Rhabdoblatta fotoi Nyame Mbia, Legendre & Biram, 2024

Mbia, Donald-L’or Nyame, Ngon, Eric Belmond Biram à, Legendre, Frédéric & Menbohan, Samuel Foto, 2024, Semi-aquatic Epilamprinae cockroaches (Blattodea: Blaberidae) in Cameroon: towards a revision of continental African species of Rhabdoblatta Kirby, 1903 and Africalolampra Roth, 1995, European Journal of Taxonomy 946 (1), pp. 1-57 : 25-29

Rhabdoblatta fotoi Nyame Mbia, Legendre & Biram à Ngon sp. nov.

urn:lsid:zoobank.org:act:5DDC7759-63FE-4690-B2F2-D77F9BCBE701

Figs 14–17

Differential diagnosis

Males can be readily distinguished from all other congeneric species by the presence and shape of the tergal gland on the 4 th tergite. Males of Rhabdoblatta lyncea also have a tergal gland on the 4 th tergite – although with a different shape – but no bulge on the 5 th one; instead, they show a small, transluscent, posteromedial knob on the 3 rd tergite (compare Fig. 13E with Fig. 30C ).

Etymology

Named after the Professor Foto Menbohan Samuel, who initiated this work.

Material examined

Holotype

CAMEROON • 1 ♂; Centre Region , Mefou watershed, Eloundem; elev. 569–675 m; Dec. 2019 – Nov. 2020; molecular sample BL943; MNHN-EP7600 .

Allotype

CAMEROON • ♀; same data as for holotype; MNHN-EP7601 .

Additional specimens

CAMEROON • 1 ♀, 2 ♂♂; same data as for holotype; MNHN-EP7590 to MNHN-EP7592 .

Description

Male HEAD. Triangular, about as long as wide, mostly brown ( Fig. 14C ). Eyes black, ocellar spots creamish with one dark spot below each of them. Labrum and clypeus brown, lighter than frons and vertex. Scape and pedicel light brown, while other antennal segments darker. Distance between eyes equals distance between antennal sockets.

PRONOTUM. Light brown, with scattered brown freckles except on its border ( Fig. 14D ). Pronotum roughly triangular but with middle of hind margin distinctly convex. Laterally deflexed.

TEGMINA AND WINGS. Fully developed, extending well beyond end of abdomen ( Fig. 14A–B ). Tegmina with rounded apex, light brown with veins darker, with numerous small dark brown maculae and few other larger. Sc thickened in ventral view. Hindwings light brown, darker anteriorly than posteriorly, with veins darker ( Fig. 14B ).

LEGS. Anteroventral margin of front femur of type B2, with 3 strong spines proximally ( Fig. 14C ). Tibial spines well-developped. Metatarsus of hind leg longer than other segments combined ( Fig. 14H ), inner margin with two rows of small spines ( Fig. 14I ). Arolium and tarsal pulvilli well-developed, the latter bordered by “additional spines” sensu Anisyutkin (2016). Claws symmetrical and finely serrated ( Fig. 14I ).

ABDOMEN. Coloration of abdominal sternites variable ( Fig. 14A, F ), dark brown medially but with dark spots of different sizes laterally. Fourth abdominal tergite specialized: tergal gland as in Fig. 14E , with two reddish rod-like processes directed anteriorly and meeting medially in an oval papilla with a deeply emarginated posterior margin. Fifth abdominal tergite also slightly specialized with a little bulge anteromedially ( Fig. 14E ). Supra-anal plate with its caudal margin with a slight medial incision and with fine, sparse setae ( Fig. 14G ). Subgenital plate uniformly caramel-colored, symmetrical, convex, with two curled and flattened styli ( Fig. 14F ). Cerci multisegmented, pubescent ventrally, with a black tip.

GENITALIA ( Fig. 15 ). Left phallomere R complex (L1 of MK64 and R70, and R2+R3+N of G96); cleft between R1T and R2, very thin, without protuberance; R3 membranous, indistinct (sensu Anisyutkin, 2016), in two parts. Sclerite L2d with its basal sclerite rod-shaped, very tapered, slightly enlarged at its base (L1 of G96); apical sclerite of L2d (L2vm of MK64, L2v of R70 and L1 of G96) crescent-like, its apical vertex more elongated than its basal vertex, and somehow bifid. Sclerite L3 (R2 of MK64, R70, and L2d of PG96) long but sclerotized only at its distal end, with a slender hook extremely bent and elongated, with a subapical incision (groove hge. sensu Klass 1997); inner margin of basal part of L3 not crenulated. No sclerite L4U.

