Wormaldia nui, Johanson & Pham, 2025

Johanson, Kjell Arne & Pham, Hong-Thai, 2025, Description of three new species of Wormaldia McLachlan, 1865 from Vietnam (Trichoptera: Philopotamidae), European Journal of Taxonomy 1007, pp. 24-34 : 30

Wormaldia nui sp. nov.

urn:lsid:zoobank.org:act:CB2E57C6-4B85-4619-8D95-F40DC1A02ECB

Figs 1 , 3 , 9–12

Diagnosis

The male genitalia of Wormaldia nui sp. nov. closely resemble those of Wormaldia muoibon , particularly in lateral view, where the harpagones are almost straight and parallel-sided, and of equal length as the coxopodites.Additionally, tergite VIII is produced above segment IX. However, W. nui is distinguishable from W. muoibon based on several male genital features: in W. nui , the harpagones are parallel-sided in ventral view, whereas they slightly taper in W. muoibon ; further, the phallus of W. nui has two short, straight sclerites at the posterior end, in contrast to the three longer, straight sclerites found in W. muoibon .

Etymology

Wormaldia nui sp. nov. was named after the Nui Pia Oac Nature Reserve, the type locality of the species.

Type material

Holotype VIETNAM • ♂ (in alcohol); Cao Bang Province, N Nui Pia Oac Nature Reserve, about 9.5 km (rd) N of Phia Dén Village, 100 m upstream of bridge; 10 Apr. 2012; Johanson and Pham leg.; light trap at stream with mixed stream bottom; loc#VN028; VNMN.

Paratype VIETNAM • 1 ♂ (in alcohol); Cao Bang Province, Nui Pia Oac Nature Reserve , about 200 m downstream on rd to radio tower; 10 Apr. 2012; Johanson and Pham leg.; light trap at village center; loc#VN030; NHRS .

Description (holotype)

Forewing ( Fig. 3 ) 4.5 mm (N = 1), membrane light brown, veins dark brown. Forks 1–5 present; fork 1 originates shortly before distal corner of Dc; basis of M1+2 and Ms hyaline; arc located slightly distally of base of fork 5. Abdominal segments VII and VIII with long posteroventral lobes ( Figs 9, 11 ). In lateral view ( Fig. 8 ), segment IX forming triangular anteriorly, posteroventral corner not produced posteriorly; coxopodites with slightly convex ventral margin, dorsal margin strongly convex; harpagones straight, with almost parallel-sided dorsal and ventral margins, about as long as coxopodites, each with rounded apex. In dorsal view ( Fig. 10 ), segment IX with wide U-shaped anterior margin; tergum X with basal three-quarters with parallel-sided lateral margins, with two pairs of short setae before narrowing apex. In ventral view ( Fig. 11 ), with sternum IX with small central incision at posterior margin; basal twothirds of coxopodites fused, each with distal half of mesal margin straight, bearing few stout setae near posteromesal corner; harpagones almost straight, without mesal process. Phallus ( Fig. 12 ) with thin sclerites in group before mid-length and one pair of short, triangular sclerites situated close to each other near apex.

Figures

Fig. 1. A map of Vietnam with provinces; figures indicate the number of species of Wormaldia McLachlan, 1865 recorded in each respective province. The shading represents the species richness, with darker shading corresponding to a higher number of species recorded in that province.

Figs 2–4. Right forewing and hind wing of species of Wormaldia. 2. Wormaldia piadenensis sp. nov., holotype, ♂ (VNMN). 3. Wormaldia nui sp. nov., holotype, ♂ (VNMN). 4. Wormaldia caobangensis sp. nov., holotype, ♂ (VNMN).

Figs 9–12. Wormaldia nui sp. nov., ♂, holotype (VNMN). 9. Lateral view. 10. Dorsal view. 11. Ventral view. 12. Phallus, lateral view.

Figs 5–8. Wormaldia piadenensis sp. nov., ♂, holotype (VNMN). 5. Lateral view. 6. Dorsal view. 7. Ventral view. 8. Phallus, lateral view. Roman numbers relate to abdominal segment numbers.