Leptobasis linda, Johnson, Jim T., 2016

Johnson, Jim T., 2016, Leptobasis linda sp. nov. from Ecuador (Odonata: Coenagrionidae), Zootaxa 4171 (2), pp. 373-381 : 374-381

Leptobasis linda sp. nov.

Etymology. This species is named linda in honor of my wife Linda C. Pritchard and is to be treated as a noun in apposition. The meaning of this word in Spanish (“beautiful”) is also fitting for this attractive species that occurs in a predominantly Spanish-speaking country.

Specimens examined. Holotype: ♂ from a small forested stream N of Chindul, Manabí Province, Ecuador (00.2389° N, 079.8742° W), elevation approx. 30 meters asl , 1 March 2010, leg. JTJ ( FSCA) Allotype: ♀ from a small stream 1.8 km N of Hwy . 491, approx. 25 km E of Babahoyo , Los Ríos Province, Ecuador (01.8111° S, 079.3189° W), elevation approx. 60 meters asl, 7 March 2010, leg. JTJ ( FSCA) . Paratypes (Total: 18♂, 11♀): stream and associated pond, wetland about 12 km E of Arenillas, Hwy 25, El Oro Province, Ecuador (03.5244° S, 079.9831° W), elevation approx. 30 meters asl , 29 March 2008 (2♂, 1♀ leg. KJT, 2♂, 1♀ leg. JTJ), 9 April 2008 (2♂ 1♀ leg. KJT); stream, 14 km S of Arenillas , rd. to Alamar, El Oro Province, Ecuador (03.6655° S, 080.0869° W), elevation approx. 85 meters asl , 10 April 2008 (1♂ leg. KJT); ditches/pools 2.8 km E of Hwy E 25 (from km marker 98), Los Ríos Province, Ecuador (01.5217° S, 079.5000° W), elevation approx. 35 meters asl , 21 February 2010 (1♂ leg. JTJ, 1♂ leg. KJT); stream 16 km E of Hwy E 25 (from Formisa), Los Ríos Province, Ecuador (00.7256° S, 079.3483° W), elevation approx. 200 meters asl , 23 February 2010 (1♀ leg. JTJ); borrow pit/small slow stream, NW of El Carmen, Manabí Province, Ecuador (00.1375° S, 079.5728° W), elevation approx. 185 meters asl , 28 February 2010 (1♂ leg. KJT, 1♀ leg. JTJ); small stream about 2 km E of Pedernales , Manabí Province, Ecuador (00.0836° N, 080.0139° W), elevation approx. 90 meters asl , 28 February 2010 (1♂ leg. JTJ); same as holotype (2♂ leg. KJT, 2♂ leg. JTJ); same as allotype (1♂, 1♀ leg. JJD, 2♀ leg. KJT, 1♀ leg. JTJ); small stream 2.4 km N of Hwy 491, approx . 25 km E of Babahoyo , Los Ríos Province, Ecuador (01.8117° S, 079.3242° W), elevation approx. 55 meters asl, 7 March 2010 (2♂ 2♀ leg. JTJ).

The holotype, allotype, and 2 paratypes have been deposited in the FSCA. Paratypes have also been deposited in the UMMZ, NMNH, and the collections of JTJ, KJT, JJD, DRP, RWG, and TWD.

Additional material: 113 specimens (44♂, 69♀ leg. Wm C. MacIntyre), most in fragmentary or otherwise poor condition, in 62 triangles marked with “PLAYAS” or “Prov. de los Ríos ” and various dates in March and April 1938 ( UMMZ).

Holotype. Head. Labrum, base of mandible, and anteclypeus pale green; labrum with narrow dark brown coloration along lateral margins, becoming black adjacent to anteclypeus; postclypeus black with pale green border (narrowest anteriorly, widest laterally). Frons rounded. Dorsum of head black except for pale green areas as follows: genae, extending dorsally along eye margins to level near antennal bases and medially as a narrow band adjacent to postclypeus; acutely triangular postocular spots extending anteriorly along margin of each eye; occipital bar; small triangular patch on vertex, its base vaguely demarcated from occipital bar and extending to a point between lateral ocelli ( Fig. 1). Pale green postocular spots extending posteriorly and ventrally to genae; area bordering occipital foramen black.

