Pterotiltus bioko Oumarou-Ngoute & Rowell, 2025

Oumarou-Ngoute, Charly, Song, Hojun, Mariño-Pérez, Ricardo, Woo, Brandon M., Linde, Jackson & Rowell, C. H. F., 2025, A new species of Pterotiltus Karsch (Orthoptera, Acrididae, Oxyinae) from Equatorial Guinea, Journal of Orthoptera Research 34 (2), pp. 201-212 : 201-212

publication ID	https://doi.org/10.3897/jor.34.141073
publication LSID	lsid:zoobank.org:pub:F0F9144F-E059-4905-A359-09FB8094CA67
DOI	https://doi.org/10.5281/zenodo.15723258
persistent identifier	https://treatment.plazi.org/id/AE02D48A-1018-5769-A499-634BD6F095C3
treatment provided by	Journal of Orthoptera Research by Pensoft
scientific name	Pterotiltus bioko Oumarou-Ngoute & Rowell
status	sp. nov.

Treatment

Pterotiltus bioko Oumarou-Ngoute & Rowell sp. nov.

Figs 1 View Fig. 1 , 2 View Fig. 2 , 3 View Fig. 3 , 4 View Fig. 4 , 5 View Fig. 5 , 6 View Fig. 6 , Tables 1 View Table 1 , 2 View Table 2

Material examined. —

Holotype: EQUATORIAL GUINEA, Bioko Island • ♂; Road to Ureka , Reserva Cientifica de la Caldera de Luba, Bioko Island; 03°13'3"N, 008°21'4"E; altitude 1345 m; 15-xii-2023; H. Song, R. Mariño-Pérez, J. B. Linde, B. M. Woo, & C. Oumarou-Ngoute leg.; specimen N °. 8012023 D ; MfN GoogleMaps . Paratype: EQUATORIAL GUINEA, Bioko Island • 1 ♀; Pico Basile National Park , Bioko Island; 03°23'20"N, 008°29'51"E; altitude 1374 m; 18 December 2023; H. Song, R. Mariño-Pérez, J. B. Linde, B. M. Woo, & C. Oumarou-Ngoute leg.; specimen N °. 7732023 D ; MfN GoogleMaps .

Other material examined. —

EQUATORIAL GUINEA, Bioko Island; H. Song, R. Mariño-Pérez, J. B. Linde, B. M. Woo, & C. Oumarou-Ngoute leg. (36 ♂, 24 ♀) • 9 ♂; road to Ureka , Reserva Cientifica de la Caldera de Luba; 03°13'3"N, 008°21'4"E; altitude 1345 m; 15 December 2023; specimens N ° 7972023 D 7942023 D 7962023 D 7952023 D 7992023 D 7982023 D 8002023 D 8022023 D 8032023 D ; ONC GoogleMaps • 1 ♂; same information as previous; 03°12'57"N, 008°21'11"E; altitude 1370 m; specimen N ° 8122023 D ; ONC GoogleMaps • 2 ♂; same information as previous; 03°20'09"N, 008°35'07"E; altitude 1204 m; specimens N ° 7852023 D 7862023 D ; ONC GoogleMaps • 9 ♂, same information as previous; 03°12'7"N, 008°21'4"E; altitude 1192 m; specimens N ° 8452023 D 8312023 D 8332023 D 8342023 D 8372023 D 8322023 D 8362023 D 8352023 D 8462023 D ; ONC GoogleMaps • 3 ♀; same information as previous; 03°13'3"N, 008°21'4"E; altitude 1345 m; specimens N ° 7932023 D 7892023 D 7902023 D ; ONC GoogleMaps • 3 ♀; same information as previous; 03°20'09"N, 008°35'07"E; altitude 1204 m; specimens N ° 7792023 D 7812023 D 7832023 D ; ONC GoogleMaps • 10 ♀; same information as previous; 03°12'7"N, 008°21'4"E; altitude 1192 m; specimens N ° 8302023 D 8292023 D 8222023 D 8212023 D 8242023 D 8272023 D 8282023 D 8232023 D 8252023 D 8262023 D ; ONC GoogleMaps • 1 ♂; same information as previous;,, 03°13'3"N, 008°21'4"E; altitude 1345 m, specimen N ° 8382023 D ; RC GoogleMaps • 3 ♂: Pico Basile National Park , 03°38'53"N, 008°49'45"E; altitude 1374 m; 18 December 2023; specimens N ° 7702023 D 7712023 D 7722023 D ; ONC GoogleMaps • 7 ♂; Lago Biao , Reserva Cientifica de la Caldera de Luba; 03°21'20"N, 008°37'17"E; altitude 1831 m; 16 December 2023; specimens N ° 8082023 D 8092023 D 8112023 D 8072023 D 8052023 D 8062023 D 8042023 D ; ONC GoogleMaps • 2 ♂; same information as previous; 03°13'3"N, 008°21'4"E; altitude 1345 m; specimens N ° 7842023 D 7802023 D ; RC GoogleMaps • 3 ♀; Pico Basile National Park ; 03°38'53"N, 008°49'45"E; altitude 1374 m; 18 December 2023; specimens N ° 7742023 D 7752023 D 7762023 D ; ONC GoogleMaps • 5 ♀; same information as previous; 03°22'33"N, 008°28'48"E; altitude 1864 m; N ° 8392023 D 8402023 D 8432023 D 8422023 D 8442023 D ; ONC GoogleMaps • 1 ♂; same information as previous;; 03°38'53"N, 008°49'45"E; altitude 1374 m; 18 December 2023; specimen N ° 7692023 D ; ONC GoogleMaps • 1 ♂; Lago Biao , Reserva Cientifica de la Caldera de Luba; 03°21'20"N, 008°37'17"E; altitude 1831 m; 16 December 2023; specimen N ° 8102023 D ; RC GoogleMaps .

