Dicerura jakovlevi Jaschhof & Spungis, 2018

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 : 88-89

Dicerura jakovlevi Jaschhof & Spungis sp. nov.

Figs 1–2

Diagnosis. Dicerura jakovlevi differs from the other species of the iridis group in the gonostylus, whose small mediobasal lobe is angular-shaped and markedly bulging ( Fig. 1 , ↓1); the gonocoxites, whose ventroposterior edge is broadly, darkly pigmented ( Fig. 1 , ↓2); and the tegmen, whose basal portion is unusually strongly constricted, thus providing just a narrow base for the broader, cap-like apex ( Fig. 1 , ↓3). See below D. stipator ( Figs 25–27 ),

which is another member of the iridis group with darkly pigmented gonocoxites.

Other male characters. Body length 3.0 mm. Head. Eye bridge 3–4 ommatidia long dorsally. Antenna as long as body; scape and pedicel concolorous with flagellum. Circumfila with 1–2 rather short extensions. Neck of fourth flagellomere 1.6 times longer than node. Palpus 4-segmented, 0.8 times the length of head height, third and fourth segments with tendency to merge. Thorax. Scutum with dark stripes dorsally and laterally. Anepisternum with 2–3 setae. Wing as long as body, with brownish tinge. M1+2 weak, reduced to short remnants apically and basally. Legs. Empodia rudimentary. Claws slightly bent, 3–4 basal teeth gradually decreasing in size. Genitalia. Ninth tergite subtrapezoid, strongly tapered towards apex, with setae of various lengths dispersed over entire surface; anterior edge straight, faintly contoured; posterior edge either truncate (holotype) or slightly concave (paratype), densely covered with short, thick microtrichia ( Fig. 2 ). Gonocoxites: ventral emargination angular, with slightly convex basal edge; ventromedial processes slightly smaller than dorsolateral processes, all with dense, large microtrichia and a few setulae; dorsal portions strongly protruding posteriorly; dorsal apodemes moderately long ( Fig. 1 ). Gonostylus 1.5 times longer than broad, strongly tapered towards apex ( Fig. 1 ). Apex of tegmen broadly rounded, 1 small, sclerotized barb on either side ( Fig. 1 ). Apical fork of ejaculatory apodeme rather small, one fourth as long as apodeme’s total length ( Fig. 1 ).

Etymology. We name this new species after the Russian entomologist Jevgeni Jakovlev (Vantaa, Finland), in appreciation of his valuable contributions to the taxonomy, faunistics and biology of northern European Sciaroidea.

Type material. Holotype. Male , Finland, Tavastia australis, Lammi, Biological Station, emergence trap on trunk of gray alder, 28 July–27 September 2005, J. Jakovlev (in MZH). Paratype . Male, same data as for the holotype (specimen no. A 7775 in SDEI).

Figures

FIGURES 1–2. Dicerura jakovlevi, male, holotype. 1: Genitalia, ventral. 2: Ninth tergite, dorsal. Scales 0.05 mm. Arrows refer to characters described in the diagnosis.

FIGURES 25–27. Dicerura Stipator, male, syntype. 25: Genitalia (gonostyli omitted), ventral. 26: Ninth tergite, dorsal. 27: Tegmen and ejaculatory apodeme, ventral. Scales 0.05 mm. Arrows refer to characters described in the diagnosis.