Phyllogomphoides bifasciatus (Hagen in Selys, 1878)

Torres-Pachón, Mónica, Novelo-Gutiérrez, Rodolfo & Ruiz-Sanchez, Eduardo, 2019, A synopsis of Phyllogomphoides Belle, 1970 (Odonata: Gomphidae) of Mexico: taxonomy and distribution, Zootaxa 4634 (1), pp. 1-67 : 17-19

Phyllogomphoides bifasciatus (Hagen in Selys, 1878)

Gomphoides bifasciata Hagen in Selys, 1878: 663 –664 [Bulletin de l’ Académie royale de Belgique (2) 46] (♀) Phyllogomphoides bifasciatus . Donnelly (1979: 253) [Odonatologica 8 (4)] (♂)

Phyllogomphoides bifasciatus . Ramírez (1996: 144–146) [Odonatologica 25 (2)] (larvae ♂, reared)

Type. Allotype 2♂♂: Guatemala, Izabal, Lago Izabal at mouth of Rio Polochic , 2 June 1978, T. Donelly leg. ( FSCA). (Material examined).

Type repository. Institut Royal des Sciences Naturelles de Belgique ( IRSN). (Not examined) .

Material studied: Total specimens: 3♂♂, 3♀♀, distributed like thus: 3♂♂, 2♀♀ ( FSCA), 1♀ ( IEXA). MEX- ICO: Chiapas; 15.0 mi. NW & 4.1 mi. W Tapachula , 28 July 1965, D. Paulson leg., 1♀ ; forest edge 41.4 mi., SE Pijijiapan , 23 June 1966, D. Paulson leg., 2♂♂, 1♀ ; Municipio Trinitaria, Lagos de Montebello , 19 June 2005, A. Niño leg., 1♀ . Oaxaca; canal 24.7 mi. WNW Tehuantepec , 3 August 1965, D. Paulson leg., 1♂ .

Description of male. Body brown to dark brown, with three pale stripes on pterothorax, usually second antehumeral and metepisternal stripe incomplete or absent.

Head: Face brown; labium and submentum pale to light brown; labrum brown, with lateral border light brown; mandibles pale basally, tips reddish-brown; anteclypeus creamy pale superiorly, postclypeus brown completely; lower and upper surface of antefrons brown, postfrons mostly pale, a tiny blackish-brown stripe at the union with vertex; antennal scape and pedicel dark brown with apical rim creamy pale; flagellum light brown to brown; vertex dark brown, depressed area between ocelli with a large, quadrate pale spot; occiput dark brown with a large, trapezoid, central pale spot, posterior border fringed with long, stiff, reddish-brown setae ( Fig. 19 ).

Thorax: Pronotum reddish-brown, with pale middorsal spot on anterior, middle and posterior lobes. Pterothorax reddish-brown, with three pale stripes and two stripes incomplete or absent as shown in Fig. 19 ; middorsal thoracic carina pale; antealar crest dark; first antehumeral stripe not connected to pale mesothoracic collar, forming an inverted “7” and reaching border of antealar crest superiorly; second antehumeral stripe absent and only a superior circular spot close to antealar crest; mesepimeral stripe broad, covering most of mesepimeron (90–95%) with parallel sided; metepisternal stripe absent or sometimes is discontinue and very thin, covering less than 15% of metepisternum’s length; metepimeral stripe forming and inverted “L” slightly reaching subalar carina; metaposternum pale; pectus brown. Legs: Femora brown, distally dark reddish-brown, anterior femora broadly pale ventrally, sometimes 3/4 of length of femora; tibiae reddish-black, armature black; tarsi and pretarsal claws reddish-black. Wings: Hyaline, tinged with light brownish at extreme base, venation black, anterior margin of costae with a continuos well-defined yellow line in all the wing; second primary antenodal crossvein the 8th (left), the 7th (right) in FW, the 7th (left), the 8th (right) in HW; antenodal crossveins FW 20–23, HW 15–17; postnodal crossveins FW 13–16, HW 14–15; triangles 2–3-celled; subtriangles 2-celled; supratriangles 2-celled; anal triangle 4-celled; pterostigma dark brown.

