Hemiplasta flavifrons, Hennemann, 2021

Hennemann, Frank H., 2021, Stick insects of Sulawesi, Peleng and the Sula Islands, Indonesia- a review including checklists of species and descriptions of new taxa (Insecta: Phasmatodea), Zootaxa 5073 (1), pp. 1-189 : 130-132

Hemiplasta flavifrons n. sp.

( Fig. 51 )

HT, ♂: Eastern Central Sulawesi, Prov. Sulawesi Tengah , Banggai District, Luwuk , II.2007 [ MNHU, ex coll. FH, No. 0788-1]

Etymology: The name is a combination of the latin flavus (= yellow) and frons (= forehead) and refers to the distinctive bold yellow marking on the frons of ♂♂ of this new species ( Fig. 51C ).

Differential diagnosis: Males of this new species, the only sex known, are very similar to H. nigra ( Hennemann, 1998) n. comb. and H. mustea ( Bates, 1865) n. comb.. However, they readily differ from both species by the bold yellow marking on the frons between the bases of the antennae and the eyes ( Fig. 51C ) as well as the just weakly concave posterior margin of the anal segement (fig. 51D), which has the posterolateral angles somewhat more protruded and with more distinct denticles on their interior surface ( Fig. 51F ), and the club-shaped apex of the cerci. From the first they also differ by the dull green general colouration, green tegmina and costal region of the alae, which have the portion anterior to the radius orangey brown. The colour of the tegmina and costal region of the alae resembles H. mustea but from ♂♂ of this species they can be separated by the non-annulated limbs, which are plain brown with only the basal half of the femora green, and notably more abrasive and node-like granulae of the mesonotum ( Fig. 51C ).

Description: ♂ ( Figs. 51A–B ). Medium-sized (body length 54.8 mm), form fairly slender for the genus, with well developed alae (28.5 mm) that reach to abdominal segment VI, a densely granulose mesonotum and a distinctive yellow marking on the frons ( Fig. 51C ). General colour ochraceous brown, abdominal terga II–IX somewhat darker bown dorsally. Head with a bold, roughly circulur yellow marking on the frons between the bases of the antennae and the eyes, the genae with a very faint ochre postocular streak. Granules of mesothorax ochre. Tegmina mid green with the radius marked by a bright apple green streak and the partion anterior of the radius reddish mid brown. Costal region mid green with the portion anterior to the radius reddish mid brown; the anal fan hyaline with all major veins greyish brown. Legs generally reddish brown with the basal half of all femora green; the tibiae very faintly annulated with pale green. Antennae greyish mid brown and with a slight greenish wash towards the apex, scapus and pedicellus chestnut brown and antennomeres III and IV blackish and slighly glossy ventrally.

Head ( Fig. 51C ): Broad, subquadrate in dorsal aspect, broadest at the eyes with the vertex very gently convex and smooth; coronal line very weakly impressed. Frons with a shallow widely V-shaped impression and the yellow area between the eyes with two very low humps. No ocelli. Eyes very large, circular in out line, projecting hemispherically and their diameter conatined about 1.3x in length of genae. Scapus somewhat compressed dorsoventrally, pedicellus, round in cross-section, sub-spherical and notably shorter than scapus. Antennomere thickened basally. Antennae longer than body.

Thorax: Pronotum shorter and distinctly narrower than head, the anterior portion somewhat expanded and gently narrowing towards the posterior; surface sparsely and irregularly set with low granules ( Fig. 51C ). Median line impressed over entire length of segment and transverse median sulcus distint, very weakly arched and expanding entire width of segment. Mesothorax elongate, slender and somewhat constricted medially; 4.5x longer than pronotum ( Fig. 51C ). Mesonotum with a very fine and indistinct medio-longitudinal carina and all over covered with node-like granules ( Fig. 51C ), which however become slightly less pronounced and less numerous in the posterior portion; a granulose marginal carina close to lateral margins (a smooth lateral area present post-medially). Mesopleurae and meststernum sparsely and unevenly set with low granules, the sternum weakly tectinate longitudinally. Metapleurae and metasternum smooth. Tegmina roundly angular in shape with a very shallow and obtuse central hump. Alae reaching to posterior margin of abdominal segment VI.

Abdomen: Segment II slightly longer than median segment. II–IV very slightly increasing, V–VII decreasing in length; all uniform in width and longer than wide, VII shortest and less than ¾ the length of VI. Tergum VIII very gently widened towards the posterior and about 4/5 the length of VII. IX almost 1.3xc longer than IX, widest of all segments and increasing in height towards the posterior. Anal segment short, somewhat cucullate and less than half the length of preceding, the lateral surface somewhat convex and declining in lateral aspect ( Fig. 51D ); the posterior margin gently concave ( Fig. 51E ) and the outer angles protruded into and obtusely rounded swelling that has the intero-ventral surface set with several minute teeth. Epiproct very small, rounded and hardly visible in dorsal aspect ( Fig. 51E ). Vomer roughly triangular and with a short, up-curving terminal hook. Cerci long, slender, very gently in-curving and with the apex thickened and club-shaped; slightly longer than anal segment. Sternum IX bulgy and with the posterior margin very strongly expanded towards the posterior ( Fig. 51D ). Poculum cup-shaped, moderately convex, obtusely carinate longitudinally and narrowed towards the apex which is notched medially ( Fig. 51F ).

Legs: All long, slender and entirely unarmed. Profemora almost as long as head, pro- and mesothorax combined, metafemora reaching to posterior margin of abdominal segment IV and metatibiae projecting notably beyond tip of abdomen. Tarsi all long and slender with the basitarsi longer than the following three tarsomeres combined.

Comments: So far only known from the unique ♂ holotype. Female and egg unknown.

Distribution: Eastern Central Sulawesi, Prov. Sulawesi Tengah, Banggai District (Luwuk).

Figures

FIGURE 51. Hemiplasta flavifrons n. sp. ♂, holotype [MNHU]: A. Habitus, dorso-lateral view; B. Habitus, dorsal view; C. Head and prothorax seen dorso-laterally; D. Terminal abdominal segment in lateral aspect; E. Terminal abdominal segment in dorsal aspect; F. Terminal abdominal segment in ventral aspect.