Ellipsidion storozhenkoi Anisyutkin, 2025

Anisyutkin, Leonid N. & Telnov, Dmitry, 2025, A new species of the genus Ellipsidion Saussure, 1863 (Dictyoptera: Blattodea, Pseudophyllodromiidae) from the Papuan Region, Zootaxa 5715 (1), pp. 34-40 : 35-39

Ellipsidion storozhenkoi Anisyutkin , sp. nov.

( Figs 1–20 )

Type material. Holotype — ♂, E Indonesia: Raja Ampat archipelago, Waigeo Island, ~ 10 km NWW Waisai, 00°24’46’’S, 130°44’11’’E, 70–200 m, 19 February 2012, primary lowland rainforest on limestone, from a shrub, leg. D. Telnov.

Description. Male ( holotype). General appearance bright and contrasting ( Figs 1–4 ); facial part of head and vertex reddish-brown; eyes, clypeus, labrum, genal area and mouthparts blackish; weak blackish spots between and under antennal sockets ( Fig. 2 ); scape reddish-brown, with black proximal and distal ends; remaining antennomeres black except for pale antennomeres 50–55 ( Fig. 1 ), distal antennomeres brownish; 3rd and 4th maxillary palpomeres reddish-brown, with black anterior and posterior ends; median part of pronotum reddish, with few small black spots, lateral and posterior parts of pronotum yellowish and translucent ( Fig. 1 ); tegmina nearly translucent and brownish, slightly darkened apically and along posterior margin, veins in antero-proximal area bright yellow ( Fig. 1 ); wings translucent and yellowish, slightly darkened apically; legs brownish, with whitish apical parts of coxae and darkened tarsi ( Figs 1–4 ); abdomen black, with transverse white stripes along caudal margin of 2nd–7th abdominal sternites ( Fig. 2 ).

Surfaces smooth and lustrous; antennae, especially from 3rd to about 50th antennomeres, densely covered with chaetae.

Head slightly transverse (due to laterally strongly protruding eyes— Figs 2 , 5 ); ocellar spots absent; interocular distance nearly equal to eye length; distance between antennal sockets about 1.5 times scape length (~0.6 mm); approximate length ratio of 3rd–5th maxillary palpomeres 1.2: 1.0: 1.2. Pronotum as in Figs 1 , 6 , anterior margin barely concave, lateral—broadly rounded, posterior—slightly protruding. Tegmina and wings fully developed and functional ( Figs 1, 2 ), surpassing abdominal apex; tegmina weakly sclerotized, with distinct venation; wings membranous, apical triangle absent. Fore tibiae not thickened distally. Anterior margin of forefemur of armed type C 2, with only two apical spines. Tibial spines well developed. Structure of hind tarsus ( Figs 3, 4 ): metatarsus (1st segment) slightly shorter than remaining metatarsal segments combined, with small apical euplantula, and two subequal rows of spines along ventral margin; 2nd–4th tarsomeres with euplantulae rather large compared with respective tarsomeres, 1st–4th segments bordered with single “additional spine” on inside and outside; 2nd tarsomere with few spines along ventral margin; spines along ventral margins of 3rd and 4th tarsomeres absent; claws asymmetrical, anterior (outer) one shorter than posterior, simple; arolium large. Fore and mid legs similar in appearance to hind ones. Abdomen without visible glandular specializations. Anal plate (tergite X) subtriangular ( Fig. 7 ), with translucent membranous longitudinal stripe and distinct medial incision on caudal margin. Cerci slightly flattened, distinctly segmented, their distal parts broken off ( Fig. 7 ), only 8 and 7 segments present on left and right cercus, respectively. Paraprocts slightly asymmetrical ( Fig. 8 ), fused with anal plate, without armament (i.e. spines, teeth, etc). Hypandrium asymmetrical and elongated, narrowed distally ( Figs 9–12 ), right anterolateral process larger than left one; spicules on upper side of caudal margin disperse, not aggregate ( Fig. 10 , spi.); hind margin of hypandrium between styli deeply emarginate, with translucent membranous longitudinal stripe; cone-shaped outgrowth densely covered with small teeth located above right stylus ( Figs 10, 11 , r.out .); left stylus more or less globular, with apical acute and curved tooth and numerous smaller teeth on inner side; right stylus elongated and curved, narrowed distally, with numerous small apical teeth.

Male genitalia ( Figs 13–20 ). Right phallomere complex ( Figs 13–15 ): sclerite R1N large and elongated, located mostly on lower side of phallomere ( Figs 13, 14 , R 1N ); complex of R2 consists of several subsclerites; R3 of well sclerotized long U-shaped structure and slightly sclerotized plate between branches of U-shaped structure, “anterior protrusion” long and simple ( Figs 13–15 , a.p.), large “ventral sclerite” ( Figs 14, 15 , v.scl .) is perpendicular to phallomere. Sclerite L2D strongly sclerotized, not subdivided in to apical (caudal) and basal (cranial) parts, apically forked ( Figs 16, 17 ); basal part robust, moderately widened proximally ( Figs 16, 17 , b.L 2D ); left distal branch slightly curved, apically denticulate ( Figs 16, 17 , l.br.); right distal branch slightly curved ( Figs 16, 17 , r.br.), with flat spatula-shaped outgrowth at base ( Figs 16, 17 , s.out.) and membranous lobe ( Figs 16, 17 , m.lb.). Sclerite L4V complicated ( Fig. 18 ), with long curved whip-like basal outgrowth ( Figs 17, 18 , b.out.), apically bifurcated, with two “chaetae-bearing membranous areas” at apex ( Figs 17, 18 , c.b.m.a.). Sclerite L3 long and slender ( Figs 19, 20 ); hook hla slightly widened at apex, without groove hge. Sclerite L4U absent.

