Tetraneuromyia lamellata Spungis, 1987

Jaschhof, Mathias & Jaschhof, Catrin, 2019, New Dicerurini from Europe, mostly Sweden (Diptera: Cecidomyiidae, Porricondylinae), Zootaxa 4559 (2), pp. 245-264 : 256-257

Tetraneuromyia lamellata Spungis, 1987

Figs 25–27, 29

Most records published of T. lamellata refer to male adults; larvae of this species remain unknown. Spungis’s (1987) original description drew upon eight males (including the holotype) and one female (designated the paratype) from Latvia and north European Russia, whereas Mamaev (1990) described the same species under the name of Pterepidosis apicalis from a single male collected in central European Russia (see Jaschhof & Jaschhof 2013: 158). The male description we presented earlier was based on eight specimens found in Sweden ( Jaschhof & Jaschhof 2013: 158), a publication later used for identifying four males from the Czech Republic as being conspecific ( Sikora et al. 2017). Doubts on the identity of T. lamellata arose when we observed that in six males collected in 2016 in Swedish Lapland the gonocoxal emargination was, invariably, strongly and extensively sclerotized ( Fig. 25 , ↓ 1). This peculiarity, which we had previously noticed in only one of our specimens and thus regarded as intraspecific variation ( Jaschhof & Jaschhof 2013: 158), prompted us to re-examine side by side both our previous and recently obtained specimens, altogether 14 adequately prepared males. As a result we arrived at the conclusion that T. lamellata sensu Jaschhof and Jaschhof (2013) includes two discrete species. Voldemars Spungis informed us (by letter of 14 August 2018) that the same peculiarity distinguishing our specimens from Lapland is found also in the holotype of T. lamellata , the consequence being that figure 75 in Jaschhof & Jaschhof (2013) refers to a different species, described in the present paper as T. errata . The fact that this sibling went unrecognized for quite some time indicates how closely it resembles T. lamellata . Characters to distinguish the two species are explained under T. errata . Interestingly, both species may co-occur at the same sites, such as Tyresta (Södermanland, Sweden). Two females in our material, one associated with a male T. lamellata , the other with a male T. errata , proved to be indistinguishable from each other. Specimens published earlier as T. lamellata and not validated here should be reviewed, particularly the Czech records of this species (see above). The identity of Pterepidosis apicalis Mamaev, 1990 with T. lamellata established in Jaschhof & Jaschhof (2013: 158) is confirmed here, based on our re-examination of the holotype of P. apicalis .

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Material studied. Sweden: 4 males, Pite Lappmark, Arjeplog, Jäkkvik, herb-rich subalpine birch forest, 16 August 2016, aspirator, MCJ (spms nos CEC1569 – CEC 1572 in SDEI) ; 1 male, Lule Lappmark, Sorsele, 6 km N Ammarnäs, Bissitjbäcken , mire in pine/birch forest, 23 July–15 Aug. 2016, MT, MCJ (spm. no. CEC 1573 in NHRS) ; 1 male, Lule Lappmark, Jokkmokk, Luottåive NR, swampy spruce/birch forest, 30 July–30 August 2016, MT, MCJ (spm. no. CEC 1574 in NHRS) ; 1 male, 1 female, Södermanland, Tyresta NP, over aspen log, 28 July–20 September 2000, MT , B. Viklund, L.- O. Wikars & H. Ahnlund (spms nos. NHRS-GULI000021934 – NHRS- GULI000021935 ) . Russia: holotype male of Pterepidosis apicalis Mamaev, 1990 , with collecting data as specified in the original description (spm. no. P-Di 154 in ZMUM) .

Figures

FIGURES 25–31. Tetraneuromyia lamellata, males, from Sweden. 25: Genitalia, ventral. 26: Tegmen, ventral. 27: Tegmen, ventral. 29: Gonostylus, ventral. Tetraneuromyia errata, males. 28: Tegmen, ventral, holotype. 30: Gonostylus, ventral, specimen from Skåne. 31: Genitalia, ventral, holotype. Scales for 25–27, 29–31, 0.05 mm, for 28, 0.025 mm. Arrows refer to characters described in the diagnosis.