Description of Protosticta samtsensis sp. nov. (Odonata: Zygoptera: Platystictidae) from Samtse district, Bhutan Author Gurung, Mer Man College of Natural Resources, Department of Forest Science, Royal University of Bhutan Author Phan, Quoc Toan 0000-0002-3154-6546 The Center for Entomology & Parasitology Research, College of Medicine and Pharmacy, Duy Tan University, Da Nang, Vietnam pqtoan 84 @ gmail. com; phanquoctoan 1 @ dtu. edu. vn; https: // orcid. org / 0000 - 0002 - 3154 - 6546 pqtoan84@gmail.com text Zootaxa 2023 2023-10-02 5352 1 137 144 http://dx.doi.org/10.11646/zootaxa.5352.1.5 journal article 270810 10.11646/zootaxa.5352.1.5 0d2702de-5255-4f93-b43f-35d32ba1b042 1175-5326 8407019 3A7DEF13-AEE8-48C5-A281-69362CD3B3AE Protosticta samtsensis sp. nov. ( Figures 2–5 , 6A–D ) FIGURE 2. Protosticta samtsensis sp. nov. , holotype ♁ alive in the wild. FIGURE 3. Habitus of Protosticta samtsensis sp. nov. (A), holotype ♁ & (B), paratype ♀. Holotype . ♁ , Norgaygang gewog (Bara) ( 27.142670°N , 88.835 228°E , altitude 1,264 m a.s.l), Samtse District , southern Bhutan ( Fig. 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 ). 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 ); light brown when preserved. Prothorax ( Fig. 4B ) dorsally with broad pale yellow lateral stripe in live individual ( Fig. 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. FIGURE 4. Head and prothorax of Protosticta samtsensis sp. nov. (A, B), holotype ♁ & (C, D), paratype ♀. Pterothorax ( Fig. 3A ). 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 ). Legs ( Fig. 3A ). 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 ) hyaline; Pt black, trapezoid shaped; postnodal crossveins FW-16 and HW-15. Abdomen ( Fig. 3A ) 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 ) dark brown, in lateral view ( Fig. 7B ) 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 ) 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 ) 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 ) 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 ) simple structurally, the tip with two short apical flagella each slightly broader apically. FIGURE 5 . Wings and genital ligula of Protosticta samtsensis sp. nov. (A), wings holotype ♁; (B), wings paratype ♀; (C), genital ligula of holotype ♁. 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 ) 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 ) anterior lobe with different black central marking, only posterior portion marked with black border. Legs ( Fig. 3B ) trochanter posterior dark spot absent. Wings ( Fig. 5A ) postnodal crossveins FW-17 and HW-15. Abdomen ( Fig. 3B ). S9 with lateral bright brownish yellow patch. Anal appendages ( Fig. 6A–B ) 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 ). FIGURE 6. Anal appendages of Protosticta samtsensis sp. nov. , paratype ♀: (A) lateral view, (B) dorsal view. 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 ). 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 ). The two species can be separated with the following diagnosis: cercus of P. himalaica with a dorsal inward-directed spine ( Fig. 7E, G ) whereas the dorsal cercus of P. samtsensis is smooth, without spine ( Fig. 7A ). 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 ). 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 in Terzani & Carletti (1998) , while cerci of P. samtsensis and P. himalaica are narrow, and blunt at tip ( Fig. 7A, E ). 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 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 ). 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.