Protosticta samtsensis, Gurung & Phan, 2023

Gurung, Mer Man & Phan, Quoc Toan, 2023, Description of Protosticta samtsensis sp. nov. (Odonata: Zygoptera: Platystictidae) from Samtse district, Bhutan, Zootaxa 5352 (1), pp. 137-144 : 138-142

publication ID	https://doi.org/ 10.11646/zootaxa.5352.1.5
publication LSID	lsid:zoobank.org:pub:3A7DEF13-AEE8-48C5-A281-69362CD3B3AE
DOI	https://doi.org/10.5281/zenodo.8412178
persistent identifier	https://treatment.plazi.org/id/03AA7D6E-FFE9-FFF4-FF74-736DFB7207CB
treatment provided by	Plazi
scientific name	Protosticta samtsensis
status	sp. nov.

Treatment

Protosticta samtsensis View in CoL sp. nov.

( Figures 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5 , 6A–D View FIGURE 6 )

Holotype. ♁ , Norgaygang gewog (Bara) (27.142670°N, 88.835 228°E, altitude 1,264 m a.s.l), Samtse District, southern Bhutan ( Fig. 1 View FIGURE 1 ), 12-viii-2022, Mer Man Gurung leg.

Paratype: ♀, same date, location, and collector as the holotype.

Type specimens deposition. The holotype ♁ and paratype ♀ will be deposited in NBC, Serbithang , Bhutan .

Etymology. The species epithet samtsensis is an adjective; based on the name of Samtse District, southern Bhutan from where the type specimens were collected.

Suggested common name. Bhutan Reedtail is the common name suggested for the species.

Description of male holotype.

Head ( Fig. 4A View FIGURE 4 ). Dark metallic green; mandibles, labrum, and labium are yellowish white (pale yellow in live individual); movable hooks and upper margin of labrum greenish black; genae brown. Anteclypeus, postclypeus, vertex, and basal segment of antennae black with green metallic sheen; last antennal segments dark brown, and ocelli brown. Eyes (in live individual) dark green upper half and light green below ( Fig. 2 View FIGURE 2 ); light brown when preserved.

Prothorax ( Fig. 4B View FIGURE 4 ) dorsally with broad pale yellow lateral stripe in live individual ( Fig. 2 View FIGURE 2 ) which turns creamy yellow when dried, pale stripe on anterior lobe separated by a black patch in the center, major portion of middle lobe black, which is square shaped with narrow extensions at the four corners, the black marking extends towards center of the posterior lobe which is spherical shaped; small prothoracic spines narrow, yellowish, pointed opposite and curved downward.

Pterothorax ( Fig. 3A View FIGURE 3 ). Dorsum deep metallic green with creamy yellow metepisternum stripe; lateral stripe oblique black with green metallic sheen; metepimeron and ventral surface pale yellow in live individual but turns creamy yellow when preserved ( Fig. 2 View FIGURE 2 ).

Legs ( Fig. 3A View FIGURE 3 ). Coxae pale yellow (live individual) and creamy yellow in dried specimen; trochanters yellowish with black posterior spot; femora yellowish; tibio-femoral joints and flexors blackish brown; tibiae yellowish; tarsus along with claws and spines dark brown.

Wings ( Fig. 5A View FIGURE 5 ) hyaline; Pt black, trapezoid shaped; postnodal crossveins FW-16 and HW-15.

Abdomen ( Fig. 3A View FIGURE 3 ) Blackish brown with creamy yellow markings as follows: S1–2 dark brown and creamy yellow at lateral lower half, S3–6 blackish brown dorsum which gets darker at the posterior end with dull yellow anterior end, S7 light brown with yellow basal end, S8 dorsum brown and venter yellowish throughout, S9 slightly yellowish-brown streaks covering 3/4 part in live individual but turns brown when preserved, S10 completely dark brown.

Anal appendages ( Fig. 7A–D View FIGURE 7 ) dark brown, in lateral view ( Fig. 7B View FIGURE 7 ) cercus strongly curved downwards, 2.5 times longer than S10, broad at the base, constricts and toward tip on the inner side broadening abruptly forming a depression then eventually narrowing to form a blunt tip, on the outer side, with a slight protrusion towards the tip. Paraprocts dark brown, longer than cerci, with broad base slightly directed towards cerci, towards tip constricted forming an acute angle in the inner side, which then broadens and terminates in a pointed tip directed slightly upwards. In dorsal view ( Fig. 7A View FIGURE 7 ) cerci curved inward, broad at base which then narrows and again becomes slightly broader and finally ends with blunt tip. In the ventral view ( Fig. 7D View FIGURE 7 ) paraprocts are strongly curved inward, broader at the base, which then constricts and has stout wedge shaped inward directed spines at around 3/4 length of the paraprocts, then it smoothly broadens in outward directed curve which forms a spoon-shaped tip. In dorso-oblique view ( Fig. 7C View FIGURE 7 ) cerci are strongly curved downward almost touching the paraprocts, tip of the spine on the paraprocts slightly lifted towards the cerci and paraprocts terminate in scoop-like structured tip.

