Astyliasula, Schwarz, Christian J. & Shcherbakov, Evgeny, 2017

Schwarz, Christian J. & Shcherbakov, Evgeny, 2017, Revision of Hestiasulini Giglio-Tos, 1915 stat. rev. (Insecta: Mantodea: Hymenopodidae) of Borneo, with description of new taxa and comments on the taxonomy of the tribe, Zootaxa 4291 (2), pp. 243-274 : 253-254

Genus Astyliasula gen. nov.

Type species: Mantis phyllopus De Haan, 1842 , present designation.

Diagnosis. Medium-sized to large Oxypilinae with strongly dilated femora and reduced styli. Head without median process. Juxta-ocular bulges small, widely rounded. Pronotum without paramedian spines. Maximum width of dilated part of fore femur at least 1.3 times maximum width of non-dilated part. Fore tibia slightly convex dorsally. Meso- and meta-femora with a ventral carina, sometimes slightly lamellar, but always without lobes. Male subgenital plate dorsally with sclerotized carinae on right side. Styli absent. Dorsal lamina of left phallomere strongly folded along median line. Oothecae large, often longer than the female’s body length, greenish, with very thick spongy mass surrounding the egg chambers.

Astyliasula gen. nov. can be distinguished from Pseudohestiasula gen. nov. by the absence of a process on the vertex and of the ventral lobe at the base of the meso femora, and also by the much more dilated fore femora, shorter fore leg spines, and the narrow, stick-like apical process. It differs from Hestiasula , Ephestiasula and Catestiasula by lacking a process on the vertex, styli, and the membraneous gap along the left edge of the ventral phallomere, by the small and widely rounded juxta-ocular bulges, and by possessing sclerotized carinae on the dorsal surface of subgenital plate, a sharply folded dorsal lamina of the left phallomere, and a narrow, stick-like apical process.

Description. Male. Medium-sized (body length 23–31 mm, forewing length 24–29 mm).

Head triangular , slightly wider than long. Vertex dorsally almost flat, sometimes with a pair of very shallow paramedian grooves, posterior margin highly compressed, more or less straight, much lower than imaginary line connecting the dorsal margin of the eyes. Juxta-ocular bulges widely rounded. Eyes ovoid, exophthalmic, ocelli large. Clypeus anteriorly with thin, low, median carina, sometimes faint, culminating in the central elevation. Scutellum pentagonal, wider than high. Antennae moniliform.

Prothorax short. Pronotum dorsally roughly rhomboidal, laterally triangular , narrowing anteriorly, in crosssection slightly compressed. Anterior edge widely rounded, lateral margin with a triangular tooth at widest point of pronotum, in metazona sharply bent dorsad, becoming unconnected with furcasternum. Posterior margin rounded or truncate. Prosternum flat, furcasternum longer than metazona of pronotum.

Fore coxae with small inclined spines on dorsal edge and numerous very short tubercles on ventral edge. Fore femora with extremely dilated, foliaceous dorsal margin, dilated part at least 1.3 times maximum width of ventral part. Ratio fore femur width/length at least 0.6. Dorsal edge of dilated part trapezoidal, dorsal edge of ventral part straight or very slightly sinuate. Ventral border of fore femur with 4 discoidal spines and 4 postero-ventral spines, in addition to 1 antero-ventral and 1 postero-ventral genicular spine; postero-ventral spine much larger than anteroventral one. Postero-ventral spines emerge from the cuticle flush with surrounding region. Postero-ventral margin slightly serrate between postero-ventral spines. Triangle formed by the two proximal-most postero-ventral spines and the distal-most discoidal spine small, sometimes with a shallow pit to accommodate distal-most postero-ventral spine of fore tibia. Claw groove near base. Fore tibia wide, dorsal margin convex, postero-ventral spines decumbent, with bases fused into a single plate. First tarsomere longer than remaining segments combined.

Mid and hind legs rather short. Femora with a ventral, sometimes slightly lamellar carina. Meso- and metatibiae simple, circular in cross-section. Hind metatarsus much shorter than remaining segments combined.

Wings macropterous, longer than abdomen, hyaline with or without dark pattern. Costal field at its widest point about 1/3 of tegmen width, stigma indistinct.

Abdomen moderately wide, without lobes. Tergites and sternites simple, rectangular, wider than long, with flat surface. Supra-anal plate trapezoid. Cerci very pilose, last segment conical. Subgenital plate sometimes asymmetrical, without styli, dorsally with sclerotized carinae on right side, ventrally covered by dense setae.

Genitalia heavily sclerotized, dorsal lamina of left phallomere strongly folded along median line.

Female. Like male, but slightly larger and more robust. Both pair of wings shortened, reaching at most slightly beyond supra-anal plate. Tegmina subopaque, costal field about 1/3 of tegmen width. Discoidal area of hind wings except the apex yellowish to brownish. Anal and jugal field, and apex of discoidal area strongly infumate with light veins. Abdomen widened, fusiform.

Etymology. The name is a combination of Greek prefix “α-“ meaning “not” or “absence of”, root “styli” and “- asula”, from Hestiasula .

Remarks. Aside from the two Bornean representatives treated here, H. basinigra , H. hoffmanni and H. wuyshana also fit the diagnosis of Astyliasula gen. nov. (see above), and are transferred here to this genus as A. basinigra ( Zhang, 1992) n. comb., A. hoffmanni ( Tinkham, 1937) n. comb., and A. wuyshana ( Yang & Wang, 1999) n. comb., respectively.

The subgenital plate of H. major (the genitalia of which have not been studied yet) is completely devoid of styli. Due to other morphological characters, like the lack of a process on the vertex, small and widely rounded juxta-ocular bulges, as well as the shape and color pattern of fore femora and wings we assign this species to Astyliasula as A. major ( Beier, 1929) n. comb.. Similarly, examination of the cotype of H. javana Beier, 1929 , due to the courtesy of Kai Schütte (ZMUH) and Gunvi Lindberg (NRM), revealead that this species also belongs to Astyliasula , and is to be referred to now as A. javana ( Beier, 1929) n. comb..

The females of H. inermis ( Wood-Mason, 1879) , as revealed by its original description, (see also Wood-Mason 1884), also perfectly fit the diagnosis of Astyliasula : there is no process on the vertex; the juxta-ocular bulges are smooth, widely rounded, almost flat; both pairs of wings are shortened, not reaching the apex of the abdomen; the discoidal field of hind wings is lemon-yellow, while the anal and jugal areas are dark brown with hyaline transverse veinlets. H. inermis is therefore transferred to this genus as A. inermis ( Wood-Mason, 1879) n. comb..

The distribution of Astyliasula gen. nov. comprises all of SE Asia from Assam and southern China to Borneo and Java .

Females of all species, which can be assigned to Astyliasula on morphological grounds, produce oothecae which are very large compared to the female’s body, covered by a very thick spongy mass, and of greenish color ( Shelford 1903, Beier, 1929, Zhu et al. 2012, R. Roy pers. comm., pers. obs. CS, Fig. 58 ), in contrast to the much smaller creamy-white oothecae of Ephestiasula and Hestiasula ( Ahmad et al. 1985, Heßler et al. 2008, McMonigle 2013). Such an unusual ootheca may be hypothesized as an autapomorphic developmental trait absent in other Hestiasulini known so far.

Figures

FIGURES 58 – 59. A. phyllopus. 58. Ootheca with hatching nymphs. 59. Displaying first instar nymph. Photos © Jürg Sommerhalder.