Rustia Stål, 1866a

Marathe, Kiran, Sanborn, Allen F. & Kunte, Krushnamegh, 2018, Revision of the genus Rustia Stål, 1866 (Hemiptera: Cicadidae: Cicadinae) including a generic synonymy, four new combinations, and two new species from the Western Ghats, India, Zootaxa 4457 (3), pp. 431-443 : 432-434

Rustia Stål, 1866a

Rustia Stål 1866a: 8 .

Gudaba Distant 1906a: 138 . ( Burma) n. syn.

TYPE SPECIES. Cicada dentivitta Walker, 1862: 304 ( Siam) .

SPECIES INCLUDED. Rustia apicata ( Distant, 1906c) n. comb., Rustia dentivitta (Walker, 1862) , Rustia kodagura n. sp. , Rustia longicauda ( Lei, 1996) n. comb. , Rustia maculata ( Distant, 1912) n. comb. , Rustia marginata ( Distant, 1897) n. comb., Rustia minuta n. sp., and Rustia tigrina ( Distant, 1888) .

Remarks. Stål (1866a) described Rustia with the following characteristics (using current anatomical terminology): mesonotum width equal to the width of head, anterior margin of head between frons and rather prominent lobes of vertex deeply incised, lateral part of eyes hemispherical inclined upwards a small amount, postclypeus somewhat prominent; rostrum short; ocelli twice distance from eyes than from one another; hind wings with five apical areas. Distant (1905a) expanded the description of Rustia in the same work in which he established Gudaba . He described both Rustia and Gudaba possessing a head with eyes about as wide as the mesonotum and about as long as the pronotum, lateral pronotal margins nearly straight, abdomen longer than the distance between the apex of the head and base of the cruciform elevation, timbal covers shorter and narrower than timbal cavities, short male opercula not covering tympanal cavity, rostrum reaching posterior coxae, anterior femora strongly spined, fore wings and hind wings hyaline with eight and five apical cells, respectively ( Distant 1906a). Characters listed in one of the generic descriptions ( Distant, 1906a) that apply to both genera include the length of the head being about the distance between the eyes, the ocelli being closer to one another than to the eyes, lateral margins of the vertex not in line with those of the frons, the vertical angles globosely produced, eyes somewhat pedunculate, pronotum as long as mesonotum, the structure of the pronotal collar lateral angles and sinuate lateral margin of the pronotum, transverse male opercula, abdominal sternites III and IV in males with tubercles with the tubercle on sternite III being longest, and the fore wing basal cell being much longer than broad (see images in Fig. 5 ). The only character that is not obviously found in both genera is the lateral margins of the head being discontinuous found in the Rustia description ( Distant 1906a).

It is clear that the two genera share a common morphology and their status as separate genera is questionable. In addition to the shared characters from the original species descriptions, the genitalia are also highly similar. The pygofer distal shoulder is extended and wing-like curving laterad at its apex, and the uncus is broad at the base and tapering towards the apex. Distant (1906a; 1906b; 1914) used the 5 apical cells of the hind wings to distinguish Gudaba and Rustia from related genera. Distant's failure to recognize that Rustia possesses abdominal tubercles appears to be the reason for the erection of Gudaba . However, the presence of abdominal tubercles in Rustia was essential to the classification of the genus into their current subtribe ( Lee and Emery 2013). Therefore, without any significant general morphological features that appear to be unique in the two genera, we recognize Gudaba Distant, 1906 n. syn. as a junior synonym of Rustia Stål, 1866a . As a result of this synonymy, the species previously assigned to Gudaba become Rustia apicata ( Distant, 1906c) n. comb. , Rustia longicauda ( Lei, 1996) n. comb. , Rustia maculata ( Distant, 1912) n. comb., and Rustia marginata ( Distant, 1897) n. comb.

