Leptobasis guanacaste, Paulson, Dennis R., 2009

Paulson, Dennis R., 2009, A new species of Leptobasis from Costa Rica (Odonata: Coenagrionidae), Zootaxa 2239, pp. 62-68 : 63-66

Leptobasis guanacaste n. sp.

Type material. Holotype: 3 from Hacienda Taboga, Guanacaste Province, Costa Rica (10.33° N, 85.20° W), elevation 4 meters, 2 August 1967, leg. D. R. Paulson ( FSCA). Allotype: Ƥ same data but 14 July 1966 ( FSCA). Paratypes (28 3, 39 ƤƤ). Location as holotype and allotype, from following dates: 14 Jul 1966 (2 3, 5 ƤƤ), 16 Jul 1966 (8 3, 15 ƤƤ), 24 Jul 1966 (2 ƤƤ), 9 Aug 1966 (1 3, 2 ƤƤ), 24 Aug 1966 (1 Ƥ), 26 Aug 1966 (1 3), 25 Oct 1966 (2 3, 2 ƤƤ), 26 Oct 1966 (1 3), 17 Nov 1966 (1 Ƥ), 14 Jul 1967 (11 3, 10 ƤƤ), 2 Aug 1967 (1 3, 1 ƤƤ), 9 Aug 1967 (1 3) (3 and Ƥ paratype to each of FSCA, InBIO, KJT, NMNH, RWG, TWD, and UMMZ; remainder in DRP collection).

Description. Male holotype. Head. Glossy black above, including antennae; labrum very pale blue; postocular spots represented by narrow pale blue triangles extending forward along inner edge of each eye. Mouthparts cream-colored. Rear of head black in center, pale blue adjacent to eyes. Frons in profile rounded.

Thorax. Prothorax black above, pale orange on sides, orange spot in middle of anterior lobe. Posterior lobe rounded and projecting caudally. Mesostigmal plates small and mostly orange, more or less triangular and projecting upward from thorax (as in Fig. 8 ). Pterothorax orange, paler below and with black median stripe and narrow black humeral stripes with irregular median borders. Legs same shade of orange, tinged brown at distal ends of segments; spines black. Spurs on metafemur distinctive, one longer and appressed distally at 1/3 length, then row of 7 (left) or 6 (right) much smaller and slightly curved spines at 5/8–7/8 length (as in Fig. 7 ); metatibial spurs considerably shorter than intervening spaces; tarsal claws with vestigial supplementary tooth. Wings hyaline with brown veins; pt brown, a parallelogram with all sides subequal, covering slightly less than one cell (as in Fig. 11 ). Px 7 in right FW, 8 in other three wings. CuA extends 6 cells beyond quadrangle in all four wings.

Abdomen. S1-2 light orange, S3-7 black above and orange below, S7 with very narrow orange apical ring; S8-10 and appendages orange. Cerci in lateral view slightly more than one-third length of S10, quadrate, in posterior view a small black cornified spine on ventral surface projecting ventrally and laterally. Paraprocts two-thirds length of cerci, broad at base but narrowing abruptly to a short dorsolateral tubercle with pointed, cornified spine at end. Appendages of paratype in Figs. 1–4 . Genital ligula with two long basally directed slightly curved chitinized filaments on internal surface of terminal segment (as in Figs. 5–6 ) but with no internal fold.

Measurements. Total length 32 mm; abdomen length 27 mm; FW 15.8 mm; HW 15.0 mm.

Female allotype (not fully mature).

Head. Colored exactly as male, but duller, brown instead of black.

Thorax. Anterior lobe of prothorax pale orange, brown laterally; median lobe orange-brown dorsally, shading to pale orange laterally; posterior lobe darker brown, posterior margin very slightly concave rather than convex as in male. Pterothorax pale orange, with brown median stripe and only hint of brownish humeral stripe along mesopleural suture. Mesostigmal plates pale orange, rounded and projecting upward from thorax ( Fig. 9 ). Legs pale orange with slightly indicated darker bands. Spurs on metafemur not as modified as in male; proximalmost spine at midlength, moderately long, then followed immediately by 5 (left) or 4 (right) spines, distalmost slightly longest; metatibial spurs about same length as intervening spaces (notably different from male). Wings as male, but pt pale tan; 9 Px in both FW, 7 Px in both HW. CuA extends 5 cells beyond quadrangle in both FW, 6 cells beyond in both HW.