Thorax. Pronotum black except for pale green areas as follows: propleuron, not reaching notopleural suture; anterior lobe medially, widest anteriorly, a central quadrate spot on middle lobe bisected medially by a narrow black line. Hind lobe of pronotum entire, weakly trilobed, tapering laterally without projections; a narrow medial spot on posterior margin. Pterothorax black dorsally with pale green antehumeral stripes slightly narrower than black humeral stripes; antehumeral and humeral stripes relatively uniform in width throughout; mid-dorsal stripe approximately equal in width to combined antehumeral and humeral stripes; a narrow line of black extending along antealar carina connecting mid-dorsal stripe to dorsal edge of humeral stripe, thus isolating posterior end of antehumeral stripe from antealar carina. Sides of pterothorax pale green adjacent to humeral stripe becoming yellowish green ventrally; green extending dorsally as a narrow projection along antealar carina to humeral suture, thus isolating that portion of humeral stripe below humeral suture from antealar carina; indistinct short, brownish streak at metapleural fossa; posterior edge below metapleural carina edged with black. Venter of pterothorax entirely creamy yellow. Legs mostly pale cream with black armature; pretarsus with a narrow dark brown band adjacent to claw; claws with vestigial supplementary tooth. Left metafemur with six spurs, right with five, gradually increasing in length from proximalmost to distalmost and shorter than intervening spaces; metatibial spurs shorter than intervening spaces. Wings hyaline with brown veins; pt brown, rhomboidal, covering slightly less than one cell. Px 9 in both FW, 8 in both HW.

Abdomen. S1–2 reddish orange dorsally, becoming pale yellow ventrally; S1 with a narrow, black, ventromedial streak extending from base to approximate middle of sternite; vesica spermalis black with yellowishorange ventromedial stripe of irregular width; S3 dorsally reddish orange basally becoming glossy black distally, the black extending laterally and ventrally as an incomplete apical ring; S4–6 black dorsally, pale yellow ventrally, the dorsal black narrowing to a point anteriorly and extending laterally and ventrally to an incomplete apical ring on each segment; S7 black dorsally on anterior half, becoming reddish orange on posterior half and yellowish orange ventrally; S8–10 reddish orange dorsally, yellowish orange ventrally; S7 and S8 sternites each with a narrow dark-brown mid-ventral line. Dorsoposterior margin of S10 with a weakly developed median cleft but not forming a prominent process. Cercus orange dorsally and laterally, dark brown to black medially; oriented dorsoapically when viewed laterally, wedge-shaped and divergent when viewed dorsally; ventral basal projection of cercus directed ventromedially; a slightly recessed pad present near tip of ental surface; remainder of ental surface strongly concave; cercus subequal in length to S10 measured dorsally; basal width about equal to lateral length. Paraproct yellowish orange, broadest basally, narrow and oriented posteriorly for most of length, about 1.6× length of cercus; viewed laterally, somewhat sinuous, curving slightly dorsally at about mid-length, then posteriorly; viewed ventrally, paraprocts curving medially with tips directed ventromedially and armed with a small, black angular process oriented medially ( Fig. 2 ). Genital ligula distal segment with inner fold proximal to flexure and with two long basally directed sclerotized filaments appressed against ental surface not visible in lateral view; apical margin concave; lateral lobes lacking; ectal surface lacking fleshy papillae ( Fig. 3 ).

Measurements. Total length 33.5 mm; abdomen length 28.0 mm; Fw 17.0 mm; Hw 16.5 mm. Allotype. Head. Head color pattern similar to holotype.

Thorax. Pronotum color pattern similar to holotype except for a small medial pale green spot on dorsal surface of hind lobe adjacent to posterior margin; posterior margin continuous, lacking a supplementary inferior lobe, nearly straight (very slightly concave) medially, joining lateral margins at broadly obtuse angles. Pterothorax color pattern similar to holotype. Mesostigmal plates rounded laterally, with low dorsal triangulate ridges; high points of the triangulate ridges in line with transitions between black mid-dorsal and pale antehumeral stripes ( Fig. 4 ). Legs and wings as in holotype except: left metafemur with five spurs, right with seven. Fw Px 9, Hw Px 8.