Type locality. —

Reserva Cientifica de la Caldera de Luba, Bioko Island, EQUATORIAL GUINEA.

Etymology. —

Toponymic, referring to Bioko Island, Equatorial Guinea.

Description. —

(Figs 1 View Fig. 1 – 6 View Fig. 6 , Tables 1 View Table 1 , 2 View Table 2 ). Male. Body of small size, average length of body 14.22 mm (Table 1 View Table 1 ); fastigium of vertex rounded or roughly pentagonal in dorsal view with a medial carina, its tip merging smoothly with frontal ridge. Frons slightly oblique; frontal ridge shallowly sulcate above medial ocelli, obliterated below; antennae longer than the combined length of head and pronotum together; eyes protuberant, inter-ocular space slightly wider than antennae scape. Pronotum dorsally crossed by three deep sulci; medial carina very weak or absent. Space between sulci 2 and 3 almost equal to or slightly wider than metazona in length; metazona short, accounting for less than 25 % of the pronotum length (Fig. 3 A View Fig. 3 ). Lateral margins of prozona tuberculate in dorsal view, anterior margin of prozona slightly convex, sometimes slightly notched in the midline. Posterior margin of metazona slightly convex and notched in the midline; prosternal process conical, vertical, pointed. Mesosternal space slightly longer than wide, lobes rounded; metasternal space open, about half of mesosternal space; micropterous. Tegmina minute, lobiform, shorter than, reaching, or barely exceeding middle of metathorax but not reaching mesothorax (Fig. 3 B View Fig. 3 ). Hind femur slender, 5 times longer than wide (Table 1 View Table 1 ); 6 to 7 external tibial spines, 8 to 9 internal tibial spines (Table 1 View Table 1 ), external apical spine present; paired internal tibial spurs longer than external spurs. Tympanum wide, oval or rounded. Last abdominal tergite divided, the hind margin with two small lobiform processes forming a minute furcula, the tips separated by 0.3–0.35 mm (Fig. 3 D, E View Fig. 3 ), cercus compressed laterally, slightly incurved, slightly shorter than or exceeding the tip of the subgenital plate, with acute apex. Supra-anal plate triangular in dorsal view with acute or slightly rounded apex; proximally in the plate there is a short medial longitudinal groove bounded posteriorly by a curved transverse ridge that extends across the width of the plate (Fig. 3 D View Fig. 3 ). Phallic complex (Figs 4 A, B View Fig. 4 , 5 A, B View Fig. 5 ) of large size for the genus, ectophallic membrane coarsely stippled and obscures most of the sclerites; epiphallus with large forwardly curved blade-like outer lophi; inner lophi absent (Figs 4 C, D View Fig. 4 , 5 C, D View Fig. 5 ). Anterior processes of epiphallus well developed, axially large and rounded, ancorae absent (Figs 4 C, D View Fig. 4 , 5 C, D View Fig. 5 ). Oval sclerites large with pronounced pointed tubercles on their ventral surfaces (Fig. 4 F View Fig. 4 ); valvular plate foliose, showing large lobes that dorsally join the cingulum by a well-prolonged arch. Cingular apodemes dorsally blade-like, incurved (Fig. 5 E View Fig. 5 ); cingular ramus laterally large, prolonged and rounded (Fig. 5 F View Fig. 5 ). Endophallic apodemes dorsally slender, laterally large, spatula shaped, with robust, long and pointed gonopore processes; endophallic process terminates on the ventral aedeagal sclerite which forms a part of the ventral aedeagal valve (Fig. 5 G View Fig. 5 ).

