Tonnwardsia Jaschhof & Kallweit

Jaschhof, Mathias & Kallweit, Uwe, 2009, The Cycloneura Marshall group of genera in New Zealand (Diptera: Mycetophilidae: Leiini), Zootaxa 2090, pp. 1-39 : 27-28

Genus Tonnwardsia Jaschhof & Kallweit gen. n.

( Figs 6, 7 , 21 , 31 , 38 , 44 )

Type species. Cycloneura aberrans Tonnoir in Tonnoir & Edwards 1927, hereby designated.

Diagnosis. The top of the head is pointed and situated on the same level with the ventral margin of the mesonotum ( Fig. 38 ). The lateral ocelli are close to the eye margins ( Fig. 31 ). The scutum is slightly protruding anteriorly ( Fig. 38 ). The presumed meron is present above the meeting point of preepisternum 2, mid coxa, anepimeron, and laterotergite ( Fig. 38 ). A part of the microtrichia on the wing membrane are more clearly arranged in lines than in most other Leiini. Sc is short and ends free; M is one-branched; CuA2 is sinuous; and A1 is not in touch with CuA2 ( Fig. 21 ). Male sternite 9 bears large, variform processes, which is a synapomorphic character state of Tonnwardsia . The female terminalia are peculiar for the unusually broad basal portions of gonocoxites 8 ( Fig 44 ).

Tonnwardsia is sufficiently different from Cycloneura , its presumed sister group, to warrant distinct generic status. Differences between the two genera include the hind coxa that is very broad in Cycloneura but not so in Tonnwardsia ; the cell cup that is closed in Cycloneura and open in Tonnwardsia ; the male sternite 9 that is not traceable as a separate sclerite in Cycloneura but distinct and equipped with large processes in Tonnwardsia ; and the female gonocoxite 8 that is of ordinary shape in Cycloneura but with very broad basal portion in Tonnwardsia .

Description. Color. Dark brown. Head. Figs 31 , 38 . Head capsule in lateral view higher than long, pointed on top. Foramen situated clearly above midheight of head. Median convexity of postgenae large but weakly sclerotized. Frons asetose. Frontal furrow complete. Frontal tubercle 2-pointed. Antennae inserted below midheight of head. Scape little longer than pedicel, both setose. Fourteen flagellomeres; individual flagellomere cylindrical, with very short stalk; node longer than wide in males and as long as wide in females, covered densely with short trichia; setae largely absent except 2 on apical flagellomeres. Numerous fine interommatidial setulae. Three ocelli in wide triangle, situated frontally, median ocellus smaller than laterals, the latter almost in touch with eye margins. A row of 3 bristles behind upper eye margins plus several bristles behind lateral ocelli and alongside median ocellus, all bristles directed anteriorly. Face subrectangular, weakly sclerotized, with few fine setae. Clypeus ovate, with few fine setae. Labrum very small, weakly sclerotized. Stipes setose. Lacinia not tracable. Maxillary palpus long, 5-segmented, with 2 segments proximally of presumed third; basalmost segment weak and asetose; third segment with sensory pit; apical segment longest, slender. Prementum weak, asetose. Premental apodemes fused mesally, with 2 posterior processes. Labellum setose laterally; tiny prestomal teeth in mesal row.

Thorax. Fig. 38 . Comparatively high, scutum index 2.3, episternum index 0.98. Postpronotum asetose. Suture between antepronotum and proepisternum complete; both sclerites with setae and bristles. Proepimeron situated posteroventrally of proepisternum, long and pointed, fitting into excavation of preepisternum 2. Basisternum 1 asetose. Anepisternum smaller than preepisternum 2, asetose like all other pleura. Anepimeron large; ventral portion narrow, fading away towards thorax margin. Mid-pleural pit well developed, its mound protruding, pleural apodeme funnel-shaped. Laterotergite bulging, rounded ventrally, subrectangular dorsally. Presumed meron present as weakly sclerotized distinct sclerite ventrally between preepisternum 2 and laterotergite. Scutum truncate anteriorly, little protruding, with evenly distributed setae intermingled with bristles. Anterior parapsidal suture not traceable. Median transverse suture weak. Prescutum not traceable. Scutellum setose, with 1–2 lateral bristles. Mediotergite very slightly curved.

