Placoblatta semialata, Anisyutkin, 2020

Anisyutkin, Leonid N., 2020, New and little known Epilamprinae (Dictyoptera: Blaberidae) from the collections of the Muséum d’histoire naturelle de Genève and the Zoological Institute of Saint Petersburg. Part 4, Revue suisse de Zoologie 127 (1), pp. 105-117 : 106-108

Placoblatta semialata sp. nov.

Figs 1-20

Etymology: The species name, an adjective, is derived from the Latin words “semi-” (= half) and “alatus” (= winged) and refers to the structure of the male tegmina.

Material examined: MHNG (sample (INDO-13/14, GPS25 ); male holotype; Indonesia, Sulawesi Tengah, Luwuk Utara Regency, Salodik District , road Luwuk-Gua Bolo Poniki , 00°50’27.0”S, 122°52’31.7”E, 416 m, highland primary forest on limestone , sifting; 12.IV.2013; C. Rahmadi & L. Monod leg., permit 88/ SIP/FRP/SM/ III/2013 . – MHNG; 1 female, 1 larva, paratypes; same data as for holotype . – MHNG (sample INDO-13/15, GPS26 ); 1 male; Sulawesi, Luwuk Barat Regency, Nambo Bosa District, mountains north of Nambo Bosa , 01°02’11.5”S, 122°41’11.4”E, 607 m, highland primary forest on limestone , night collecting, on tree trunks, under logs and in rock crevices; 13.IV.2013; C. Rahmadi & L. Monod leg., permit 88/ SIP/FRP/SM/ III/2013.

Diagnosis: The new species can be readily distinguished from all other representatives of the genus by its large tegmina which reach the 2nd abdominal tergite. Additionally, P. semialata sp. nov. differs from other species of the genus in the following characters: (1) from P. rugosa in smaller size, smaller apical euplantula of hind metatarsus (this euplantula occupying more than half of hind metatarsus length in P. rugosa , Figs 4-5 , cf. Anisyutkin, 1999: fig. 58) and in a long and slender sclerite L3 of the male genitalia (this sclerite short and robust in P. rugosa , Fig. 18 , cf. Anisyutkin, 1999: figs 65-66); (2) from P. beybienkoi in the presence of a well developed rows of spines on the hind metatarsus (tarsal spines absent in P. beybienkoi , Figs 4-5 , cf. Anisyutkin & Yushkova, 2017: fig. 7C); (3) from P. minor in a flat “dorsal outgrowth” of sclerite L2D of the male genitalia (“dorsal outgrowth” ridge-like in P. minor , Figs 16-17 , cf. Anisyutkin, 2018b: figs 16-21).

Description of male holotype: General colour yellowish, with scattered brown spots ( Figs 1-3 ); facial part of head mostly yellow ( Fig. 1 ); eyes black; antennae with scapus and pedicellum yellowish brown, following approximately ten segments yellow, remaining segments brownish; mouthparts and part of legs yellow ( Figs 3-5 ). Surfaces lustrous; antennae with lustrous proximal 11-12 segments, other segments dull; pronotum densely covered with small tubercles, especially in central part; abdominal tergites with rows of tubercles along caudal margin ( Fig. 2 ); facial part of head with weak punctuation. Head longer than wide, epicranial sutures distinct ( Fig. 1 ); ocellar spots small, weakly expressed; distinct transverse furrow located between antennal sockets; distance between eyes about 0.8 times eye length; distance between antennal sockets about 1.7 of scape length (about 0.8 mm); approximate ratio of lengths of 3rd to 5th segments of maxillary palps 1.1: 1.0: 1.2. Pronotum campaniform, much wider than long, anterior and lateral margins semicircular, posterior margin very weakly protruded caudally ( Fig. 2 ). Meso- and metanotum much wider than long, covered with tegmina ( Fig. 2 ). Tegmina in shape of parallelogram ( Fig. 2 ), reaching 2nd abdominal tergite, venation visible but reduced. Anterior margin of fore femur of type B armament, with 6 spines, apical spines absent ( Fig. 3 ). Fore tibiae not thickened distally ( Fig. 3 ). Structure of hind tarsi ( Figs 4-5 ): metatarsus a little shorter than other segments combined, with small apical euplantula and two more or less equal rows of spines along lower margin; euplantulae of 2nd to 4th segments large; all euplantulae bordered with 2-3 additional spines ( Figs 4-5 , a.s.) and without spinules; claws symmetrical and simple; arolium about half of claw length. Fore and mid tarsi similar to hind tarsi, but segments comparatively shorter. Abdominal tergites without visible glandular specializations; posterolateral angles of tergites attenuate and sharp. Anal plate (tergite X) wide, caudal margin widely rounded, with distinct median incision ( Fig. 10 ). Cerci shortened and flattened, with segments partly fused ( Figs 10-11 ). Paraprocts of blaberid-type ( Fig. 12 ). Hypandrium nearly symmetrical ( Fig. 13 ), its caudal margin rounded, with a distinct median incision; styli symmetrical and fusiform.

