Poreuomena biaculeata, Hemp & Massa, 2021

Hemp, Claudia & Massa, Bruno, 2021, Biogeographical and evolutionary aspects of a Guineo-Congolian bushcricket tribe: Revision of the genera Cestromoecha Karsch, 1893 and Poreuomena Brunner von Wattenwyl, 1878, with the description of new species (Orthoptera, Tettigoniidae, Phaneropterinae), Deutsche Entomologische Zeitschrift 68 (1), pp. 45-79 : 45

Poreuomena biaculeata sp. nov. Figs 29-35

Material examined.

Democratic Republic of the Congo. Léopoldville (today Brazzaville) 1937, A. Tinant (holotype ♂) ( MRAC) .

Diagnosis.

Very closely related to P. wilverthi , a species widespread in the Congo basin and the Albertine Rift. P. biaculeata sp. nov. has the 10th abdominal tergite deeply split into two lobes (Figs 33 , 34 ), while in P. wilverthi the 10th abdominal tergite is not divided as deeply, just at the apex however, with a median groove. The cerci in P. wilverthi are thick but smoothly tapering to the apex with an acute tip (Figs 105 , 106 ), while in P. biaculeata sp. nov., the cerci are thick at the base and then suddenly narrowing midway forming a finger-like but pointed and sclerotized apical section (Figs 32-34 ). P. biaculeata sp. nov. is also closely related to P. crassipes with a similar tegminal flap of the 10th abdominal tergite but differently shaped cerci.

Description.

Male. Typical Poreuomena species with wings protruding over the body by only a few mm (Fig. 29 ). Where tegmina meet, when folded, interior part of cells of dark colour while surrounding and elevated veins green (tawny in preserved insect). Rs branching off in the first half of the basal part of the tegmen. Tegmina with two flaps at their base, the flap of the left wing smaller and more pointed than the broader flap with a rounded tip on the right tegmen. The stridulatory rib marked dark brown on the flap of the left tegmen, uniformly brown on the right tegmen. Beneath flaps, tegmina with narrow longish, oval brown markings. Stridulatory file on the underside of left flap about 1.1 mm long; teeth at the apical part of the left flap very densely set and gradually getting larger to the middle of the file where the teeth are largest and widely set. At the end of the file at the interior part, strongly curved with small and a few widely set teeth; with about 20 widely and in the middle large teeth, apically more than 30 very densely set teeth (Fig. 31 ). Stridulatory file on the right tegminal flap not as strongly developed but of similar shape and the same arrangement of the teeth. The 10th abdominal tergite of typical bilobate form, deeply divided medially thus forming two processes with upcurved posterior parts (Figs 33 , 34 ). Cerci thick at the base, then strongly narrowing and forming a sclerotised pointed apical tip (Figs 33 , 34 ). Subgenital plate with two slender but short lobes (Fig. 35 ). Titillators present (two slender long structures), protruding between the subgenital plate and the cerci (Fig. 32 ).

Female. Unknown.

Measurements

(mm). Male (n = 1). Body length: 22; pronotum length: 3.7; length hind femora: 21.2; length of tegmina: 28.3; width of tegmina: 4.3.

Distribution.

Congo Basin.

Etymology.

Named after the shape of cerci that are similar to two stings, from Latin biaculeatus (= with two stings).

Figures

Figures 29 - 35. Morphological details of male Poreuomena biaculeata sp. nov. Habitus (29), left tegminal flap with stridulatory file on the underside (30), stridulatory file on the underside of the left tegminal flap (31), abdominal apex in lateral (32) and rear view (33), cerci (34), subgenital plate (35).

Figures 101 - 107. Morphological details of male Poreuomena wilverthi. Habitus (101, syntype, 102), stridulatory file on the underside of the left tegmen (103), lateral view on apex (104), subgenital plate (105), apex ventral-lateral (106) and dorsal-lateral view (107).