Mazaea Stål, 1876

Genus Mazaea Stål, 1876 View in CoL

( Figs 1; 3B, C, E, F; 6; 7 B-H; 8A, B; 9; 18A, B; Tables 1; 2)

Mazaea Stål, 1876: 54 View in CoL .

Eubocoana Sjöstedt, 1931: 21-22 View in CoL , Plate 2, figs 7, 7a, 7b; n. syn.

TYPE SPECIES. — Mazaea granulosa Stål, 1876 , by monotypy.

DESCRIPTION

Morphology as for family, but typically slightly larger than Ixalidium and Rowellacris Ritchie & Hemp n. gen., differing principally by characters given in key. Medium size (male c. 20-28 mm; female c. 27.5-39 mm).

Head

Antennae 22-segmented, slightly longer than, as long as, or slightly shorter than head and pronotum together. Integument strongly granulose, rugose and punctate. Head with fastigium and frons above median ocellus strongly projecting in front of eyes. Fastigium of vertex forming an ogival arch, longer than, as long as, or slightly shorter than its maximal basal width, with bluntly pointed apex, lateral carinae and variably expressed median carinula ( Fig. 3E, F). Head width across eyes from slightly less to slightly more than three times vertex length. Eyes protuberant and globular when seen from above ( Fig. 3E), ovoid in lateral view. Frons produced, blade-like above and between antennal bases, meeting lateral carinae of fastigium dorsally at about 120°; frontal ridge below antennae sulcate, becoming broader with irregular lateral carinae, constricted below median ocellus, widening and obsolescent ventrally; facial carinae irregular, diverging ventrally with acute lower angles.

Thorax

Pronotum tectiform ( M. granulosa ) to subcylindrical ( M. tristis n. comb.), not or only partly covering mesonotum, strongly granulose, with distinct lateral carinae ( M. granulosa ) or coarsely rugose and granulose, with small tubercles and without distinct lateral carinae ( M. tristis n. comb.), with one deep transverse sulcus dividing prozona, and another separating it from metazona; prozona more than three times length of metazona, with raised irregular dorso-medial triangular tuberculate area, widest at anterior margin, narrowing towards first transverse sulcus; second triangular dorso-medial tubercular area extending from anterior sulcus to hind margin of pronotum and traversed by posterior sulcus; posterior margin of pronotum scalloped, medially indented, ornamented with small tubercles. Mesonotum dorsally short, carinate, rugose and puncate in anterior half (when visible), granulate in posterior half; hind margin with small papillate tubercles and with medial raised tuberculate mass. Metanotum and abdominal tergite 1 somewhat humped, with hour-glass-shaped medial raised tuberculate areas, widest at anterior and posterior margins.

Prosternal tubercle acutely subconical, with dentate apex, subvertical anteriorly, but obliquely sloping and concave posteriorly. Mesosternal interspace open, trapezoidal, longer than its minimum width; mesosternal lobes smoothly curving. Metasternal interspace open, longer than its minimum width, metasternal lobes bluntly rectangular. Elytra and wings absent.

Abdomen

Abdominal tergites carinate; tergite 1 with distinctly angled shoulders marked by irregular line of granulate tubercles and with hour-glass-shaped raised medial tuberculate area, as for metanotum; tympanum large, suboval, sclerotised; tergite 2 and subsequent tergites progressively less raised and tuberculate in medial area. Supra-anal plate ( Fig. 9F) divided into basal and apical portions by a transverse furrow, with basal part narrowly embedded into last abdominal tergite, with broad medial longitudinal groove; its hind margin slightly carinate, shallowly concave medially and with small, rounded flanges at its outer ends ( Figs 7B; 9G). Hinged apical part shield-shaped with subacute apex. Subgenital plate conical, postero-ventrally slightly concave in lateral view, with papillate apex, with shallow dorso-medial furrow widening forwards and with its anterior medial margin forming a domed membranous cowl over apex of aedeagus. Cerci elongate conical, with digitate tips, clothed with long setae.

Legs

Hind femur moderately robust, male c. 3.4-4 times as long as maximum depth, female; 3.5-5.1 times ( Tables 1; 2), with serrated upper carina, granulose upper and lower marginal areas, rounded knee lobes. Hind tibia with 8-9 inner and 7 outer spines, small external apical spine usually present ( Fig. 3C), but sometimes obsolete. Arolium large, diameter less than claw length.

