Polyplocia nebulosa Goncalves & Peters, 2016

Kwanboon, Sedtawut, Boonsoong, Boonsatien & Suttinun, Chanaporn, 2023, Taxonomic review of the Oriental genus Polyplocia Lestage, 1921 (Ephemeroptera, Euthyplociidae), with two new records for Thailand, ZooKeys 1179, pp. 197-217 : 197

Polyplocia nebulosa Goncalves & Peters, 2016

Figs 2 , 3

Polyplocia nebulosa Gonçalves & Peters, 2016: 554, figs 1-21, original description (male and female imago, female subimago, egg, possible nymph).

Material examined.

Thailand: Two nymph in alcohol, deposited in ZMKU, Kanchanaburi province, Thong Pha Phum district, Pat Sadu Klang , 14°33'10.8"N, 98°33'94.3"E, 349 m, 20.II.2016, B. Boonsoong leg. Three nymphs in alcohol, deposited in ZMKU, Phetchaburi province, Kaeng Krachan district, Ban Krang river , 12°28'53.2"N, 99°15'23.0"E, 386 m, 11.II.2023, A. Vitheepradit leg.

Diagnosis.

Imago: i) wings with longitudinal veins light brown and cross veins brown, cross veins with narrow dark brown clouds and margins tinged with brown, ii) sterna II-IX with a pair of blackish brown anterolateral marks, iii) penes broad, T-shaped, fused, with medial groove extending from apex to half-length of penes; large laterally projecting lobes apically rounded with a small dorsolateral spine; basal outer margin of each lobe sclerotized, iv) styliger plate short and straight, not projected posteriorly, and v) eggs 265-267 μm in length and 170-186 μm in width, barrel shaped, without polar caps or other attachment structures, with one visible micropyle and chorion forming an irregular mesh with raised ridges, mesh size from 3.8-8.0 μm ( Gonçalves and Peters 2016). Nymph: i) larger spines on distal ½ of tusk, and ii) sterna with a pair of anterolateral black marks ( Gonçalves and Peters 2016).

Description.

Male imago. See Gonçalves and Peters (2016).

Female imago. See Gonçalves and Peters (2016).

Nymph. See Gonçalves and Peters (2016).

Additional description.

Mandibular tusks (Fig. 3E ) strongly arched inward (20.7° in curvature, for angle measurement see Kwanboon et al. (2021)). Labrum (Fig. 3A ): median concave with shallow emargination, with long and short setae on sub-basal, subapical and anterior margins. Hypopharynx (Fig. 3B ): lingua cordiform, superlingua slightly extended laterally with dense setae on distal margin. Labium (Fig. 3C ): paraglossae with dense setae on ventral margin, meet above glossae; glossae drop-shaped; palpi with long setae on outer margin; 3rd segment much broader, acutely rounded at the apex. Maxilla as in Fig. 3D : 1st segment with a few fine setae on outer margin; 2nd segment with long hair-like setae in both inner and outer margin; 3rd segment long, at least 2 × longer than 2nd segment, apically pointed with numerous long, hair-like setae.

Distribution.

Malaysia (Sabah), Thailand (Kanchanaburi, Phetchaburi).

Figures

Figure 2. Habitus of nymph of Polyplocia nebulosa: A dorsal view B ventral view.

Figure 3. Polyplocia nebulosa, nymphal morphology: A labrum (dorsal view) B hypopharynx (ventral view) C labium (ventral view) D left maxilla (ventral view) E mandibular tusk. Scale bar: 0.5 mm.