Genital ligula ( Fig. 5C View FIGURE 5 ) simple structurally, the tip with two short apical flagella each slightly broader apically.

Measurements (in mm). HW 21; abdomen including appendages 40.

Description of female paratype. Looks similar to male with minute differences as follows:

Head ( Fig. 4C View FIGURE 4 ) labrum and upper half of the labium bluish-white and black below separated by thin faint brown margin. Mandibles black with brown at the corners, genae brown. Eyes dark green.

Prothorax ( Fig. 4D View FIGURE 4 ) anterior lobe with different black central marking, only posterior portion marked with black border.

Legs ( Fig. 3B View FIGURE 3 ) trochanter posterior dark spot absent.

Wings ( Fig. 5A View FIGURE 5 ) postnodal crossveins FW-17 and HW-15.

Abdomen ( Fig. 3B View FIGURE 3 ). S9 with lateral bright brownish yellow patch.

Anal appendages ( Fig. 6A–B View FIGURE 6 ) dark brown, broad at the base with smooth tip, slightly longer than S10 and bit curved downward. Ovipositor dark brown laterally with creamy yellow sharp spiky tip ( Fig. 6B View FIGURE 6 ).

Measurements (in mm). HW 27; abdomen including appendages 36.

Differential diagnosis. The genus Protosticta can be distinguished from Drepanosticta Laidlaw, 1917 by the absence of nervure ab ( Fig. 5A–B View FIGURE 5 ). Among representatives of the genus Protosticta found in the Indian subcontinent, two species, viz. P. samtsensis and P. himalaica can be distinguished from congeners by their robust paraprocts being longer than the cerci and bearing two inward directed spines ( Fig. 7A–I View FIGURE 7 ). The two species can be separated with the following diagnosis: cercus of P. himalaica with a dorsal inward-directed spine ( Fig. 7E, G View FIGURE 7 ) whereas the dorsal cercus of P. samtsensis is smooth, without spine ( Fig. 7A View FIGURE 7 ). In P. himalaica the paraprocts have a long inward directed narrow medial spine. However, in P. samtsensis the spine on the paraproct is much shorter, stouter, and wedge-shaped ( Fig. 7C, D View FIGURE 7 ). In other species known from the northeast of Indian subcontinent, the cerci of P. fraseri and P. damacornu are broad in apex, form a triangular plate (for instance, see Fig. 3 View FIGURE 3 in Terzani & Carletti (1998), while cerci of P. samtsensis and P. himalaica are narrow, and blunt at tip ( Fig. 7A, E View FIGURE 7 ). Moreover, unlike P. samtsensis and P. himalaica , the cercus and paraproct of both P. fraseri and P. damacornu are of equal length (for instance, see Fig. 2 View FIGURE 2 in Terzani & Carletti (1998)).

While the original description of Laidlaw (1917) is based on immature specimens, we provide the difference in body coloration between P. himalaica and P. samtsensis based on the description of P. himalaica in Laidlaw (1917) and Fraser (1933) and the specimens collected from Bhutan as follows: P. himalaica with pale brown labium; clypeus blue; and vertex black whereas P. samtsensis has whitish-yellow labium; anteclypeus, postclypeus, and vertex are metallic green. Pterothorax of P. himalaica with black dorsum and lateral stripe, pale blue above and below lateral stripe. In P. samtsensis pterothorax with dorsum and lateral stripe metallic green, creamy yellow above and below a lateral stripe. The abdomen of P. himalaica in live individual S1 has blue sides with a white apical ring, S2 laterally blue marked with a blue dorsal strip, but it is different in P. samtsensis S1–2 dorsum brown, lateral half creamy yellow. In P. himalaica S3 dorsum has white basal triangle which is missing in P. samtsensis . Furthermore, in P. himalaica , S7 apical half, S8–9 and S10 the basal end is blue in live individual but turns brown when preserved. In contrast P. samtsensis S7–8 are brown with yellowish venter and S9–10 complete brown. In female P. himalaica the ventro-lateral sides of S1–3 are bluish and S8 has a large lateral blue spot, while in P. samtsensis S1–3, including lateral S8 are brown ( Fig. 3B View FIGURE 3 ).

Habitat and ecology. Protosticta samtsensis inhabits moist, shady seepages with thick tree canopies and it was collected from 1,264 m a.s.l. Protosticta himalaica also occurs in similar habitat types within the elevation range of 350–1,500 m a.s.l in Bhutan. The new species was observed taking short flights and devouring small flies. A male and a female were collected from the same habitat. The side vegetation was a mixed-broad-leaf forest with thick fern undergrowth. The stream called Seti Khola, meaning white stream, had a fast current. Along the sides, there was thick riparian vegetation and a spring that originated from the base of a cliff nearby fed into the stream. The forest floor has black soil with decomposed leaf litter, and it remains wet for most of the season.