Remarks

The male genitalia of Rhabdoblatta fotoi sp. nov. show some similarities with those of the genus Rhabdoblattella known from South-East Asia and India ( Anisyutkin 1999; Anisyutkin & Youshkova 2017). However, the new species lacks a median tooth along the hind margin of the subgenital plate, a diagnostic character of the genus Rhabdoblattella . Furthermore, the phylogenetic analysis using the 12S marker does not suggest a close relationship between Rhabdoblattella disparis Wang, Yang & Wang, 2017 and the new species ( Fig. 2 ). We therefore prefer to place the new species in the genus Rhabdoblatta .

Female

The female is very similar to the male, although a bit larger and without tergal specialization. Its subgenital plate is symmetrical, semi-circular, without styli but with very sparse setae postero-medially and on its hind margin ( Fig. 16 ).

Measurements of adults

Male (n = 1): pronotum length ×width: 4.5× 6.3, tegmina length: 20, overall length × width 15.3 ×7.

Female (n = 1): pronotum length ×width: 6× 6.8, tegmina length: 24.5, overall length ×width: 28.5 ×11.

Nymphs

Pictures of nymph are provided in Fig. 17 . In both male and female juveniles, tarsi of all legs with large yellowish bristles on the inner face; supra-anal plate serrated with a deep, rounded, medial incision. Male juveniles have two styli.

Molecular data

A portion of 12S rRNA has been obtained and is available under the GenBank accession number OR589771 (molecular extract BL943).

Habitat

Adults and nymphs of this species were found in all the rivers investigated.

Distribution

This species is only known from Cameroon.

Figures

Fig. 14. Rhabdoblatta fotoi Nyame, Legendre & Biram sp. nov., holotype, ♂ (MNHN-EP7600). A. Habitus in dorsal and ventral views. B. Frontwing and hindwing expanded. C. Head and frontlegs. D. Pronotum. E. Tergal gland on 4th abdominal tergite. F. Subgenital plate. G. Supra-anal plate, dorsal view. H. Hindleg, ventral view. I. Close-up on tarsi and serrated claws, ventral view. Scale bars: A–B = 5 mm; C, E–G, I = 1 mm; D, H = 2 mm.

Fig. 15. Rhabdoblatta fotoi Nyame, Legendre & Biram sp. nov., holotype, ♂ (MNHN-EP7600), genitalia. Abbreviations: see Material and methods. Scale bars = 0.5 mm.

Fig. 16. Rhabdoblatta fotoi Nyame, Legendre & Biram sp. nov., allotype, ♀ (MNHN-EP7601). A. Habitus in dorsal and ventral views. B. Subgenital plate, ventral view. Scale bars: A = 5 mm; B = 1 mm.

Fig. 17. Rhabdoblatta fotoi Nyame, Legendre & Biram sp. nov., male nymph (MNHN-EP7590). A. Habitus in dorsal and ventral views. B. Close-up on tarsi. Arrows point at some of the long yellowish bristles found on the tarsi. Scale bar = 5 mm.

Fig. 13. Africalolampra erubescens (Gerstaecker, 1883), allotype, ♀ (ZIMG-II-27340b). A. Habitus in dorsal and ventral views. B. Head. C. Labels. D. Subgenital plate. Photographed by Lara Lopardo (ZIMG). Scale bars: A = 5 mm; B–D = 1 mm.

Fig. 30. Rhabdoblatta lyncea (Gerstaecker, 1883), male specimen (LUHM). A. Habitus in dorsal and ventral views. B–C. Abdomen and close-up on tergal gland (C) in dorsal views. D. Abdomen in ventral view. E. Pronotum. F. Head and front femorae. G. ‘Cristallized’ slide of male genitalia. Scale bars: A = 5 mm; B, D–F = 1 mm. C, G not to scale.

Fig. 2. Maximum Likelihood tree obtained from the analysis of the 12S marker of various species of Epilamprinae Brunner von Wattenwyl, 1865 with IQ-TREE. Bootstrap supports are reported at each node, except when the values were below 50. African species are in bold. Newly sequenced specimens have their voucher numbers in parentheses (i.e., BL***).