Dicerura

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 : 101-102

Key to male Dicerura in the Palearctic region

1 Anepisternum setose.................................................................................. 2

- Anepisternum asetose................................................................................ 14

2 Apical fork of ejaculatory apodeme with parallel, closely adpressed tines ( Fig. 8 ). Gonostylus without mediobasal lobe ( Fig. 6 )................................................................................................... 3

- Apical fork of ejaculatory apodeme with tines diverging, at least at the very end ( Fig. 1 ). Gonostylus with medial or mediobasal, mostly bulging lobe marked by dense microtrichia ( Figs 1 , 20 )...................................... 5

3 Gonostylus conspicuously broad and curved apically. Ventral gonocoxal emargination with asetose, broadly rounded lobe basally................................................................................... D. complicata

- Gonostylus narrow apically, evenly rounded to pointed ( Fig. 6 ). Ventral gonocoxal emargination bordered by 2 pairs of processes ( Fig. 6 )....................................................................................... 4

4 Gonostylus broadly rounded apically ( Fig. 6 ). Ninth tergite with small, pointed lobes posterolaterally ( Fig. 7 ).. D. yezoensis

- Gonostylus narrowly rounded apically ( Fig. 16 ). Ninth tergite with V-shaped incision posteromedially ( Fig. 17 ). D. formosa

5 Apical fork of ejaculatory apodeme with tines conjoined medially by membrane leaving just the tips separate ( Fig. 19 )................................................................................................. D. furculata

- Tines of apical fork of ejaculatory apodeme not conjoined by membrane ( Fig. 5 ).................................. 6

6 Gonocoxites conspicuously densely setose ventrally, ventral emargination bordered by a single pair of processes......... 7

- Gonocoxites with ventral setae sparse or normally dense, ventral emargination bordered by 2 pairs of processes ( Fig. 1 )... 8

7 Apical fork of ejaculatory apodeme provided with tiny spines and merged with tegmen.................... D. peterssoni

- Apical fork of ejaculatory apodeme smooth and separate from tegmen.................................. D. fungicola

8 Ventroposterior margin of gonocoxites broadly, darkly pigmented.............................................. 9

- Ventroposterior margin of gonocoxites not darkly pigmented................................................. 10

9 Apical fork of ejaculatory apodeme serrate on medial edges ( Fig. 27 ). Tegmen pointed apically ( Fig. 27 )........ D. stipator

- Apical fork of ejaculatory apodeme not serrate ( Fig. 1 ). Tegmen broadly rounded apically ( Fig. 1 )............ D. jakovlevi

10 Tines of apical fork of ejaculatory apodeme with frayed ends ( Fig. 24 ). Medial lobe of gonostylus longer than half the gonostylar length ( Fig. 22 )............................................................................... D. iridis

- Tines of apical fork of ejaculatory apodeme not frayed. Mediobasal lobe of gonostylus clearly shorter than half the gonostylar length............................................................................................. 11

11 Apical fork of ejaculatory apodeme about one third the apodeme’s total length, tines conspicuously slender............ 12

- Apical fork of ejaculatory apodeme about one fourth of apodeme’s total length, tines not particularly slender ( Fig. 3 ).... 13

12 Gonostylus as long as gonocoxite, apex bent inwards, conspicuously densely setose. Tegmen strongly constricted subapically, rounded posteriorly............................................................................ D. rossica

- Gonostylus longer than gonocoxite, apex not bent, normally setose. Tegmen moderately constricted subapically, pointed posteriorly..................................................................................... D. xylophila

13 Ventral emargination of gonocoxites angular-shaped ( Fig. 3 ). Mediobasal lobe of gonostylus roundish ( Fig. 3 ).. D. penttineni

- Ventral emargination of gonocoxites evenly rounded. Mediobasal lobe of gonocoxites angular-shaped...... D. triangularis

14 Empodia as long as tarsal claws........................................................................ 15

- Empodia vestigial................................................................................... 16

15 Gonocoxites with darkly pigmented area around ventral emargination ( Fig. 28 ). Tegmen with 4–6 sclerotized barbs of various sizes apicolaterally ( Fig. 31 )................................................................... D. unidentata

- Gonocoxites without darkly pigmented area. Tegmen with 6 or more sclerotized barbs of about same size apicolaterally................................................................................................. D. dentata

16 Apex of tegmen strongly narrowed. Gonocoxal processes absent.............................................. 17

- Apex of tegmen broadly rounded, truncate or concave. Gonocoxal processes present or absent....................... 18

17 Gonocoxal emargination with convex basal edge ( Fig. 13 ). Tegminal apex acutely pointed ( Fig. 15 )........... D. foliicola

- Gonocoxal emargination with concave basal edge. Tegminal apex narrowly rounded......................... D. mixta

18 Eye bridge 0–1 ommatidium long....................................................................... 19

- Eye bridge 3-4 ommatidia long......................................................................... 20

19 Ventral emargination of gonocoxites with small, setose protuberances basolaterally........................ D. dispersa

- Ventral emargination of gonocoxites bordered by 2 pairs of processes.................................... D. feminea

20 Gonostylus with medio-subapical lobe ( Fig. 10 ). Ventral gonocoxal emargination extremely large, with microtrichose lobe basally ( Fig. 11 )............................................................................... D. barbata

- Gonostylus with mediobasal lobe. Ventral gonocoxal emargination small, without lobe.................... D. separata

Figures

FIGURES 6–8. Dicerura yezoenSiS, male, holotype. 6: Genitalia, ventral. 7: Ninth tergite, dorsal. 8: Tegmen (apex slightly distorted) and ejaculatory apodeme, ventral. Scales 0.05 mm. Arrows refer to characters described in the diagnosis.

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 19–21. Dicerura furculata, male, from Finland. 19: Genitalia, ventral. 20: Gonostylus, ventral. 21: Tegmen and ejaculatory apodeme, ventral. Scales 0.05 mm. Arrows refer to characters described in the diagnosis.

FIGURES 16–18. Dicerura formoSa, male, from Sweden. 16: Genitalia, ventral. 17: Ninth tergite, dorsal. 18: Tegmen and ejaculatory apodeme, ventral. Scales 0.05 mm. Arrows refer to characters described in the diagnosis.

FIGURES 3–5. Dicerura penttineni, male, holotype. 3: Genitalia, ventral. 4: Ninth tergite, dorsal. 5: Tegmen and ejaculatory apodeme, ventral. 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.

FIGURES 22–24. Dicerura iridiS, male, from Latvia. 22: Genitalia, ventral. 23: Ninth tergite, dorsal. 24: Tegmen and ejaculatory apodeme, ventral. Scales 0.05 mm. Arrows refer to characters described in the diagnosis.

FIGURES 28–31. Dicerura unidentata, male, from Estonia. 28: Genitalia, ventral. 29: Ninth tergite, dorsal. 30: Gonostylus, ventral. 31: Tegmen and ejaculatory apodeme, ventral. Scales 0.05 mm. Arrows refer to characters described in the diagnosis.

FIGURES 13–15. Dicerura foliicola, male, holotype. 13: Genitalia, ventral. 14: Ninth tergite, dorsal. 15: Tegmen and ejaculatory apodeme, ventral. Scales 0.05 mm. Arrows refer to characters described in the diagnosis.

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.