Hyadina scutellata ( Haliday, 1839 )

Stuke, Jens-Hermann, 2024, An identification key for the European species of Hyadina Haliday and a new interpretation of Hyadina vernalis (Robineau-Desvoidy), Spixiana 47 (1), pp. 49-62 : 58-60

Hyadina scutellata ( Haliday, 1839)

Hyadina (Hyadina) scutellata Haliday 1839: 406 ; type-locality: “ Hollywood ” [ Ireland]; no information available about type material [NMID, Mathis & Zatwarnicki 1995].

Unpublished material: CROATIA: 13, 25.vi.2017, Ðuračica 5 km s Magić Mala [45.133°N 17.596°E], leg. et coll. Stuke ; 13, 19.vii.2018, Šarena Jezero near Knin [44.027° N 16.223° E], leg. et coll. Stuke ; FINLAND: 13, 20.vii.2020, Northern Ostrobothnia, Iijoki n Kauppila [65.331° N 25.381° E], leg. et coll. Stuke ; GEORGIA: 1♀, 30.vi.2019, Debeda River n Kirach-Mughanlo [41.340° N 45.051° E], leg. et coll. Stuke.

Diagnosis. This species is easily recognised by the completely velvet black scutellum ( Fig. 6 ). It might be confused only with similar Nostima picta (Fallén, 1813) that also has a completely velvet black scutellum. However, N. picta has an arista with long rays (short in H. scutellata ), obvious sublateral grey striped on the scutum (no sublateral stripes in H. scutellata ), 2 obvious dorsocentrale seta (1 dorsocentral seta in H. scutellata ), a densely dusted frons (shining to subshining in H. scutellata ) and obvious long ommatrichia (inconspicious ommatrichia in H. scutellata ). Terminalia as Figs 36-38 .

Distribution. Hyadina scutellata is widely distributed but records are rare and scattered.Surprisingly there are no records from France nor the Iberian Peninsula and the records from Ireland ( Haliday 1839) and Britain ( Drake 2007) mark the western distribution. Eastwards H. scutellata reaches to Talmenka at 83°E (Zatwarnicki 1996). It has so far not been recorded in South Europe and the record from Georgia is the most southern location at 41° N. There are no records from Norway nor Sweden and the most northern findings are from Finland at 65° N (material listed above).

Biology. Hyadina scutellata is a species of freshwater wetlands and has probably a preference for margins of rivers and streams. Adults are recorded from January (Papp 2001) and March to September. This species is polyvoltine and probably overwinters as adult. At least in Germany this species has become rare with the last known record from 1994 (Zatwarnicki & Hollmann-Schirrmacher 1997).

Figures

Figs 5-13. Head, thorax and wing of Hyadina species. 5. Head and thorax of H. pollinosa Oldenberg, dorsal view; 6. head and thorax of H. scutellata (Haliday), dorsal view; 7. head and thorax of H. vernalis (Robineau-Desvoidy), dorsal view; 8. wing of H. guttata (Fallén), dorsal view; 9. wing of H. minima (Papp), dorsal view; 10. wing of H. pollinosa Oldenberg, dorsal view; 11. wing of H. rufipes (Meigen), dorsal view; 12. wing of H. vernalis (Robineau-Desvoidy), dorsal view; 13. wing of H. vockerothi Clausen, dorsal view.

Figs 36-43. Postabdomen of Hyadina scutellata (Haliday) and H. vernalis (Robineau-Desvoidy). 36. Epandrium and cerci of H. scutellata (Haliday), dorsal view; 37. epandrium and cerci of H. scutellata (Haliday), lateral view; 38. tip of postgonite of H. scutellata (Haliday), lateral view; 39. sternites 3 (right) – 5 (left) of H. scutellata (Haliday), ventral view. 40. Epandrium and cerci of H. vernalis (Robineau-Desvoidy), dorsal view; 41. epandrium and cerci of H. vernalis (Robineau-Desvoidy), lateral view; 42. tip of postgonite of H. vernalis (Robineau-Desvoidy), lateral view; 43. sternites 3 (right) – 5 (left) of H. vernalis (Robineau-Desvoidy), ventral view. st3, sternite 3; st4, sternite 4; st5, sternite 5.