobrachys gen. nov.

urn:lsid:zoobank.org:act:7BB4E8DC-4BF9-4A5B-B653-76EC7BD66201

Figs 50–51

Type species

Olonia alboapicata Jacobi, 1928 , here designated.

Diagnosis

Rather small sized (8.5–10 mm), dark brown variegated with black and yellowish, tegmina with a white marking along costal margin on nodal line and posterior wings usually with a white marking near externoapical angle in males and with apex white in females. The genus can be recognized by the following set of characters:

(1) posterior wings with anal area well developed, broad (LW/BW = 1.5) ( Fig. 50A )

(2) posterior margin of pygofer with strongly developed projection at laterodorsal angle

(3) gonostyli moderately sclerified, separated and with elongate basodorsal process bearing dorsoapical, articulate, spoon-shaped process

(4) aedeagus reduced, with dorsal portion of phallobase bearing two convergent elongate spinose processes

The genus shares having a spoon-shaped process on the gonostyli with the Australian genera Chewobrachys Constant, 2008 , Fletcherobrachys Constant, 2006 , Hackerobrachys Constant, 2006 , Maeniana Metcalf, 1952 , Nirus Jacobi, 1928 and Olonia Stål, 1862 , but differs

– from Chewobrachys by the smaller size (8.5–10 mm; 12–16 mm in Chewobrachys ), the dark brown colour (greyish brown in Chewobrachys ) and the male gonostyli with an elongate basodorsal process (gonostyli without basodorsal process in Chewobrachys )

– from Fletcherobrachys by the bright red abdomen (green to orange in Fletcherobrachys ), the hind wings being brown with a (sub-)apical white marking (basal half white in Fletcherobrachys ), the absence of sexual dimorphism on the median tibiae (median tibiae with externodistal process in females of Fletcherobrachys ) and the male gonostyli separated and with an elongate basodorsal process (gonostyli fused along most of their length and without a basodorsal process in Fletcherobrachys )

– from Hackerobrachys by the frons being brown and slightly convex (bright yellow to red and strongly convex in Hackerobrachys ), the posterior wings being brown with a (sub-)apical white marking and rounded apically (uniformly brown with apex subquadrate in Hackerobrachys ) and the gonostyli being separated, with an elongate basodorsal process (gonostyli fused along most of their length and without a basodorsal process in Hackerobrachys )

– from Maeniana by the posterior wings having the anal area well developed (anal area of posterior wings reduced in Maeniana ) and showing a characteristic sexual dimorphism (no sexual dimorphism in the posterior wings in Maeniana )

– from Nirus by the frons being slightly convex (concave in Nirus ), the pygofer with the posterior margin strongly projecting posteriorly at dorsal ¾ (not projecting in Nirus ) and the gonostyli being separated and with an elongate basodorsal process (gonostyli fused and with a short basodorsal process in Nirus )

– from Olonia by the pygofer having the posterior margin with an elongate laterodorsal process projecting posteriorly (posterior margin only strongly sinuate in Olonia ), the gonostyli separated (fused along about ½ of their length in Olonia ) and the gonostyli having an elongate basodorsal process bearing a spoon-shaped process apically (spoon-shaped process attached to the lateral process of the laterodorsal part of the gonostylus, which bears a spine or hook, in Olonia )

The genus Loisobrachys Constant, 2008 is known from a single female and was placed by Constant (2008b) close to Hackerobrachys . Hence, the males of that genus potentially share having gonostyli with a spoon-shaped process. However, Stalobrachys gen. nov. can easily be separated from Loisobrachys by its slightly convex frons (frons strongly convex in Loisobrachys ) and by the posterior wings having white markings (uniformly brown in Loisobrachys ).

Etymology

The name of this genus is formed from ʻStalʼ in memory of the great contribution of the late Swedish entomologist Dr Carl Stål (1833–1878) to the study of Hemiptera , and brachys (Greek) = ʻshortʼ, which is a common ending of generic names in Eurybrachidae . Gender feminine.

Description

COLOURATION. Head, pro- and mesonotum, and tegmina brown, from pale brown to nearly black, usually variegated with darker and paler. Tegmina with yellowish marking in middle of clavus on vein A1; triangular white marking along costal magin on nodal line; smaller white marking at apicosutural angle. Posterior wings black-brown, darker from base to distal part; with white subtriangular marking at apicocostal angle in males and with apex largely white in females. Pro- and mesofemora and pro- and mesotibiae with 2 paler rings; metafemora reddish, turning to brown apically; metatibiae brown. Abdomen and ventral face of thorax bright red; genital segments brown with ventral part of gonostyli white in males; abdominal segment VII white in females.

HEAD. As broad as thorax; vertex 3.4–3.9 times as broad as long, concave, with all margins slightly carinate; anterior and posterior margins rounded, parallel; frons about 2.1 times as broad as long, slightly convex, slightly wrinkled to rugulose, with peridiscal carina slightly marked; upper margin of frons straight in normal view; clypeus slightly surpassing anterior trochanters, elongate, with median carina towards apex; labium reaching hind coxae, with apical segment longer than broad, acuminate, shorter and more slender than penultimate segment; no infra-ocular spines on genae; ocelli absent; antennae elongate, very slightly surpassing eye and visible from above; scape about as long as broad, pedicel elongate, barrel-shaped.

