Traiguma hamocauda, Dietrich & Nguyen & Pham, 2020

Dietrich, Christopher H., Nguyen, Huong T. T. & Pham, Hong Thai, 2020, New genera, new species and new records of leafhoppers (Hemiptera: Cicadellidae) from Vietnam, Zootaxa 4877 (2), pp. 241-273 : 263-265

Traiguma hamocauda n. sp.

( Figures 8 I–Q, 11W)

Description. Length of male 11.3 mm; female 15.5 mm. Overall coloration dark reddish brown with margins of most sclerites and venter somewhat lighter; setae clothing most body surfaces dark brown, pale along lateral mar- gin of pronotum and on tiny patches in inner and central anteapical cells of forewing; abdomen uniformly brown. Head with crown approximately three times longer than basal width between eyes; crown between eyes strongly depressed and concave; median longitudinal carina weakly elevated; ocelli elevated, situated slightly anteromesad of eyes. Anterior process nearly straight, extended anterodorsad, slightly broadened at midlength then slightly tapered toward obliquely rounded apex in lateral view, with single short tubercle preapically on each side; in dorsal view strongly constricted at midlength then widened to equal width between eyes near apex; dorsal surface deeply concave with large tubercle medially at base of broadened preapical area; apex diamond-shaped. Exposed part of mesonotum and scutellum together ~1.7X longer than pronotum, scutellum strongly convex and elevated above forewing base. Forewing apex subtruncate.

Hind femur macrosetal formula 2+1+1, preapical setae relatively small but stout; tibia rows PD, AD and AV with 14, 9 and 17 macrosetae, PV with numerous fine setae in basal three fourths and 4 macrosetae near apex; tarsomere I with two plantar rows of simple setae, pecten with 5 platellae.

Male pygofer incised to base dorsally, lobe in lateral view 1.5X longer than wide, apex obliquely truncate; ventral appendage stout, distal portion straight and parallel-sided in ventral view, apex terminating in sharp mesally directed spine. Style apophysis vestigial, short, rounded with few elongate setae. Connective narrow at base, broadened distally, anterior arms very short. Aedeagus simple, U-shaped, preatrium and dorsal apodeme short, shaft curved dorsad and tapered in lateral view to acute apex, with few indistinct denticuli on anterior surface and paired posterolateral ridges, in posterior view somewhat ovoid; gonopore large, preapical on posterior surface.

Etymology. The species name combines the Latin words “hamo” (hook) and “cauda” (tail), and refers to the hooked ventral appendages of the male pygofer.

Material examined. Holotype male, VIETNAM: Vinh Phuc, Tam Dao , 21.4509ºN 105.6325ºE, 741m, 13 July 2019, V . D. Nguyen, sweeping understory in 2º, pine forest, VN 19-8-2 ( VNMN). Paratype: 1 female, same data as holotype ( INHS). The type series was swept from small, broadleaved trees in the understory of a secondary pine forest .

Notes. Externally, the new species resembles the type species, T. nasuta Distant , in having the apical process of the head expanded distally but the new species is readily distinguished by the weakly elevated median longitudinal carina of the crown, the nearly uniform dark brown coloration of the dorsum, and the male genitalia. The three previously known species of the genus lack a ventral appendage on the male pygofer. Pygofer appendages are present in T. hamocauda and also occur in several other hylicine genera including Balala Distant , Hatigoria Distant , Kalasha Distant , Nacolus Jacobi and Sudra Distant , all of which differ from Traiguma in the structure of the head. The new species also differs from the genus description provided by Viraktamath & Webb (1991) in having different numbers of macrosetae on rows PD and AV of the hind tibia. Thus, placement of the new species in Traiguma must be considered tentative pending a thorough comparative analysis of the abovementioned genera. If the generic placement is correct, then the new species represents a considerable range extension for the genus, representing the first record outside the Indian subcontinent.

Figures

FIGURE 8. Iassinae and Hylicinae. A–H, Tardrabassus pakneunensis Dai & Dietrich, female: A–B, lateral and dorsal habitus; C, face and anterior part of thorax, ventral view; D, sternite VII, ventral view (left side damaged); E, gonoplacs; F–G, first valvula; H, second valvula. I–O, Traiguma hamocauda sp. n., holotype male: I–J, lateral and dorsal habitus; K–J, genital capsule, lateral ventral views; M, pygofer, ventral view; N, subgenital plates, ventral view; O–P, genitalia, ventral and lateral views; Q, aedeagus, posterior view.