Metopomystrum ankeri Cadena-Castañeda & Tavares, 2025

Cadena-Castañeda, Oscar J., Quintana-Arias, Ronald Fernando, Infante, Ivette Coque, Silva, Daniela Santos Martins & Tavares, Gustavo Costa, 2025, Studies on pygmy grasshoppers: On the current Metrodorinae sensu lato classification (Orthoptera: Tetrigidae) with emphasis on American and Malagasy taxa, Zootaxa 5597 (1), pp. 1-265 : 119-124

Metopomystrum ankeri Cadena-Castañeda & Tavares , sp. nov.

( Figs. 79–82 , Maps 1 and 2)

Type material. Holotype. Male. COLOMBIA, Caldas Department, Florencia , montane rainforest, 9.VIII.2019, A. Anker & F.A. García Oviedo leg. ( CAUD) . Paratypes. 1 Female. COLOMBIA, Antioquia, Alejandría. J. Cardona-Granda leg. 1 Female. COLOMBIA, Antioquia, San Luis, in forest. G. Morales leg. ( CAUD) . 1 Female. COLOMBIA, Antioquia, Cocorná , Vda. El Choco. FCA. ACA, 6°01'48.5"N 75°09'55.8"W. 1300 m. 10-Jul-2012. C. Niño. ( UNAB) .

Description. Male. Medium-size (11 mm) and slender ( Fig. 79 ). Coloration. Dark brown with spots and stripes in light brown, ocher, and white ( Fig. 79A ). Frontal view of the head brown, with whitish and ocher sections ( Fig. 80A ), and white spots also present throughout the body ( Figs. 79B , 80B ); dorsally, head light brown; eyes chocolate brown ( Fig. 80C ); from the eyes, a post-ocular stripe extends laterally; antennae with the scape and pedicel ocher, segments 3 to 8 dark brownish with ocher-lined distal edges, segments 11 and 14 ocher at the basal half and dark at the distal half, while segments 12 and 13 the opposite ( Fig. 80B ); clypeus light brown in the upper half with two dark brown spots at the center of the upper margin, and the lower half grayish; labrum dark brown with two large white spots on the upper half and, within each spot, a smaller brown spot adjoining the upper margin; palpi white with diffuse brown spots ( Fig. 80A ). Pronotal disc brown with alternating diffuse black stripes; lateral lobes dark brownish black in the upper half and white in the lower half ( Figs. 79B , 80C ). Foreleg ocher with dark stripes ( Fig. 80D ); mid femur brown, mid tibia with alternating rings of ocher and brown ( Fig. 80E ); hind femur dark brown in the lower half and grayish brown in the upper half, with a white stripe descending perpendicularly from the upper margin at the midpoint of the femur length to the boundary between the lower and upper halves, then projecting parallelly to the genicular region ( Fig. 79A ); hind tibia dark brown, with a small whitish stripe near the base, tarsomeres alternating between brown and white or ocher sections ( Fig. 79B ). Tegmina and hindwings black with venation softly outlined in white ( Fig. 80F ). Abdomen black covered with abundant tiny white spots. Head taller than wide, eyes occupying a third of the cephalic capsule; space between the eyes 0.8 times the width of an eye; scutellum narrow, not widened ( Fig. 80A ); fascial carinae parallel, poorly protruding in lateral view and nearly straight ( Fig. 80B ); lateral ocelli located near the fork of the frontal costa ( Fig. 80A ). Antennal grooves situated at the level of the lower margins of the eyes; antennae with 14 segments. Fastigium of the vertex projecting forwards and forming a conical “horn” longer than the maximum length of an eye in lateral view ( Fig. 80B ), dorsum of the “horn” ovoid and with a shallow depression, apex rounded ( Fig. 80C ). Thorax. Anterior margin of the pronotum almost straight; prozonal carinae developed ( Fig. 80C ), pronotal apex thin and truncate in dorsal view ( Fig. 79B ). Median carina present but poorly subelevated; internal lateral carinae straight in lateral view; external lateral carinae finely denticulated and convergent ( Fig. 79B ); infrascapular area thin and short, extending to level of first abdominal tergite ( Fig. 79A ); lower margin of lateral lobes ovoid-shaped, and rounded; posterior margin of lateral lobe almost straight ( Fig. 80C ). Wings. Tegmina lanceolate, with the anal margin tapering straight towards the apex, costal margin rounded and, as they converge, apex narrow and rounded ( Fig. 80F ); hindwings exceeding the length of the abdomen and reaching the apex of the pronotum ( Fig. 79 ). Legs. Fore and mid femora rectangular-shaped, dorsal and ventral margin little undulated, almost straight ( Figs. 80D, E ); fore and mid tibiae slender and armed with small spines on distal half of the ventral margin; hind femur slender with the antegenicular and genicular teeth developed ( Fig. 79A ); hind tibia armed dorsally with five inner and six outer small spines on each dorsal margin ( Fig. 79B ). Abdomen unmodified. Tenth tergite divided dorsally, which connects to the epiproct; cerci conical, tapering towards the apex and moderately diverging towards the sides ( Fig. 80G ); epiproct triangular and longer than wide. Penultimate sternite quadrangular, as long as the subgenital plate and little upcurved ( Fig. 80G ); subgenital plate short, triangular, and apex with a U-shaped mid-notch ( Fig. 80H ).