THORAX. About 1.55 times as broad as combined length of pro- and mesonotum; pronotum about half as long as mesonotum; pronotum with disc weakly wrinkled, smooth carina parallel to anterior margin and 2 slightly impressed points on disc; mesonotum with disc weakly wrinkled, median and peridiscal carinae slightly marked.

TEGMINA. Slightly convex; curving down at nodal line and with apex slightly curved upwards; elongate, about 2.15–2.5 times as long as broad; costal margin slightly sinuate; apical margin obliquely rounded; sutural margin slightly oblique after clavus. Venation: veins ScP+ RA and RP separated close to base; first fork of MP on basal ½; first fork of CuA slightly before apex of clavus; clavus closed; Pcu and A1 fused at ¾ of clavus length; Pcu +A1 reaching apical angle of clavus; numerous elongate cells along posterior half of costal margin and along apical margin.

POSTERIOR WINGS ( Fig. 50A ). Well developed, broader than tegmina, rounded apically; LW/BW = 1.5; anal area well developed; sutural margin very weakly trilobous; not reaching apex of tegmina at rest. All main veins visible from base, forked after nodal line and sometimes forming closed cells; transverse veinlets delimiting elongate cells on apical ½; vein A2 multiforked, with 2–4 terminals. Arrangement of secondary veins and veinlets variable between specimens and sometimes between the two wings of the same specimen ( Fig. 52A ).

LEGS. Pro- and mesofemora and -tibiae dorsoventrally flattened, elongate and slender; metatibiae with 3 lateral and 9 apical spines; first metatarsomere ventrally with pad of microsetae at interno-apical angle and group of 9 spines distributed more or less in two rows ( Fig. 50B ). Metatibiotarsal formula: (3) 9/4/0.

MALE GENITALIA. Pygofer rather short, higher than long and with basal margin sinuate in lateral view; in lateral view, dorsal portion narrower than ventral portion, and strong posterior projection at half heigth; aedeagus attached to apex of posterior process. Anal tube dorsoventrally flattened, elongate; epiproct at basal ½. Gonostyli separated, large, mostly dorsoventally flattened, and with an elongate basidorsal process directed dorsally and bearing spoon-shaped process apically. Aedeagus simple; phallobase with dorsal process elongate, projecting posteriorly and with apical part incurving, and ventral part elongate and dorsoventrally flattened; phallus membranous, dorsoventrally flattened and notched apically.

FEMALE TERMINALIA ( Fig. 51 ). Abdominal segment VI strongly narrowing apically, with posterior margin straight in ventral view and with a small posterolateral process projecting laterally ( Fig. 51C ); anal tube elongate and narrow, strongly curved posteroventrally before anal opening, v-shaped in cross section beyond anus, lanceolate in dorsal view ( Fig. 51A–B ); gonoplacs unilobed, projecting dorsolaterad, longer than high, not surpassing anal tube ( Fig. 51A–B ); gonapophysis IX large, elongate, apically rounded and curved dorsad ( Fig. 51A–B ); gonocoxae VIII looking like reniform inflated pouch ( Fig. 51A–B ); gonapophysis VIII dorsoventrally flattened and fused together, and with sternite VII in a large semicircular lobe transversely undulate and apically rounded ( Fig. 51A–C ).

SEXUAL DIMORPHISM. Females slightly larger than males. Colour dimorphism also affecting the colour pattern of posterior wings: males with a white spot at basicostal angle, females with apical margin largely bordered with white.

SIZE. ♂: 8.8 mm; ♀: 10.0 mm.

Distribution and biology

Australia: northern Queensland ( Fig. 3 ). Biology unknown.

Species included (1)

S. alboapicata ( Jacobi, 1928) gen. et comb. nov. (N Queensland)

Figures

Fig. 3. Olonia spp. and Stalobrachys alboapicata gen. et comb. nov. (Jacobi, 1928), distribution maps. A. Topographic map. B. Bioregion map.

Fig. 50. Stalobrachys gen. nov. A. Right posterior wing, venation. B. Right posterior leg, distal portion, ventral view. Abbreviations: A1 = first anal vein; A2 = second anal vein; CA = costa anterior; CuA = cubitus anterior; CuP = cubitus posterior; MP = media posterior; MtT1 = first metatarsomere; MtT2 = second metatarsomere; MtT3 = third metatarsomere; PCu = postcubitus; PMs = pad of microsetae; PT = posterior tibia; ScP+ R = subcosta posterior + radius; Sp = spines.

Fig. 51. Stalobrachys gen. nov., female genitalia. A. Dorsal view. B. Left lateral view. C. Ventral view. Abbreviations: An = anal tube; As V = fifth abdominal sternite; As VI = sixth abdominal sternite; As VII = seventh abdominal sternite; Gp = gonoplac; Gx VIII = gonocoxa VIII; Gy IX = gonapophysis IX.

Fig. 52. Stalobrachys alboapicata gen. et comb. nov. (Jacobi, 1928), holotype, ♀. A. Habitus, dorsal view. B. Habitus, ventral view. C. Habitus, normal view of frons. D. Labels.