Female. In general, similar to the male. Female particularities: body of small to medium size, average L = 18.11 mm (Table 1 View Table 1 ). Lateral margins of prozona less tuberculate in dorsal view; last abdominal tergite short, divided, but the hind margin without a furcula. Cercus robust, very slightly compressed laterally almost conical, straight or very slightly excurved, equaling or slightly exceeding the supra-anal plate, with acute apex; supra-anal plate triangular in dorsal view, elongated, lingulate, with rounded apex. Ovipositor valves smooth, slender, long, with rounded apex; subgenital plate ventrally conical, distally with a medial groove bounded laterally by two inflated ridges, not projecting posteriorly beyond the posterior edge of the plate. Egg-guide slender, rod-like, long, about half of the ventral ovipositor valves in length (Fig. 3 C View Fig. 3 ). Dorsally, subgenital plate smoothly triangular, terminated by a straight and pointed egg guide at the tip; a pair of large sclerotized columellae that are prolonged by a pair of less sclerotized stripes (Fig. 6 A View Fig. 6 ). Bursa copulatrix large, dorsally with a longitudinal groove separating the bursa into two somewhat distinct lobes (Fig. 6 B, C View Fig. 6 ), spermathecal duct long; spermatheca with a hooked terminal ampulla and a developed lateral diverticulum (Fig. 6 B, D View Fig. 6 ).

Sexual dimorphism. —

(Table 1 View Table 1 ) The average length of pronotum (P) of males is 82 % of that of females. The male antennae are longer than those of females (after normalization, the ratio of male / female Ant = 1.23). In the males, the interocular space (IOS) is smaller than in the females (male / female IOS = 0.68, and 0.82 after normalization). Breadth of fastigium (Fast-B) is slightly shorter in males than in females (male / female Fast-B = 0.73, and 0.89 after normalization). There are generally less internal tibial spines in males than in females (male / female medians = 0.82) (Table 1 View Table 1 ). After normalization, the ratios of the various other body dimensions are closely similar in both sexes (Table 1 View Table 1 ).

Coloration. —

(Fig. 2 A – F View Fig. 2 ). Male. Body multicolored, predominantly black; scape and pedicel of antennae light green. First two or three segments of flagellum green, tip white or light green, the remaining segments brown. Fastigium of vertex green or green-black; vertex black, eyes black fading to brown when dried. Frons yellow-white; genae black in upper half and yellow-white or yellow in inferior half; clypeus, labrum, and palps green with whiter mottling. Pronotal disc black with a wide yellow patch at the anterior margin of prozona; metazona dorsally yellow; tegmina yellow; mesothoracic and metathoracic tergites black. Pronotal lobes black with two yellow patches, one in the antero-basal edge joining the yellow tripe of the genae, another at the postero-basal edge behind the third sulci of pronotum (in some specimens, the last yellow patch can join dorsally the yellow metazona to form a single stripe). Prosternum, mesosternum, and metasternum light-green; fore and middle femora orange-green, tibiae and tarsi orange-green fading green-brown or brown when dried. Hind femora orange-green; hind knee brown, upper lobes of hind knee brown, lower lobes brown-green. Hind tibiae and tarsi light green with black spines; tergite of first abdominal segment black, with paired yellow patches at the posterior margin; tergites 2 and 3 black; tergite 4 yellow-green or green or orange-green; all other abdominal segments green or orange-green.

