22 de octubre de 2020

Variations in the appearance of Diphlebia lestoides

As described by by W. E. Stewart in his 1980 thesis on the genus Diphlebia (https://www.publish.csiro.au/zs/ajzs075), the species D. lestoides has six distinct forms. These are illustrated below from my own sightings.

Diphlebia lestoides lestoides (Selys, 1853)
Southern subspecies, found from the Yarra Valley (Vic) to Gosford (NSW).


Badger weir, Healesville: https://www.inaturalist.org/observations/37514200
Yarra River Walk, Warburton: https://www.inaturalist.org/observations/37514718
Little Peninsula Tunnel, McMahons Creek: https://www.inaturalist.org/observations/37513864
Aberfeldy Bridge, Baw Baw: https://www.inaturalist.org/observations/37511716
Aberfeldy Bridge, Baw Baw: https://www.inaturalist.org/observations/37508190
Woods Reserve, Gibraltar Creek: https://www.inaturalist.org/observations/39694503
Duck Holes Picnic Area, McCarrsCreek: https://www.inaturalist.org/observations/35943254

Males, clear wing

Badger weir, Healesville: https://www.inaturalist.org/observations/37514050
Yarra River Walk, Warburton: https://www.inaturalist.org/observations/37514723
Big Peninsula Tunnel, McMahons Creek: https://www.inaturalist.org/observations/37512926
Aberfeldy Bridge, Baw Baw: https://www.inaturalist.org/observations/37511715
Stringers Creek, Walhalla: https://www.inaturalist.org/observations/37508039
Woods Reserve, Gibraltar Creek: https://www.inaturalist.org/observations/39694385
Duck Holes Picnic Area, McCarrsCreek: https://www.inaturalist.org/observations/35943203

Males, bar wing

Badger weir, Healesville: https://www.inaturalist.org/observations/37514484
Yarra River Walk, Warburton: https://www.inaturalist.org/observations/37514049
Big Peninsula Tunnel, McMahons Creek: https://www.inaturalist.org/observations/37512927
Aberfeldy Bridge, Baw Baw: https://www.inaturalist.org/observations/37511714
Aberfeldy Bridge, Baw Baw: https://www.inaturalist.org/observations/37508126
McKenzie River nature Walk: https://www.inaturalist.org/observations/37507947
Woods Reserve, Gibraltar Creek: https://www.inaturalist.org/observations/39694472

Diphlebia lestoides tillyardi Fraser, 1956
Northern subspecies, found from Barrington Tops (NSW) to Mount Glorious (Qld).


Breakfast Creek, Mount Warning: https://www.inaturalist.org/observations/52249924
Morans Creek, O'Reilly's: https://www.inaturalist.org/observations/35371209
Morans Creek, O'Reilly's: https://www.inaturalist.org/observations/35372305

Males, clear wing

Morans Creek, O'Reilly's: https://www.inaturalist.org/observations/55410635
Morans Creek, O'Reilly's: https://www.inaturalist.org/observations/35370990

Males, bar tip wing

Breakfast Creek, Mount Warning: https://www.inaturalist.org/observations/52249919
Morans Creek, O'Reilly's: https://www.inaturalist.org/observations/55410728
Morans Creek, O'Reilly's: https://www.inaturalist.org/observations/35371340
Morans Creek, O'Reilly's: https://www.inaturalist.org/observations/35372441
Morans Creek, O'Reilly's: https://www.inaturalist.org/observations/35400294

Ingresado el 22 de octubre de 2020 por jeff_melvaine jeff_melvaine | 0 comentarios | Deja un comentario

09 de diciembre de 2019

Identification of the three most similar species of Diphlebia (Rockmaster damselflies, Eastern Australia)

In posting my own sightings on this site, I found that I was struggling to differentiate the females of the sometimes sympatric species D. coerulescens and D. nymphoides from photographs taken from whatever angle the subjects permitted. More recently, differentiation of male and female D. euphoeoides from D. coerulescens has been an issue of interest on this site; I have often relied on their disjoint known ranges to resolve these questions, but it is appropriate to approach any suggestions of sightings outside those ranges in the spirit of objective scientific enquiry. The information in the Theischinger and Hawking field guide (2006) and the Theischinger and Endersby identification guide (2009) appears quite adequate for identification with a captive or preserved specimen in hand, but often left me in considerable doubt when working from a single opportunistic snapshot. Rather than assuming that females would be conspecific with the nearest Diphlebia males (if any), I decided that I would obtain a copy of W. E. Stewart's definitive 1980 paper on the genus, cited as the basis for the treatment of Diphlebia since the Watson, Theischinger and Abbey guide (1991). The figures that I found most useful for photographic IDs depicted the dorsal and lateral abdominal views, but Stewart's paper was formatted to present this information as compactly as possible, and I found it necessary to construct a composite image that permitted direct comparison on the same page of the patterns for each species. I am now endeavouring to share that image with others here.


Ingresado el 09 de diciembre de 2019 por jeff_melvaine jeff_melvaine | 1 comentario | Deja un comentario