Wormaldia piadenensis, 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 : 28-30

Wormaldia piadenensis sp. nov.

urn:lsid:zoobank.org:act:A47E096C-BDC2-4038-97C3-82309676D9E3

Figs 1–2 , 5–8

Diagnosis

The male genitalia of Wormaldia piadenensis sp. nov. exhibit a notable similarity to those of Wormaldia muoihai , particularly in the presence of downwardly curving harpagones, which are of equal height at mid-length and at the base, and are each shorter than the coxopodites. However, W. piadenensis can be distinguished from W. muoihai by several key characteristics in the male genitalia: segment IX is shorter, segment IX possesses a distinct posteroventral process, the dorsal margin of the coxopodites is more sharply produced dorsally, and the phallus features a single posterior curved sclerite and a long, needleshaped anterior sclerite, in contrast to the two short, straight sclerites present in W. muoihai .

Etymology

Wormaldia piadenensis sp. nov. was named after Phia Dén Village, near 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.

Description (holotype)

Forewing ( Fig. 2 ) 5.5 mm (N = 1), membrane light brown, veins dark brown. Forks 1–5 present; fork 1 originates at distal corner of Dc; basis of M1+2 and Ms hyaline; arc located opposite to base of fork 5. Abdominal segments VII and VIII with long posteroventral lobes ( Figs 5, 7 ). In lateral view ( Fig. 5 ), segment IX anteriorly triangular and posteroventral part produced posteriorly; coxopodites with almost straight ventral margin, dorsal margin slightly produced into triangular; harpagones almost uniformly curving ventrad along their length, about ½× as long as coxopodites, each with rounded apex. In dorsal view ( Fig. 6 ), segment IX with wide U-shaped anterior margin; tergum X triangular, with few setae. In ventral view ( Fig. 7 ), with sternum IX produced into small, narrow triangle; basal half of coxopodites fused, distal half with irregularly shaped mesal margin bearing stout setae at posteromesal corner; harpagones almost straight, with small mesal process at mid-length. Phallus ( Fig. 8 ) with one pair of very short sclerites running along its length, and one sickle-shaped sclerite 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 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.