Abdomen: Reddish-brown on S1–2, black on S3–7, S8–10 black brown on dorsum. Pale coloration creamy ye- llow as follows: a middorsal stripe and the ventral 0.80–0.90 of tergum on S1; a middorsal stripe, auricles, and a posteroventral, narrow, vertical spot on S2; a middorsal stripe on basal 0.70–0.80 constricted at basal 0.85 of its length, and a broad basoventral spot on basal 0.30–0.40 of S3; a middorsal stripe on basal 0.70–0.80 tapering posteriorly, a slightly broad basoventral spot on basal 0.20–0.25 of S4; a middorsal stripe on basal 0.75–0.80 tapering posteriorly, a slightly broad basoventral spot on basal 0.15–0.20 of S5; a middorsal spot on basal 0.10–0.15, a slightly broad basoventral spot on basal 0.15–0.20 of S6; basal half of S7 and sometimes more 70–80% length of S7; S8 with pale strikes on basoventral 0.10; S9 and S10 without pale spots. Foliation on S8–9 moderately developed, that on S8 increasing gradually in width caudally, maximum width of foliation 0.15–0.20 mm, its edge with a row of small spines on apical 0.10 of its length; foliation on S9 of the same width along the entire margin, 0.10–0.15 mm wide, the edge smooth ( Fig. 32 ). Accessory genitalia: Anterior lamina thick, entire, anterior margin almost straight; in ventral view anterior hamuli tumid anteriorly, apically cleft forming two subequal branches, internal branch ending in a short blunt tip, external branch ending in a short incurved hook directed dorsomesally, with a with a large, semicircular, excavate area on external surface, mesal margin entire and almost straight; posterior hamuli subcylindrical, its inner edge convex to straight, ending in a short, thick, blunt tip directed mesally, sometimes little visible, with abundant long and short brown hairs ( Figs. 47–48 ). Vesica spermalis : V1 bifid with a large tooth on midddle, V2–3 usual type, V4 with 2 relatively short flagella not reaching posterior margin of V1. Caudal appendages: Cerci, with abundant long setae, dorsally pale on apical 0.40–0.50 its length, basal 0.50–0.60, ventral surface, and apices black brown, a dorsomesal tooth with a sharp tip 0.34–0.40 mm length at basal 0.60–0.70 directed medially, followed distally by a medial, subapical, shelf-like carina, tips slightly flatenned laterally and produced dorsally into a stout spine; in lateral view tip of cercus strongly produced dorsally in a large and wide spine, no ventral spine on tip. Epiproct pale with brown tips dorsally, V-shaped, tips sharp, separated from each other by a distance of 0.80–0.86 mm; in lateral view branches slightly up-curved ( Figs. 75–77 ).

Measurements: TL, 56.61; AL, 41.50; FwL, 34.66; HwL, 32.66; FwW, 7.26; HwW, 9.01; cerci length, 2.86.

Female. Similar to male, with the following differences: Head: labrum brown completely, without pale spots; mandibles pale basally and half to tips reddish-brown; anteclypeus pale with a light brown band superiorly; occiput dark brown with a small to medium, circular, central pale spot. Thorax: Metaposternum light brown and sometimes with a small pale spot posteriorly. Wings: Sometimes anterior margin of costae light brown; antenodal crossveins FW 21–23; postnodal crossveins HW 13–16; supratriangles 2 or 3-celled; anal triangle 5 or 6-celled. Abdomen: A middorsal stripe and the ventral 0.5–0.6 of tergum on S1; a posteroventral, width, vertical spot occuping 0.7–0.9 posteriorly on S2; a middorsal stripe on basal 0.95–1.0 constricted at basal 0.85 of its length, and a broad basoventral spot on basal 0.25–0.35 of S3; a middorsal stripe on basal 0.85–0.95 tapering posteriorly, a slightly broad basoventral spot on basal 0.25 of S5; a middorsal spot on basal 0.40–0.50, a slightly broad basoventral spot on basal 0.15–0.25 of S6; basal half of S7 or less. Foliation on S8–9 very tiny, foliation on S8 with the edge with a small row of small spines on apical 0.10 of its length, maximum width of foliation 0.10 mm; foliation on S9 sometimes seems absent, 0.07 mm wide or less, inferior margin smooth ( Fig. 110 ). Vulvar lamina: Small, occupying 0.15 the length of S9; in ventral ( Fig. 123 ) view widely U-shaped, lobes triangular, black, with the apex widely rounded, the most ventral margin reddish-black and beset with stiff yellowish-brown setae, tips separated each other by a distance shorter than the basal width of each lobe; dorsal margin straight with a blunt tubercle on posterior corner and directed dorsally; in lateral view ( Fig. 124 ). Caudal appendages: Cerci long, conical, sharply pointed, longer than S10 ( Fig. 110 ), light yellow, with abundant long setae. Epiproct brown, laminar-shape ending amply rounded at the tip, directed ventrally; in ventral and dorsal views with few, short, whitish hairs and sometimes the epiproct little visible dorsally.