Abdomen. Color pattern similar to holotype except for following differences: dorsal reddish orange on S3 limited to anterior one-fifth of segment, remainder black dorsally; dorsal black on S7 limited to anterior one-fourth, narrowing posteriorly, dorsal surface otherwise reddish orange. S7–8 sternites with darker mid-ventral stripes, one on S8 quite prominent and vaguely rhombus-shaped, its greatest width about one-third its length ( Fig. 5). Poorly developed vulvar spine present on S8. Ovipositor valves extending posteriorly beyond tips of cerci by a length subequal to the cerci; their dorsal surface nearly linear ( Fig. 6).

Measurements. Total length 35.0 mm; abdomen length 29.0 mm; FW 19.5 mm; HW 18.5 mm.

Variation in paratypes. Several of both sexes either lack the pale green triangle anterior to the occipital bar or it is reduced as an ill-defined spot. Three males with black on S7 restricted to proximal one-quarter while on six females S7 is nearly all black except for a narrow band of orange at distal end.

Four paratypes (3♂ 1♀) from 12 km E of Arenillas, El Oro Prov., 29 March 2008, are immature. Corresponding black areas on the head and thorax of mature individuals are orange. Postocular spots vary from lacking (undifferentiated from remainder of head dorsum) to ill-defined or well-defined pale blue. The pale antehumeral stripe is pale bluish green and another similar poorly defined stripe is adjacent to the ventral edge of the dark humeral stripe.

Measurements. Males, including holotype (n = 19): total length 32.5–36.0 mm (mean 34.4 mm); abdominal length 27.0–30.0 mm (mean 28.7 mm); Fw length 16.0– 18.5 mm (mean 17.4 mm); Hw length 15.5–17.5 mm (mean 16.5 mm). Females, including allotype (n = 12): total length 31.5–37.0 mm (mean 34.1 mm); abdominal length 26.0–31.0 mm (mean 28.2 mm); Fw length 17.5–20.0 mm (mean 19.0 mm); Hw length 16.5–19.0 mm (mean 17.9 mm). Among males and females, Fw Px usually 9 and Hw Px usually 8. Male paratypes display more variation in postnodals than females. Male Fw Px range 7–12 (1 with 7 Px on one Fw, 3 with 8 Px on one Fw, 1 with 8 Px on both Fw, 1 with 10 Px on one Fw, 3 with 10 Px on both Fw, and 1 with 12 on one Fw); male Hw Px range 6–9 (1 with 6 Px on both Hw, 5 with 7 Px on one Hw, 3 with 7 Px on both Hw, 1 with 9 Px on one Hw). Female Fw Px range 9–10 (2 with 10 Px on one Fw, 1 with 10 Px on both Fw); female Hw Px range 7–9 (1 with 7 px on one Hw, 1 with 9 Px on one Hw).

Appearance in life. Eyes of mature males and females mostly pale green below and sharply demarcated with black above on upper quarter ( Fig. 7 a,b). Eyes of immatures with upper quarter pale grayish white adjacent to a band of orange; lower half pale grayish-white ( Fig. 7 c). Pale grayish-white areas becoming blue-green with an orange-brown band on older immatures.

Diagnosis. The male caudal appendages of Leptobasis linda are most similar to the allopatric L. candelaria Alayo, 1968 , and L. melinogaster González-Soriano, 2002 , in that the strongly medially curved paraprocts are much longer than the cerci; however, the cerci and genital ligula differ from both, and L. linda lacks the unusual metafemoral spines characteristic of L. candelaria . The acutely triangular postocular spots and general coloration further differentiate male L. linda from both L. candelaria and L. melinogaster .

The ovipositor of Leptobasis linda is similar to those of the majority of known Leptobasis in that the dorsal margin is nearly linear in lateral view, but the posterior margin of the prothorax is unique in its combination of characters: continuous, lacking a supplementary inferior lobe, nearly straight (very slightly concave) medially, and joining the lateral margins at broadly obtuse angles (rather than evenly rounded).