Description. Body size small (8–17mm body length), female shorter than male due to the male's elongated abdomen. Head about as wide as mesonotum and as long as distance between eyes, eyes protruding beyond anterior pronotal margin with a slight dorsal incline, somewhat pedunculate, ocelli closer to one another than to eyes; vertex at area of ocelli about as long as front, with a deep depression lateral to lateral ocelli and globosely produced anterolateral margins; postclypeus rounded in transverse section, lacking central sulcus, rostrum length varying among species but extended to some point between middle trochanters and abdominal sternite I. Pronotum as long as mesonotum, trapezoidal with anterior margin narrower than lateral margins of pronotal collar, lateral angles of pronotal collar slightly expanded, lateral margins of pronotal collar confluent with adjoining pronotal sclerites, sinusoidal when viewed from dorsal side. Dorsal midline of metanotum entirely concealed. Fore wing and hind wing hyaline, with eight and five apical cells, respectively, with various patterns of infuscation on apex, radial and radiomedial crossveins, distal marginal cells and ambient vein of fore wing, radial and radiomedial crossveins generally not parallel. Basal cell longer than broad and unmarked. Basal area of fore wing clavus and hind wing costal cell without infuscation. Fore wing cubitus posterior and anal vein 1 fused in part, median vein and cubitus anterior separated when meeting the basal cell, hind wing radius posterior and median veins fused at their bases, cubitus posterior and anal vein 1 unfused, and distal end of anal vein 3 straight. Fore femur with oblique primary spine, upright or less oblique secondary spine, possibly with very small apical spine, tarsi three-segmented. Male operculum small, scale-like, not covering tympanal cavity or encapsulating meracanthus, opercula well separated along midline, meracanthus tapering to a point, reaching to or past posterior margin of operculum. Abdomen longer than the distance between the apex of head and cruciform elevation in males but about the same distance in females, timbal cover small, recurved laterally forming a flattened ridge on the posterior timbal cavity, timbals extend below wing bases, abdominal segments with parallel sides to segment 8 where they narrow posteriorly to the genitalia, sternites III and IV with tubercles on posterolateral surface, the tubercle on sternite III longer. Pygofer distal shoulder well developed extending into a point or wing-like structure that is curved laterad, dorsal beak absent, pygofer upper lobe small, adpressed to lateral pygofer, pygofer basal lobes absent, uncus well developed with broad base and tapering towards apex, uncus retractable within pygofer, claspers absent, and male aedeagus simple, restrained under uncus. Female abdominal segment 9 with dorsal beak well defined and sinuate posterior margin, ovipositor sheath extends to about the level of the dorsal beak. Female sternite VII with medial notch.

Measurments (MM). Length of body: 8.3–17.0; length of fore wing: 13.1–22.4; width of fore wing: 4.5–7.2; length of head: 0.6–1.8; width of head including eyes: 3.2–5.2; width of pronotum including suprahumeral plates: 3.6–5.2; width of mesonotum: 3.0–4.7. Female body length is generally less than in males due to the longer male abdomen.

Diagnosis. The diagnostic features for members of the subtribe as described by Lee and Emery (2013) will distinguish what is now the only genus of the subtribe from all other members of the tribe. All other Leptopsaltriini have six apical cells in the hind wing.

Distribution. The genus in its new concept is found over much of Southeastern Asia including Borneo, Burma, Cambodia, China, Himalayas, India, Indonesia, Korea, Nepal, Philippine Republic, Thailand, and Vietnam ( Metcalf 1963; Sanborn 2013; 2015; Price et al. 2016). It has yet to be recorded from Laos ( Lee 2014).

Figures

FIGURE 5. A comparison of all the know members of Rustia genus. (A) Rustia dentivitta (Walker, 1862), (B) Rustia tigrina (Distant, 1888), (C) Rustia marginata (Distant, 1897) n. comb., (D) Rustia maculata (Distant, 1912) n. comb., (E) Rustia apicata (Distant, 1906c) n. comb., (F) Rustia longicauda (Lei, 1996) n. comb., (G) Rustia minuta n. sp., and (H) Rustia kodagura n. sp.