Rhabdoblattella alexeevi Anisyutkin, sp.nov.
Creators: name: Anisyutkin, Leonid N.
name: Yushkova, Olga V.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Blattodea
Blaberidae
Rhabdoblattella
Rhabdoblattella alexeevi

description: Rhabdoblattella alexeevi Anisyutkin, sp.nov.
(Figs. 4A–C, 5 A–N)
Material. Holotype—male, SOUTH INDIA, state Kerala, Cardamon Hills, Muttapatti near Munnar, 1700 m, sieving in forest at the foot of a group of tree ferns, 22 November 1972, coll. C. Besuchet / I. Löbl (48) (MHNG).
Etymology. This species is named in honour of the late Prof. Dr. Andrey N. Alexeev (1930–2015), a famous parasitologist and a true Russian intellectual, under whose supervision the authors of the present paper had a pleasure to work.
Description. Male (the holotype). General colour reddish brown (Fig. 4A–C); facial part of head brown; eyes black; pronotum, tegmina and abdomen densely speckled, with small dark maculae; legs dirty yellowish. Surfaces smooth and lustrous. Head convex (Figs. 4C, 5 A); epicranial sutures present; ocellar spots small, but distinct; weak transverse hollow located between antennal sockets; distance between eyes 1.2 times eye length; distance between antennal sockets 2.5 times of the scape length (about 0.4 mm); approximate length ratio of 3rd–5th segments of maxillary palps 1.3: 1.0: 1.8. Pronotum transverse; widely rounded along anterolateral margins, caudal margin very weakly angulate (Figs. 4A, B, 5 B). Scutellum very small. Tegmina and wings shortened (Fig. 4A), only reaching 7th abdominal tergite; rounded apically; venation distinct; all main veins present; Sc thickened (well visible on ventral side of tegmen). Wings completely hidden under tegmina, much shorter than tegmina, with a simplified venation. Anterior margin of fore femur armed as in the type B, with 6 spines, including 2 apical ones. Fore tibiae not thickened distally. Structure of hind tarsi as described for the genus (see above); arolium vestigial. Abdominal tergites 5th and 6th specialized (Fig. 5 C). 5th tergite with median membranous area and thin transverse sclerotized strip located in the centre of this area (Fig. 5, s.str.). 6th tergite with larger membranous area, as compared with 5th tergite, membranous area separated by transverse sclerotized strip into two parts (Fig. 5, s.str.), anterior part with membranous tubercle and small transverse sclerotized plate at base of tubercle. Posterolateral angles of tergites obtuse (Fig. 5 C). Anal plate (tergite X) with the widely rounded caudal margin and a distinct median incision (Fig. 5 D, E). Cerci short, flatten, with segments distinctly separated (Fig. 5 D, E). Paraprocts of the blaberid-type, right paraproct with a sclerotized outgrowth directed cranially (Fig. 5 E). Hypandrium weakly asymmetrical, with caudal margin rounded and projected caudally (Fig. 5 F); a median tooth present (Fig. F, G, m.t.); right stylus fusiform, bent at its base (Fig. 5 F), left stylus absent.
Male genitalia (Fig. 5 H–N). Right phallomere (R+N) with caudal part of sclerite R1T transverse (Fig. 5 H, I, c.p.R1T), cranial part of R1T and R2 rounded (Fig. 5 H, I, cr.p.R1T); R3 with branches of unequal length and width; R5 wide, weakly sclerotized; bristles absent. Sclerite L2D (L1) divided into basal and apical parts (Fig. 5 J); basal part rod-like, moderately widened cranially (Fig. 5 J, b.L2D); caudally with "curved upward subsclerite" (Fig. 5 J, K, u.s.); apical part in shape of sclerotized and folded plate (Fig. 5 J, K); bristles absent. Sclerite L3 (L2d) with distinct basal subsclerite (Fig. 5 L–N, b.L3); "folded structure" distinct, with bristles (Fig. 5 L–N, f.s.); groove hge present. Sclerite L4U (L3d) distinct.
Female unknown.
Measurements (mm). Head length: 1.9, width 1.9, pronotum length 2.5, width 3.7, tegmina length 4.8, width 2.3.
Comparison. The new species readily differs from all its congeners in having the distinctly shortened tegmina and wings. R alexeevi, sp.nov. is similar to R. euptera, sp.nov. in the presence of abdominal tergal glands, but can be readily distinguished from it by the location and structure of these glands (on the 5th and 6th tergites in R. alexeevi, sp.nov., contrary to the 6th and 7th ones in R. euptera, sp.nov.), and the presence of the apical part of sclerite L2D in the male genitalia.
Note. The shortening of tegmina, the reduction of ocelli and arolia are probably evidence of a shift to a more reclusive lifestyle. The well visible epicranial sutures and the reduced ocelli are rather larval characters, i.e. the modus of evolution R. alexeevi, sp.nov. seems to be the retardational paedomorphosis (retrogenesis) (sensu Iordansky 2005).
description: Published as part of Anisyutkin, Leonid N. & Yushkova, Olga V., 2017, New data on cockroaches of the subfamily Epilamprinae (Dictyoptera: Blaberidae) from India and Sri Lanka, with descriptions of new species and the genital complex of Aptera fusca (Thunberg, 1784), pp. 41-64 in Zootaxa 4236 (1) on pages 49-52, DOI: 10.11646/zootaxa.4236.1.2, http://zenodo.org/record/322014