Wing. Fig. 21 . Long, wing index 2.6. Membrane with light brown tinge and usually dark markings subapically, on part of anterior margin and near apex of A1; with microtrichia on both sites, those on posterior margin and near apex arranged in lines; setae absent. Calypterous lobe developed, with setose margin. Dmp asetose. Anal lobe slightly angled. C extending little beyond apex of R5, ending well before wing apex. Sc short, ending free. One crossvein (Rs) between R1 and R 5 in proximal half of wing. R1 shorter than ta, ending little beyond mid-wing. R5 straight. M one-branched, weak basally. CuA1 detached basally. CuA2 strongly sinuous. A1 ending free, not in touch with CuA2. CuP very short. A2 absent. Dorsal setae on all veins except h, Sc, Rs, tb, and CuP. Ventral setae on R1 and R5. Halter with light stem and dark knob. Legs. Hind coxa only slightly widened subbasally. Tibial trichia irregularly arranged. Fore tibia shorter than femur, with few anterior setae. Fore tibial organ with semicircular rim, with numerous trichia of which the distalmost form a comb. Mid and hind tibiae with 1 row of large and small bristles, large bristles longer than tibial diameter. Hind tibial apical comb of pale setae present. Tibial spurs 1:2:2, with serrated rims, on mid and hind tibiae unequal in length. Empodia small. Pulvilli not traceable. Claws with 1 large and 1–2 small teeth.

Abdomen. Setose except sternite 1. Male sternites 7 and 8 elongated, as long as sternite 6 and much longer than corresponding tergites. In both sexes weakly pigmeted lateral lines (folds?) on tergites traceable, weaker in females than in males, lacking on sternites.

Male terminalia. Rotated at least 90°. Large, thick, capsule-like. Sternite 9 with posterior pair of large, strongly sclerotized processes of variform outline. Tergite 9 indistinguishably merged with dorsal portions of gonocoxites. Ventral portions of gonocoxites short, separate mesally, with sternite 9 between, with large, strongly sclerotized mesal processes. PostGA rather long and narrow. AntGA short and wide. Gonostylus elongate, inserted ventrolaterally on gonocoxal capsule, clasping vertically. Aedeagus and parameres forming complex elongate, sclerotized structure. Hypoproct larger than cerci, incised apicomesally, with large microtrichia and apical setae. Cerci largely merged, setose apically. Female terminalia. Fig. 44 . Tergite 8 very short dorsally, setose apically. Gonocoxite 8 with very broad basal portion, apically pointed and with numerous large setae. Tergite 9 short, setose. Gonapophyses 9 sclerotized, merged to form large common internal structure. Tergite 10 short, setose. Sternite 10 narrow, setose. Cerci setose, 2-segmented, basicercus little longer than disticercus.

Species included. Our generic description is based on the type species, Tonnwardsia aberrans (Tonn.) , and 6 unnamed species at our disposal. These species will be treated together with those of the genus Cycloneura in a separate paper (Jaschhof & Kallweit, in prep.).

Etymology. We name this genus to honour the merits of the authors of New Zealand Fungus Gnats , André L. Tonn oir (1885–1940) and Frederick W. Ed wards (1888–1940). Gender is feminine.

Figures

FIGURES 5 – 8. Specimens in lateral view. 5: Paracycloneura apicalis Tonnoir, male. 6: Tonnwardsia gen. et sp. n., male. 7: Tonnwardsia gen. et sp. n., female. 8: Cawthronia nigra Tonnoir, male.

FIGURES 19 – 25. Wings. 19: Paracycloneura apicalis Tonnoir, ventral view. 20: Paracycloneura inopinata sp. n., ventral view. 21: Tonnwardsia gen. et sp. n., ventral view. 22: Cawthronia nigra Tonnoir, ventral view. 23: Waipapamyia dentata sp. n., dorsal view. 24: Waipapamyia elongata sp. n., ventral view. 25: Waipapamyia truncata sp. n., ventral view.

FIGURES 30 – 33. Morphology of Leiini. 30: Head, in frontal view, of Cycloneura Marshall sp. 31: Head, in frontal view, of Tonnwardsia gen. et sp. n. 32: Head, in frontal view, of Paracycloneura apicalis Tonnoir. 33: Thorax, in lateral view, of Paradoxa fusca Marshall. Length of scale bar = 0.1 mm (for 30 – 32) and 0.25 mm (for 33).

FIGURES 38 – 39. Thorax, lateral view. 38: Tonnwardsia gen. et sp. n. 39: Paracycloneura apicalis Tonnoir. Length of scale bar = 0.25 mm.

FIGURES 40 – 44. Female terminalia, lateral view. 40: Paradoxa fusca Marshall. 41: Waipapamyia dentata sp. n. 42: Cawthronia nigra Tonnoir. 43: Cycloneura Marshall sp. 44: Tonnwardsia gen. et sp. n. Length of scale bar = 0.05 mm (for 41) and 0.1 mm (for 40, 42 – 44).