Hyadina vernalis (Robineau-Desvoidy, 1830)

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 : 60

Hyadina vernalis (Robineau-Desvoidy, 1830)

Hydrina vernalis Robineau-Desvoidy 1830: 795 ; type-locality:locus typicus not given [presumably France]; no information available about type material [missing from coll. Robineau-Desvoidy, Mathis & Zatwarnicki 1995].

Hyadina humeralis auct. nec. Becker, 1896.

Unpublished material: CROATIA: 2♀♀, 25.vi.2017, Ðuračica 5 km s Magić Mala [45.133°N 17.596°E], leg. et coll. Stuke ; 1♀, 24.vi.2017, fishponds 1.5 km ne Stražanac [45.635°N 17.097° E], leg. et coll. Stuke ; 1♀, 24.vi.2017, fishponds Ripnjaci [45.521° N 16.936°E], leg. Stuke ; 1♀, 27.vi.2017, floodplain Danube 1 km se Tikveš [45.668°N 18.853°E], leg. et coll. Stuke ; 13, 28.vi.2017, floodplain Drava n Kopačevo [45.608°N 18.789° E], leg. et coll. Stuke ; 1♀, 23.vi.2017, floodplain Sava s Suvoj [45.372° N 16.687°E], leg. et coll. Stuke ; FINLAND: 1♀, 9.viii.2022, Jätärin s Kuusamo [65.956°N 29.168° E], leg. et coll. Stuke ; GEORGIA: 1♀, 8.vii.2019, Kura River n Akhalsheni [42.005° N 43.723° E], leg. et coll. Stuke ; 13 1♀, 3.vii.2019, Snostskali River 0.6 km se Achkhoti [42.618° N 44.624° E], leg. et coll. Stuke.

Diagnosis. Hyadina vernalis belongs to the group that is characterised by (i) only inner vertical seta developed and (ii) scutellum velvet black laterally ( Fig. 7 ). It is the only species of this group without white patches before and behind dm-cu. However, these white patches can easily be overlooked in other species and therefore other characters should be considered, especially that tergite 5 is all over covered with microtrichia and additionally longer setulae ( Fig. 15 ). Terminalia as Figs 40-42 .

Distribution. Hyadina vernalis is a quite common species and widely distributed in Europe. It is recently recorded from Portugal (Stuke et al. 2023 as H. humeralis auct.), occurs in Calabria, Italy (Canzoneri & Vienna 2000 as H. humeralis auct.) and Georgia (material listed above). In Finland it has been found up to 66° N (material listed above). Lack of records in larger areas like Spain, parts of the Balkan or western Scandinavia are very probably due to the absence of collecting activities. The only record of H. vernalis outside of Europe is from the Kuril Islands (“Kunaschir, Sernawodsk”, Dahl 1968 as H. humeralis auct.) and should be checked carefully.

Biology. Hyadina vernalis inhabits different kinds of wetlands including wet meadows, salty places, margins of rivers, ditches, streams or lakes. Adults of H. vernalis were found all year round, the species is very probably polyvoltine and might overwinter as adult. The Laboulbeniales Stigmatomyces spiralis Thaxter, 1901 is reported at H. vernalis (Rossi 1993 as H. humeralis auct.).

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 14-19. Abdomen of Hyadina species. 14. Tergite 5 of H. guttata (Fallén), dorsal view; 15. tergite 5 of H. vernalis (Robineau-Desvoidy), dorsal view; 16. epandrium and cerci of H. fenestrata Becker, dorsal view; 17. epandrium and cerci of H. fenestrata Becker, lateral view; 18. tip of postgonite of H. fenestrata Becker, lateral view; 19. sternites 3 (right) – 5 (left) of H. fenestrata Becker, ventral view. ce, cercus; ep, epandrium; st3, sternite 3; st4, sternite 4; st5, sternite 5; su, surstylus.

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.