Dicerura barbata Mamaev, 1966

Jaschhof, Mathias & Spungis, Voldemars, 2018, Towards reliable identification of male Dicerura: descriptions of three new and seven poorly known species in the Palearctic region (Diptera: Cecidomyiidae, Porricondylinae), Zootaxa 4422 (1), pp. 85-103 : 91-92

Dicerura barbata Mamaev, 1966

Figs 9–12

Dicerura barbata was previously known only from the original material, referred to by Mamaev (1966) as consisting of four males (including the holotype) and a female, from two separate localities in Ukraine . The morphological description in the same publication takes no account of the female; rather it is stated there that females of this species were unknown. We identified a male from northern Sweden as conspecific with D. barbata based on the genitalic drawing provided with the original description ( Mamaev 1966: fig. 6.3).

Diagnosis. The gonocoxites of D. barbata are quite unlike that of all other Dicerura in having an extremely

large emargination ventrally, which leaves just a short, asetose intercoxal bridge; the emargination is partly filled with an ovate, microtrichose lobe ( Fig. 11 , ↓1). The large, subtriangular gonocoxal processes are densely microtrichose medially; the dorsal apodemes are conspicuously long and thin ( Fig. 11 , ↓2). The elongate gonostylus

has a small side lobe subapicomedially, which is covered apically and dorsally with dense, large microtrichia, a few setulae, and 1–2 short bristles ( Fig. 10 , ↓3). The apical fork of the ejaculatory apodeme is perfectly V-shaped ( Fig.

12). The elongate, parallel-sided tegmen, which is membranous for the most part, has a broadly rounded apex and a single pair of small, sclerotized processes subapicolaterally ( Fig. 12 , ↓4). The apex of the ninth tergite is bilobed

and densely covered with short, thick microtrichia, especially along the edge and on the inside ( Fig. 9 ).

Remarks. The only specimen of D. barbata examined here is remarkable for the presence of a distinct,

complete M1+2, a vein usually regarded as vestigial in Dicerura . Mamaev (1966) did not mention this vein in his

description of D. barbata .

Material examined. Sweden: male, Lule Lappmark, Jokkmokk, Kaltisbäcken NR, herb-rich old-growth taiga

near stream, 10 July 2016, aspirator, M. Jaschhof (specimen no. CEC 1385 in NHRS).

Figures

FIGURES 9–12. Dicerura barbata, male, from Sweden. 9: Ninth tergite, dorsal. 10: Gonostylus, ventral. 11: Genitalia, ventral. 12: Tegmen and ejaculatory apodeme, ventral. Scales 0.05 mm. Arrows refer to characters described in the diagnosis.