Leptobasis vacillans Hagen in Selys, 1877 , is the only congener known to be sympatric with L. linda . The overall coloration of both is superficially similar except that the former has a greater extent of reddish orange on the base of the abdomen. Males are easily differentiated by the caudal appendages—particularly the shape of the paraprocts and their length relative to the cerci ( Fig. 8 ). Additionally, the median cleft on the dorsoposterior margin of S10 is much more developed and raised into a prominent dorsal process on L. vacillans , unlike the poorly developed median cleft of L. linda . Females of both species are similar structurally, although they differ by the posterior margin of the prothorax (evenly rounded on L. vacillans ; more angular on L. linda ). The black mark on the sternite of S8 on females differs: roughly rhombus-shaped on L. linda with its greatest width about 1/3 the length; restricted to a narrow line on L. vacillans (D.R. Paulson, pers. comm.). L. linda averages larger than L. vacillans (compared with measurements in Garrison & von Ellenrieder 2010), but the ranges overlap.

Distribution, habitat and biology. Leptobasis linda is thus far known only from Ecuador in the western provinces of El Oro, Los Ríos, and Manabí, but it is probably more widespread across the Pacific lowlands of the country and may also occur in Peru and Colombia ( Fig. 9 ). Habitats include small, low-gradient streams under or near forest cover, grassy marshes associated with small streams, and shallow forest pools. Elevation ranges from approximately 200 meters asl to below 100 meters asl where the species was more frequently encountered.

At a stream-associated marsh about 12 km east of Arenillas, El Oro Province, on 29 March 2008, large numbers of teneral Leptobasis linda were encountered in dense emergent grasses while few mature individuals were found. On a return visit to this site on 9 April 2008, tenerals were not seen, but several mature individuals were collected. Other Zygoptera found here included Neoneura confundens Wasscher & van’t Bosch, Lestes forficula Rambur , Acanthagrion trilobatum Leonard , Enallagma novaehispaniae Calvert , Telebasis brevis Bick & Bick , T. inalata Calvert , Ischnura fluviatilis Selys , Argia inculta Hagen in Selys , and A. oculata Hagen in Selys.

Additional sites where multiple Leptobasis linda were encountered included a small forested stream 0.5 km north of Chindul, Manabí Province, on 1 March 2010 and on a small stream 1.8 km and 2.4 km north of Hwy 491, about 25 km east of Babahoyo, Los Ríos Province, on 7 Mar 2010. Additional Zygoptera found on 1 March 2010 included Argia oculata , A. pulla Hagen in Selys , Psaironeura angeloi Tennessen , and Protoneura amatoria Calvert. Those found on 7 March 2010 included Protoneura amatoria and Neoneura confundens .

Only one or two individuals of Leptobasis linda were found at the remaining sites in 2008 and 2010. At a small stream and borrow pit northwest of El Carmen, Manabí Province, on 28 February 2010, a single teneral L. vacillans was collected, and thus far this represents the only known site of sympatry with L. linda .

Figures

FIGURE 2. Caudal appendages of Leptobasis linda holotype, lateral view (a) and dorsolateral view from slightly posterior angle (b).

FIGURE 4. Prothorax and mesostigmal plates of Leptobasis linda allotype, dorsal view.

FIGURE 7. Adults of Leptobasis linda: mature male paratype (a), small stream 0.5 km N of Chindul, Manabí Prov., Ecuador, 1 March 2010; mature female paratype (b), small stream 2.4 km N of Hwy. 491, ca. 25 km E of Babahoyo, Los Ríos Prov., Ecuador, 7 March 2010; immature male (c), 12 km E of Arenillas, El Oro Prov., Ecuador, 9 April 2008.

FIGURE 8. Caudal appendages of Leptobasis vacillans, lateral view (a) and dorsolateral view from slightly posterior angle (b).

FIGURE 9. Distribution of Leptobasis linda.

FIGURE 3. S 2 and genital ligula of Leptobasis linda holotype, lateral view (a); separated terminal segment, ectal and ventroental views (b). The ectal view of the terminal segment includes the pair of long, basally directed filaments, although they are on the ental surface.