Female. We observed two different female morphotypes: All are green but some (the majority) have red patches in pronotal lobes (Fig. 2 C View Fig. 2 ), the rest have yellow patches. The yellow-patched females looked newly molted (Fig. 2 D View Fig. 2 ), suggesting that the color difference is developmental and that mature females are all red. Body multicolored, predominantly green, fading brown when dried. Scape and pedicel of antennae green; flagellum brown with white or light brown tip. Fastigium of vertex and vertex green; eyes black fading to light yellow or brown when dried. Frons green, clypeus, labrum, and palps green. Genae green with a red or yellow stripe, narrow below eyes, widened toward the pronotal lobes, and continuous in two patches in the pronotal lobes. Pronotum disc green; tegmina yellow; mesothorax and metathorax green, prosternum, mesoternum, and metasternum yellow-green or light-green. Fore and middle femora proximally yellow-green or orange-green; distally light-green. Tibiae and tarsi light-green; hind femora externally green, internally yellow-green or orange-green. Hind knee brown; hind tibiae and tarsi green with black spines. All abdominal segments green.

Diagnosis. —

Of small size relative to the rest of the genus, with average L = 14.22 mm in male and L = 18.11 mm in female. Body predominantly black in male with wide yellow patches in pronotum, female genae green with a red or yellow stripe, narrow below eyes, widened toward the pronotal lobes, and continuous in two patches in the pronotal lobes, abdominal segments green (Table 2 View Table 2 ); different to P. apicalis (Fig. 7 View Fig. 7 ). Metazona short, accounting for less than 25 % of the pronotum length; tegmina minute, lobiform, shorter than, reaching, or barely exceeding the middle of the metathorax but not reaching the mesothorax. Furcula small, lobiform, the tips separated by 0.3–0.35 mm. Oval sclerites of epiphallus large, with pronounced pointed tubercles on their ventral surfaces; endophallic apodemes dorsally slender, laterally large, spatula shaped, with robust, long, and pointed gonopore processes; pronounced flexure (Table 2 View Table 2 ).

Distribution. —

(Fig. 1 View Fig. 1 ). Endemic to Bioko Island, Equatorial Guinea. Near Bacake Grande: 03°36'13"N, 008°53'20"E, 17-xii-2023, 165 m. Road to Riaba: 03°19'59"N, 008°42'30"E, 17-xii-2023, 724 m. Lago Biao, Reserva Cientifica de la Caldera de Luba: 03°21'20"N, 008°37'17"E, 16-xii-2023, 1831 m. Road to Ureka, Reserva Cientifica de la Caldera de Luba: 03°12'57"N, 008°21'11"E, 15-xii-2023, 1370 m; 03°12'7"N, 008°21'4"E, 15-xii-2023, 1192 m; 03°21'45"N, 008°35'06"E, 15-xii-2023, 1345 m; 03°20'09"N, 008°35'07"E, 15-xii-2023, 1204 m. Pico Basile National Park: 03°22'33"N, 008°28'48"E, 18-xii-2023, 1864 m; 03°24'22"N, 008°31'5"E, 18-xii-2023, 897 m; 03°38'53"N, 008°49'45"E, 18-xii-2023, 1374 m (Fig. 1 View Fig. 1 ).

Status of taxonomic materials. —

Good. Both sexes of the species are known; adequate numbers of specimens available in the field on Bioko Island; modern localities are known. Least Concern (LC) on the IUCN Red List.