Chironomid Exchange Forum

Methods and other themes => Identification => Topic started by: bruno.rossaro@unimi.it on December 06, 2023, 02:10:36 PM

Title: Paratanytarsus species
Post by: bruno.rossaro@unimi.it on December 06, 2023, 02:10:36 PM
The species has a characteristic anal point a short median volsella and a superior volsella with a large digitus, can somebody help me in identification ?paratanyt_nsp_Molgora_17X09_SV_x100.jpg
Title: Re: Paratanytarsus species
Post by: Martin Spies on December 06, 2023, 02:53:33 PM
Dear Bruno,

In order to narrow down the range of references that may have to be consulted: Do I gather correctly that the source for your material is the Torrente Molgora, a (?fast-)running water East of Milano?

Best,

Martin Spies
Title: Re: Paratanytarsus species
Post by: Bruno Rossaro on December 06, 2023, 04:25:41 PM
Yes Molgora is a stream running at East of Milano;
I suspected some similarity with P. corsicanus (publ. in Fauna Norvegica) but anal point in dorsal aspect seems different, and I have not the lateral aspect; digitus seems also different, only median volsella is similar
Title: Re: Tanytarsus species
Post by: Bruno Rossaro on December 06, 2023, 06:54:40 PM
An important addition; I overlooked tibial combs, they are clearly separated, this character suggests Tanytarsus not Paratanytarsus as genus; I thanks Wojciech Gilka for the having put me on the advice
Title: Re: Paratanytarsus species
Post by: Wojciech Giłka on December 06, 2023, 06:59:31 PM
Looks similar to Tanytarsus reei Na et Bae, 2010 (Tanytarsus heusdensis group)
Title: Re: Paratanytarsus species
Post by: Wojciech Giłka on December 06, 2023, 07:11:40 PM
Not exactly as Bruno wrote. The structure of tibial cobms and spurs is rather weak character for separation the two genera - combs can be slightly separated and armed with a short spur in both Tanytarsus and Paratanytarsus.
Besides, I was able to see hypopygium only. The presence of spinulae (absent in Paratanytarsus) is the best key character in this case. The species fits the concept of the heusdensis group and should be compared with T. reei.
Title: Re: Paratanytarsus species
Post by: Bruno Rossaro on December 07, 2023, 09:19:55 AM
Yes surely; unfortunately the wings are not in good condition so it is not clear if Cu brings setae; median volsella lamellae are also difficult to analyze, but I cannot exclude that they are branched; body colour is very light suggesting T. heusdensis, because T. reei is described with darker vittae, only the enlarged digitus suggests T. reei; Molgora is a stream in lowland, the habitat is also compatible with T. heusdensis.
My conclusion is that the species is T.heusdensis, the presence of T.reei in Italy at present is not supported.