Sulcosticta fliedneri Phan, Keetapithchayakul & Digma, 2025, sp. nov.

Sulcosticta fliedneri sp. nov. (Figures 2–6, 8A, 9A–B) Holotype. 1 ♂, Sitio Tabi stream (15.25326° N, 121.39115° E, 65 m a.s.l.), Dingalan Aurora, Aurora Province, Luzon, Philippines, 14.iii.2025, Q.T. Phan leg. Paratypes. 8 ♂♂, 5 ♀♀, same data as the holotype; 6 ♂♂, 4 ♀♀, Purok stream (15.25164° N, 121.39173° E, 84–170 m a.s.l.), Sitio Setic Barangay Ibona, Dingalan Aurora, Aurora Province, Luzon, Philippines, 15.iii.2025, Q.T. Phan leg. Specimens deposition. Holotype and two males, two female paratypes will be deposited in the Entomological Collection of Cavite State University, Philippines. Remaining paratypes are deposited in the Zoological Collection of Duy Tan University (ZCDTU), Danang city, Vietnam. Etymology. Species epithet “ fliedneri ” is a noun in genitive case. It is dedicated to Heinrich Fliedner, Bremen, Germany, who has been explaining the scientific names of dragonflies since 1997. In the meantime, numerous publications have appeared, often in co-authorship with the late Ian Endersby or Matti Hämäläinen, in which he applies his extensive knowledge of Latin and Greek, his broad historical knowledge and an extremely careful and meticulous approach to scientific facts to give a reliable, correct and consistent explanation of the origin of the names. In countless descriptions of dragonflies recognized as new to science, he has been consulted as the authority on correct naming to avoid grammatical or other errors. Therefore, this new dragonfly species is dedicated to Heinrich Fliedner in gratitude for his tireless support to the odonatological community. Heinrich is a philanthropist who richly endows all dragonfly enthusiasts with his knowledge and commitment. Description of holotype Head (Figs 2A, 3A–B). Frons dark brown; labrum pale blue with narrow yellowish distal margin; anteclypeus pale; postclypeus black. Genae dull blue. Antennae dark yellowish. Scape and pedicel yellow; flagellum black. Rest of head black. Eyes shining green in a live individual (Fig. 9A). Prothorax (Fig. 4A–C). Dull yellow with dorsal black spot. Anterior pronotal lobe short and rounded, slightly raising upward; median pronotal lobe elevated; posterior pronotal lobe bilobed, sharply dorsoposterior; lateral lobes angular, with undulating border and deep median cleft. Synthorax (Fig. 3B–C). Dark metallic green; dorsum brown with faint antehumeral area; mesepisternum unstriped; lateral sides dull yellow. Legs pale with darker femoral and tibial bands; tibial spines present. Wings (Fig. 2A, consult Fig. 5). Hyaline; venation brown; pterostigma rectangular, black with inner yellowish line; 10–11 postnodal crossveins; anal bridge absent. Genital ligula (Fig. 6A–B). Strongly bifid; each lobe recurved laterally and tapering apically; inner margins bear small spiniform denticles. Abdomen (Fig. 2A). Uniformly dark brown, whitish marking in anterior part of S3–7, but this marking pale blue in living adult (Fig. 9A); S1–2, posterior half S7 and S8–10 black; S7–10 broader than the other segments. Anal appendages (Fig. 7A, C, E, G) as the length of S10. Cerci short and robust, strongly curved dorsad in lateral view; apical margin with a small prominent tubercle. Paraprocts similar to cerci in length, yellowish except for apical part shining black; distally flattened and acutely curved anterodorsal. Measurements (in mm). Hindwing: 18; abdomen (including anal appendages) 26. Description of female paratype (Figs 2B, 3D–F, 4D–F, 7E–H). Similar to male in coloration, venation and prothoracic structure except as follows: Prothorax. Posterior lobes lower and more rounded; lateral lobes less prominent. Abdomen. Slightly stouter than in male; cerci short and triangular, entirely yellowish; ovipositor not surpassing cerci. The marking on S7 is white in the described specimen (Fig. 2B) but pale bluish in the living adult (Fig. 9B). Measurements (in mm). Hindwing: 18; abdomen (including appendages) 26. Variation in male and female paratypes. Other paratypes show little variation with the holotype male and paratype female used for the description in this paper. Differential diagnosis Among the genus Sulcosticta, the new species is allied to S. vantoli by the similarity in the structures of appendages and differs from other species by the paraprocts having a simple acutely curved tip (Fig. 8A–B). Between these two species, S. fliedneri can be distinguished from S. vantoli by (1), the cerci of S. fliedneri have small dorsal tubercles (Fig. 8A) versus smooth cerci in S. vantoli (Fig. 8B); in S. fliedneri, the cerci are broader (in lateral view), rounded and touching the paraprocts apically (Fig. 8A), versus bifurcate and well separated in S. vantoli (Fig. 8B). It should be noted that, paraprocts of S. viticula also have a curved tip, but a more complicated curled structure as per their description: “a subterminal, stoutly built process directed axiad, then posteriad, the tip brownish black and turned abaxiad” (van Tol 2005: p. 275). Habitat and biology. Specimens were collected from shaded steep forest streams with trickling water and dense riparian vegetation (Fig. 10A–B). Their behavior and microhabitat preferences align with those of other Philippine Sulcosticta species. In the field, the tip of the abdomen of the male and female of S. fliedneri is turned dorsad as in Fig. 9A–B. It may be a character for this genus (van Tol., per. comm.). Distribution. Philippines (Luzon, Dingalan Aurora, Aurora Province) (Fig. 1).