Measurements, male (mm). Head length: 2.4; maximum head width: 2.6; length of pronotum: 4.1; maximum width of pronotum: 5.7; tegmen length: 14.0; width of tegmen (at the point where CuP is running into posterior margin of tegmen): 4.5.

Diagnosis. The new species is most similar to E. castaneum ( Shelford, 1907) , but differs in following set of characters:

1) the central part of the pronotum is reddish, with small black spots compared to developed black spots in E. castaneum (compare fig. 1 and fig. 6A–D in Shelford 1908);

2) the hypandrium narrowed distally, without any outgrowths or processes along the caudal margin (except for cone-shaped outgrowth above right stylus), the medial incision deep and narrow, ending in a membranous stripe, a cone-shaped outgrowth is present above the right stylus (compare figs 9–12 and fig. 2A in Roth 1999).

Ellipsidion storozhenkoi sp. nov. differs from E. yapenensis Roth, 1999 in the coloration of the pronotum (compare fig. 1 and figs 5C–E in Roth 1999) and the medial incision of the hypandrium being deep and narrow, with a large and elongated right stylus (compare figs 9–12 and fig. 5F in Roth 1999).

The new species differs from other congeners in the shape of the sclerites L2D and L4V of the male genitalia and in the coloration of the head, pronotum and tegmina.

Etymology. Patronymic. The species is named after the famous entomologist Prof. Sergei Yu. Storozhenko (FSC Biodiversity FEB RAS, Vladivostok, Russia). Gender masculine.

Biology. Little is known of the biology of representatives of the genus Ellipsidion . According to Roach & Rentz (1998, p. 154–158) all known species of the genus are “volant, diurnal, aposematic, foliage frequenting” (cited after Roth 1999, p. 250). The specimen of the new species was collected from an upper part of a leaf of a young tree in a primary lowland rainforest close to a roadside in a hot and sunny daytime. The specimen was observed to be immobile, not changing its position on a leaf for some time.

Distribution. Raja Ampat archipelago, Waigeo Island.

Remarks. The asymmetry of the anal plate ( Fig. 7 ) is most likely due to a developmental disorder or damage of the larva.

Longitudinal transparent membranous stripes on the anal plate ( Fig. 7 ) and hypandrium ( Figs 9–12 ), if not carefully examined, can be mistaken for a deep incision.

In the male genitalia, large “ventral sclerite” ( Figs 14, 15 , v.scl .) is similar in position to “chaeta-bearing sclerite” of representatives of the genus Euphyllodromia Shelford, 1908 (see Anisyutkin 2011). However, it is premature to assume any homology of these structures, since such morphologically simple elements can obviously arise independently in different taxa.

Similarly, “anterior protrusion” of the right phallomere ( Figs 13–15 , a.p.) is present in representatives of Euphyllodromia ( Anisyutkin 2011) and Plectoptera Saussure, 1864 ( Anisyutkin 2009).

Figures

FIGURES 1–4. Ellipsidion storozhenkoi Anisyutkin, sp. nov., holotype, male; 1–2—habitus, dorsal (1) and ventral (2) view, caudal part of abdomen removed; right metatarsus laterally (below) (3) and ventrally (4). The arrow in Fig. 1 points to the pin that fixes the specimen.

FIGURES 5–12. Ellipsidion storozhenkoi Anisyutkin, sp. nov., holotype, male; 5—facial part of head; 6—dorsal outline of pronotum; 7—abdominal apex in dorsal view, apical parts of cerci broken off; 8—paraprocts in ventral view; 9—hypandrium in ventral view; 10–12—caudal margin of hypandrium in dorsal (10), caudal (11) and ventral (12) view. Membranous parts are depicted dotted. Abbreviations: r.out., spi.—see text. Scale bars = 1.0 mm: a = 5, 7, 9, b = 6, c = 8, d = 10–12.

FIGURES 13–20. Ellipsidion storozhenkoi Anisyutkin, sp. nov., holotype, male genitalia; 13–15—right phallomere in dorsal (13), ventral view (14) and inside (15); 16—sclerite L2D in dorsal view; 17—sclerites L2D and L4V in right lateral view; 18—sclerite L4V in ventral view, 19—sclerite L3; 20—apical portion of sclerite L3. Membranous parts are depicted dotted. Abbreviations: a.p., b.L2D, b.out., c.b.m.a., l.br., L4V, m.lb., r.br., R1N, R2, s.out., R3, v.scl.—see text. Scale bars = 1.0 mm: a = 13–15, b = 16–18, c = 19, 20.