Genitalia ( Figs 14-20 ). Right phallomere (R+N) with caudal part of sclerite R1T subrectangular in shape ( Figs 13-14 , c.p.R 1T ), densely covered with bristles; R2 distinctly curved; R3 elongated; R4 plate-like; R5 large, fused with sclerite R3. Sclerite L2D (L1) divided into basal and apical parts ( Fig. 16 ); basal part rod-like; apical part rounded, densely covered with recumbent bristles; “dorsal outgrows” flat ( Figs 16-17 , d.o.). Sclerite L3 (L2d) with basal subsclerite ( Fig. 18 , b.L 3 ) and weak “folded structure”, bristles absent; apex of L3 with “small tooth” ( Figs 19-20 , s.t.); groove hge absent. Sclerite L4U (L3d) small and elongated, weakly sclerotized.

Variation in males: Male paratype similar to holotype, but slightly smaller.

Description of female paratype: Similar to males, but different in the following characters. General colour slightly darker ( Figs 6-8 ), facial part of head brownish. Distance between eyes about equal to eye length; distance between antennal sockets about 1.6 of scape length (about 0.8 mm). Tegmina and wings completely absent. Anterior margin of fore femur with 5-6 spines, 1 apical spine present on left femora. Abdominal apex as in Figs 7-8 . Genital plate wide, caudally rounded ( Fig. 8 ).

Description of larva paratype: Similar to adult female, but smaller and lighter in colour.

Measurements (in mm; measurements in parenthesis are those of holotype): Head length: male 2.9-3.0 (3.0), female 2.8; head width: male 2.5-2.7 (2.7), female 2.6; pronotum length: male 5.0 (5.0), female 4.5; pronotum width: male 8.3-8.4 (8.4), female 8.1; tegmen length: male 4.8-5.0 (4.8); tegmen width: male 4.3-4.7 (4.7).

Figures

Figs 1-8. Placoblatta semialata sp. nov., male holotype (1-5) and female paratype (6-8). (1) Facial part of head. (2, 6) Anterior part of body, dorsal view. (3) Right fore leg, ventral view. (4, 5) Right hind tarsus, ventral (4) and outer (5) view. (7-8) Abdominal apex, dorsal (7) and ventral (8) view.The black parallelogram in Fig.5 is a pin.Abbreviations: a.s. - see chapter “abbreviation used in figures”, for details see text. Not to scale.

Figs 9-20. Placoblatta semialata sp. nov., male holotype. (9) Facial part of head. (10) Abdominal apex, dorsal view. (11) Left cercus, dorsal view. (12) Paraprocts, ventral view. (13) Hypandrium, ventral view. (14-15) Right phallomere, ventral (14) and dorsal (15) view. (16) Sclerite L2D, dorsal view. (17) Apical part of sclerite L2D, dorsal view. (18) Sclerite L3. (19-20) Apex of sclerite L3. Dotted areas show membranous parts. Bristles are not shown in Fig. 16. Abbreviations: b.L3, c.p.R1T, d.o., R2, R3, R4, R5, s.t. - see chapter “abbreviation used in figures”, for details see text. Scale bars 1 mm: a (9), b (10-13), c (14-15, 17), d (16, 18), e (19-20).