Male genitalia ( Figs 7; 9)

Somewhat similar to those of Ixalidium , but much more robust, enclosed within a narrow membranous pouch. Epiphallus with bridge from above semi-circular ( Figs 7D; 9E), with nascent ancorae ( Figs 7C; 9F) and with pointed lophi, directed medially and dorsally. Ectophallus with ventral lobe small and distinct from rami, closely applied to base of aedeagus ( Figs 7E, F; 9B, D). Ventral lobe apodeme (ventral infold of Dirsh, 1956) present as a narrow thin bi-layered sheet below endophallus, broadening and bifurcating capitad ( Fig. 7F), not illustrated by Dirsh (1966, fig. 41). Dorsal (basal) fold of cingulum forming a trilobate membranous cushion appressed to anterior wall of aedeagus, with its medial lobe produced caudad into a stalked vesicle, normally overlapping lowered antero-dorsal rim of aedeagus, so as to lie within and partially plug lumen of aedeagus (shown dislodged in Fig. 18A); lateral wings of dorsal fold produced posteriorly, curving around each side of aedeagus. Zygoma and rami of cingulum reduced, collar-like. Separate caudally-directed rounded sclerotised dorso-lateral lobes (supra-rami of Eades 1962) with denticulate outer surfaces on postero-dorsal margins of rami. Apodemes of cingulum strongly elongated, slightly diverging towards apices; supra-rami with spur-like supplementary apodemes directed anteriorly, as in Ixalidium . Arch of cingulum formed by paired bilateral sclerites arising from sides of endophallus, with additional pair of slender apodemes of cingulum projecting anteriorly ( Figs 7F; 9C) and with a bifurcated stout dentate process (incipient valves of cingulum?) projecting caudad ( Fig. 18B, C), appressed to dorso-lateral surface of aedeagus, normally concealed by dorsal fold of ectophallic membrane. Endophallus similar to that of Ixalidium , in three sections ( Fig. 7 F-H); apodemes and medial sclerites separated from posterior section (apical sclerites) by articulated break; endophallic apodemes strongly-developed, proximally well-separated, upwardly curving, slightly excurved (smaller in Ixalidium ), rising to their posterior point of fusion, then sharply recurved downwards and caudad. Flanges of endophallus visible as short, pointed, medially-directed projections on internal surfaces of endophallic apodemes ( Figs 7G; 9A) anterior to their junction, adjoining confluence of ejaculatory duct and ventrally placed ejaculatory sac ( Fig. 7 F-G). Spermatophore sac forming flattened strip on dorsal surface of conjoined medial sclerites; ventral surface of medial sclerites of endophallus with alternating transverse striations of sclerotised (dark) and unsclerotised (light) cuticle ( Fig. 7F, H). Posterior (apical) section of endophallus (aedeagal sclerites) fused, elongated and upcurved, separated from medial sclerites by hinged break and forming well-developed aedeagus with genital pore at its apex, dorso-ventrally compressed ( Fig. 7G, H); anterior margin of aedeagal apex excavated to receive vesicle of medial lobe of dorsal fold of cingulum. Subgenital plate about as wide as long (when flattened); dorsal surface with medial pouch present, overlying common oviduct; egg guide narrow, continuous with inner margins of floor pouches; post-vaginal sclerites transverse, elongate reniform, with small, pigmented areas of columellae at their inner ends ( Fig. 6C).

Female genitalia ( Fig. 8)

Spermathecal duct extremely long (several times length of body) ( Fig. 8A), repeatedly coiling and looping, forming two distinct clusters to left and right sides, occupying much of abdominal cavity between gut and ovaries as far forward as tergite 2, ending with short vermiform subapical diverticulum and vermiform apical diverticulum nearly ten times as long ( Fig. 8B).

Measurements

Tables 1; 2.

Coloration ( Figs 3B, E; 19C, D)

Male: General ground colour variable, especially in M. granulosa , light to dark brown with lighter banding and spotting and some darker brown to black areas. Antennae in basal half pale buff dorso-externally with darker speckling, pale buff or pale yellow ventro-internally (sometimes light red in M. granulosa ), darkening to black towards tips on dorsal and ventral surfaces. Head light to dark brown, sometimes with darker speckling. Eyes light to dark brown with or without pale horizontal line across upper third, continuing caudad across occiput; second oblique curved pale line sometimes crossing lower third of eye, rising sharply caudad.

Dorsum of pronotum showing a range of pattern morphs in M. granulosa , some with dark brown medial longitudinal hour-glass marking framing median carina, alternately constricted and widened in prozona and metazona, bounded laterally by paler longitudinal areas of varying width, externally following inner edges of lateral carinae; others unicolorous lighter or darker brown dorsally, with or without pale buff to light brown longitudinal bands along inner margins of pronotal lateral carinae, continued obliquely downwards on meso- and metathoracic pleurae to episternum above hind coxae; dorsum in M. tristis n. comb. dull speckled mid brown, without pale lateral lines, with tubercles blackish except for pale buff tubercles on hind margin. Lateral lobes from light to dark brown, sometimes lacking clear markings, sometimes with pale oblique blotches in prozona, rising from antero-ventral angle caudad, interrupted by first transverse sulcus. Prosternum pale buff, sometimes with dark grey-brown spotting; meso- and metasternum anterior and lateral margins pale, becoming darker brown or grey-brown medially. Dorsum of meso-and metathoracic tergites mid brown medially (with greenish tinge towards lateral plates in M. tristis n. comb.); triangular epimeron on metathoracic pleura anterior to tympanum with large dark brown or black spot in caudal half.