Female. Similar to the male, differing in ambisexual characters and with some coloration variations ( Fig. 81 ): epiproct lanceolate with a rounded apex; valves of the ovipositor moderately thickened, covered with bristles; subgenital plate quadrangular, almost as wide as long, with a small medial extension on the posterior edge.

Measurements (in mm) male / females. CFP: 11 / 12–17. PL: 8.9 / 11–15. PLB: 2.5 / 3.0–3.5. FF: 1.6 / 2.0–2.5. FL: 1.7 / 1.8–2.4. MFL: 1.9 / 2.1–2.6. MTL: 1.7 / 2.0–2.5. HL: 4.7 / 5.5–5.9. HW: 1.4 / 1.5–2.0. HTL: 4.0 / 5.0–5.4.

Comparison. The new species differs from M. amazoniense , M. apterum , and M. muriciense because these species do not have well-developed wings, and the pronotum does not surpass the apex of the hind femur. Among the species with wings and a prolonged pronotum, M. ankeri sp. nov. is similar to M. pehlkei ; both species have the tegmina and dorsal margin of the pronotum unicolor, distinguishing them from M. lilianae . M. ankeri sp. nov. and M. pehlkei differ in the shape of the tegmina, which is lanceolate in the new species vs. ovoid, and the pronotum of M. pehlkei is more elongated than in the new species. Additionally, M. ankeri sp. nov. has a whitish stripe on the upper half of the hind femur ( Fig. 82 ), which is absent in M. pehlkei .

Remarks. Two paratype females show variation in their measurements and coloration. The female from Alexandria ( Figs. 81A, B ) has a coloration pattern more similar to the holotype male, and the pronotum’s apex moderately surpasses the hind femur’s apex. In contrast, the female from San Luis ( Figs. 81C, D ) is larger, and her coloration tends to be reddish-brown, with the pronotum’s apex widely surpassing the hind femur’s apex. Both females have the characteristic whitish stripe of the hind femur.

Etymology. We dedicate this species to the biologist, wildlife photographer, and dear friend Dr. Arthur Anker, who collected this species.

Figures

FIGURE 79. Metopomystrum ankeri Cadena-Castañeda & Tavares sp. nov. Male holotype habitus. A. Lateral view and, B. Dorsal view.

FIGURE 80. Metopomystrum ankeri Cadena-Castañeda & Tavares sp. nov. Male holotype. A. Frons. B–C. Head and thorax in lateral and dorsal views respectively. D. Fore femur. E. Mid femur. F. Tegmina. G–H. Terminalia in lateral and ventral views respectively.

FIGURE 81. Metopomystrum ankeri Cadena-Castañeda & Tavares sp. nov. Female paratypes. A–B. Habitus lateral and dorsal of female from Alejandría (Antioquia, Colombia). C–D. Habitus lateral and dorsal of female from San Luis (Antioquia, Colombia).

FIGURE 82. Metopomystrum ankeri Cadena-Castañeda & Tavares sp. nov. Male holotype in live condition. Florencia, Caldas Department, Colombia, (type locality). Photo: Arthur Anker.