Abdomen. S1-2 orange with brown at posterior margin. S3-7 black above, orange below; proximal 1/6 of S3 orange; S8-10 orange, somewhat obscured with brown wash laterally. No vulvar spine on S8. Ovipositor valves curved, extending slightly beyond cerci on S10 ( Fig. 10 ). Outer valve of ovipositor with single row of about 23 tiny black teeth.

Measurements. Total length 30.5 mm; abdomen length 25 mm; FW 18.0 mm; HW 17.0 mm.

Variation in paratypes. Mature females have top of head and front of thorax glossy black, with blue labrum, postocular spots, and narrow antehumeral stripe. Abdomen entirely black above, pale orange-brown below, paler color extending higher on sides of S8-10. Metatibial spurs variable in length and distance apart in both sexes. See Coloration in Life below for more details.

Measurements. Ten paratype 3 total length 31.5–35.0 mm (mean 33.2 mm), abdomen length 26.7– 29.5 mm (mean 28.2 mm), FW length 15.8–17.0 mm (mean 16.3 mm), HW length 14.7–16.0 mm (mean 15.5 mm). Ten paratype ƤƤ total length 28.0– 32.5 mm (mean 30.2 mm), abdomen length 23.8–27.0 mm (mean 24.9 mm), FW length 17.3–19.0 mm (mean 17.9 mm), HW length 16.3–18.3 mm (mean 17.0 mm).

Coloration in life. ( Fig. 12 ). Mature male eyes black on upper third, greenish on lower two-thirds; postocular spots blue-green; prothoracic spot, legs, and face yellow. Thorax, S1-2, and S8-10 orange. Mature female quite unlike male except for similar eye color. Head black, face and postocular spots bluish; thorax black above, greenish on sides. Abdomen black with some dull orange markings ventrolaterally on S8-10. Substantial color changes with age, as in other Leptobasis species. Post-tenerals of both sexes mostly orange, with S4-7 quickly becoming blackish; looking much like L. vacillans at this stage. Apparently quickly develop to immature stage, in which female colored somewhat like mature male, but face and postocular spots orange; thorax orange with black median stripe, legs orange; abdomen black, with orange markings low on S8-9 and S10 entirely orange.

Diagnosis. Leptobasis guanacaste is easily distinguished from all other named species of its genus by its color pattern; no other coenagrionid in its range looks like the mature male. It is the only Leptobasis in which mature individuals lack the typical coenagrionid pattern of median and humeral thoracic stripes. The orange thorax with black median stripe and black abdomen with orange tip are found in males of no other Leptobasis . Some other Leptobasis have orange immatures, but they lack the black median thoracic stripe that develops during maturation in L. guanacaste . In addition, male L. guanacaste has a unique combination of short, angled, and spined cerci and even shorter paraprocts. It shares with L. candelaria distinctive metafemoral spines and genital ligula and a relatively short ovipositor. In addition, female L. guanacaste is unique in its genus in the slightly concave posterior border of the prothorax; this is concave in all other species.

Figures

FIGURE 11. Wings, male paratype of Leptobasis guanacaste.

FIGURE 12. Male (above) and female (below) of Leptobasis guanacaste, at Hacienda Taboga, Guanacaste Province, Costa Rica (photos by DRP).

FIGURES 1 – 10. Leptobasis guanacaste. 1 – 4. S 10, male paratype. (1) lateral view; (2) mediodorsal view; (3) medioventral view; (4) posterior view. 5 – 6. Genital ligula, male paratype. (5) lateral view; (6) entolateral view. 7. Metafemur, male paratype, view of flexor surface. 8 – 9. Posterior lobe of pronotum and mesostigmal plates, dorsal view. (8) male paratype; (9) female allotype. 10. S 8 - 10, female allotype, lateral view.