Measurements (average in parenthesis): TL, 57–58.33 (57.66); AL, 40–42 (41); MWh, 8.0; FwL, 37–38 (37.66); HwL, 36–37 (36.5); FwW, 7.5–9.0 (8.16); HwW, 9.37–10.5 (9.91); HfL, 6.4; VlL, 0.30–0.34 (0.32); cerci length, 2.33–2.36 (2.34).

Comparative diagnostic notes. This species closely resembles P. duodentatus . Both species are from small to medium size. Males can be differentiated from P. duodentatus by the following (features of the later parentheses): cercus with one dorsomesal tooth (cercus with two dorsomesal teeth); pterothorax with three pale stripes and cercus with one dorsomedial tooth (pterothorax with five pale stripes and cercus with two dorsomesal teeth). Females have three pale stripes on pterothorax (females have five pale stripes on pterothorax). On the other hand, the geographic distribution pattern of P. bifasciatus is towards the south of the Gulf of Mexico, while in P. duodentatus it is more towards the center and south of the Gulf of Mexico. Similarily, P. bifasciatus can be separated from other species by the external surface of posterior hamulus rounded (external surface of posterior hamulus keeled at tip [ P. pugnifer ], posterior hamulus strongly expanded at middle, tapering posteriorly ending in a stout, sharply pointed hook [ P. nayaritensis ]. Anterior hamulus with mesal margin entire, with the apex cleft forming two subequal branches with a similar shape (anterior hamulus with mesal margin notched or broadly emarginate, the tip widely rounded or narrowly hooked [ P. apiculatus , P. danieli , P. enriquei , P. indicatrix , P. luisi , and P. pacificus ]. Anterior hamulus with mesal margin entire, with the apex cleft forming two subequal branches with a similar shape (mesal margin and apex entire [ P. suasus ]. And from the remaining species by abdominal segments S8–10 mainly black (abdominal segments 8–10 brown with extensive yellow or orange [ P. albrighti and P. stigmatus ].

Flight season. June, July, and August.

Distribution. Chiapas, Jalisco, Oaxaca ( Fig. 143 ). In other countries: Costa Rica, El Salvador, Guatemala, Honduras, and Nicaragua ( Paulson & Gozález-Soriano 2018).

Natural history. The habitats of this species are small streams in semi-forested areas to larger streams and small rivers ( Donnelly 1979). The larvae of Phyllogomphoides bifasciatus “live in a creek that runs through secondary forest. Usually, the zones that are characterized for reduced flow and muddy bottoms are favorable for larvae. Some of the creek shores were covered with grasses and secondary vegetation” ( Ramírez 1996). According to the records, this species has an altitudinal distribution in Mexico from 61 to 1500masl.

Figures

FIGURES 17–22. Head and thorax, lateral view. 17) P. albrighti, male; 18) P. apiculatus, male; 19) P. bifasciatus, female; 20) P. danieli, male; 21) P. duodentatus, male; 22) P. enriquei, male.

FIGURES 30–36. Abdominal segments S8–10 and caudal appendages, left lateral view. 30) P. albrighti, male; 31) P. apiculatus, male; 32) P. bifasciatus, male; 33) P. danieli, male; 34) P. duodentatus, male; 35) P. enriquei, male; 36) P. indicatrix, male (alcoholic teneral specimen).

FIGURES 43–52. Male accessory genitalia, ventral and ventrolateral view. 43–44) P. albrighti; 45–46) P. apiculatus; 47–48) P. bifasciatus; 49–50) P. danieli; 51–52) P. duodentatus.

FIGURES 69–83. Male caudal appendages, dorsal, lateral and ventral view. 69–71) P. albrighti; 72–74) P. apiculatus; 75–77) P. bifasciatus; 78–80) P. danieli; 81–83) P. duodentatus.

FIGURES 108–113. Female abdominal segments S8–10 and caudal appendages, left lateral view. 108) P. albrighti; 109) P. apiculatus; 110) P. bifasciatus; 111) P. danieli; 112) P. duodentatus; 113) P. luisi.

FIGURES 119–130. Female vulvar lamina, ventral and ventrolateral view. 119–120) P. albrighti; 121–122) P. apiculatus; 123–124) P. bifasciatus; 125–126) P. danieli; 127–128) P. duodentatus; 129–130) P. luisi.

FIGURES 143–144. Maps of geographical distribution. 143) P. bifasciatus; 144) P. danieli.