Dorsum of abdominal tergite 1 often with pale tubercles at posterior margin; tergites 1-4 mid brown with paired dorso-lateral dark transverse dashes on hind margins; tergites 5 and 6 dorso-laterally paler; lateral lobes of tergite 2 with pale upper lateral area and dark shiny patch below; tergites 3-5 laterally with dark brown to blackish shiny areas, normally concealed by widest part of hind femur; tergites 7-10 darker (with olive greenish tinge dorso-laterally in M. tristis n. comb.). Abdominal sternites with lateral margins light brown with darker speckling, with dark brown or grey-brown patches medially, becoming chevrons pointing capitad on sternites 7-8. Cerci dorsally light to mid brown with subapical transverse black band, ventrally black with pale tips. Supra-anal plate mid brown, speckled with darker brown. Paraprocts blackish. Sternite 9 to tip of subgenital plate with continuous or interrupted irregular medial longitudinal dark grey-brown to black band, sometimes obsolescent.

Fore and mid legs mid dark grey-brown with lighter and darker speckling. All coxal joints blackish below. Hind femur externally and in upper internal area light to mid brown, with three indistinct oblique darker bands, interrupted in medial area, situated at base, 2/5 from base, and between 3/5 from base and knee; knee lunules dark brown. Hind femur internally with medial area dark brown to black throughout, apart from pale buff area in upper half at base, narrow irregular or incomplete pale transverse band half way from base sometimes reduced to small pale blotch on ventral internal carina and small pale mark just above knee; ventral internal area buff or greyish. Hind tibia dorsal and ventral surfaces buff to grey buff, with smoky blotches dorsally in basal half, becoming more evenly smoky grey brown towards tarsi; external spines and claws smoky buff with black tips, sometimes black at base or all black; internal spines usually darker with black tips or all black.

Female

Coloration similar to male but less contrasted. Triangular epimeron on metathoracic pleura anterior to tympanum without dark blotch; abdominal tergites 2-4 only with lateral dark brown to black shiny areas.

HISTORY

The genus Mazaea was described by Stål (1876) for his single female specimen of an apterous species that he named M. granulosa on account of the small granular tubercles covering the integument of the thorax and hind legs. Stål evidently did not know the provenance of his type specimen which must have been acquired in West Africa by a visiting European before 1876. Given the known geographical range of the genus and the fact that there were few European settlements on the coast of the Bight of Biafra at that time, it is likely that the type specimen came from a forested location close to what is now Douala in the littoral region of SW Cameroon. However a provenance from coastal areas of Congo, DR Congo, Gabon or Equatorial Guinea is also possible.

Bolívar (1908:105) described M. granulosa var. cingulata from “Loagna” [sic] (probably Loanga, Congo Republic), but this was synonymised by Kirby (1910) apparently as a cataloguing convenience, since he did not recognise varieties. Dirsh (1966:102) repeated the synonymy. All other published records of Mazaea have been attributed to M. granulosa . Sjöstedt (1931) assigned Mazaea , Barombia and his own Eubocoana to “ Acanthini”, an informal grouping possessing an external apical tibial spine, but he considered Ixalidium to belong to the “ Anacanthini”, which lacked this spine. Dirsh (1965) also used the presence or absence of this spine to organise his key to the genera of the Catantopinae .Today this character would be perceived as potentially subject to rapid evolution. Hollis (1975: 197) studied the presence or absence of the external apical tibial spine within and between different genera of Oxyinae Brunner von Wattenwyl, 1893 . In Thanmoia Ramme, 1931 he noted that it could be present or absent and even show both conditions on the two hind legs of a single individual.

REMARKS

Genomic evidence presented elsewhere in this paper ( Fig. 1) now suggests that the West African Mazaea is the most basallypositioned subclade of the Ixalidiidae Hemp, Song & Ritchie n. fam., which agrees well with the ancestral character states that it exhibits (e.g. the large ejaculatory and spermatophore sacs, elongated apodemes of cingulum and recurved endophallus), that are shared with the East African Ixalidium . These characters have been lost or greatly modified in the other East African subclades of the family, Tangana and Rowellacris Ritchie & Hemp n. gen. Mazaea is also shown to be a member of the Ixalidiidae Hemp, Song & Ritchie n. fam. on the basis of its general habitus ( Fig. 3) and especially its genitalia ( Fig. 6). The external morphological features which distinguish Mazaea from the genus Ixalidium are its strongly granulose integument, more pointed vertex, pointed prosternal tubercle (spathulate in Ixalidium ) and the presence (usually) of a small external apical spine on the hind tibia (absent in Ixalidium and other East African members of the family).

INCLUDED SPECIES

Mazaea granulosa Stål, 1876 View in CoL

Mazaea tristis ( Sjöstedt, 1931) n. comb.