Cawthronia Tonnoir & Edwards 1927

Jaschhof, Mathias & Kallweit, Uwe, 2009, The Cycloneura Marshall group of genera in New Zealand (Diptera: Mycetophilidae: Leiini), Zootaxa 2090, pp. 1-39 : 28-29

Genus Cawthronia Tonnoir & Edwards 1927

Tonnoir & Edwards 1927: 825 (description).

Type species. Cawthronia nigra Tonnoir in Tonnoir & Edwards 1927, by monotypy.

Diagnosis. The top of the head is rounded rather than pointed and situated slightly above the level of the ventral margin of the mesonotum ( Figs 8 , 36 ). The lateral ocelli are far from the eye margins ( Fig. 28 ). The thorax is flat, mainly due to preepisternum 2 that is truncate ventrally ( Fig. 36 ). The scutum is rounded anteriorly, not protruding ( Fig. 36 ). Sc is long and joins C; the M-fork is evenly diverging towards the wing apex; and A1 is curved posteriorly ( Fig. 22 ). The dorsal wall of the male gonocoxites is desclerotized ( Fig. 85 ), which is an autapomorphic character state.

Redescription. Color. Dark brown. Head. Head capsule in lateral view little higher than long, rounded on top. Foramen situated little above midheight of head. Median convexity of postgenae sclerotized. Frons setose. Frontal furrow complete. Frontal tubercle 2-pointed. Antennae inserted below midheight of head. Scape little longer than pedicel, both setose. Fourteen flagellomeres; individual flagellomere slightly compressed, with very short stalk; node little shorter to longer than wide in males, much shorter than wide in females, covered densely with short trichia of which the bases form polygon-like patterns; setae absent in males, 2 setae present on apical flagellomeres of females. Numerous fine interommatidial setulae. Three ocelli in wide triangle on top of head, median ocellus little smaller than laterals, the latter far from eye margins. Postcranium and frons densely covered with setae of various sizes including 4–5 large setae behind ocelli. Face subrectangular, setose. Clypeus rounded, smaller than face, setose. Labrum very small, weakly sclerotized, asetose. Stipes strongly setose. Lacinia not traceable. Maxillary palpus long, 4-segmented, with 1 segment proximally of presumed third; basalmost segment weak, asetose, lacking wartlike sensilla; third segment with sensory pit; apical segment long, slender. Prementum weak, asetose. Premental apodemes fused mesally, with 2 posterior processes. Labellum with lateral setae and prestomal teeth in long, dense mesal row.

Thorax. Flat, scutum index 2.49, episternum index 0.68. Postpronotum asetose. Suture between antepronotum and proepisternum complete; both sclerites with setae and anteriorly directed bristles. Proepimeron situated posteroventrally of proepisternum, long and pointed, fitting into notch of preepisternum 2. Basisternum 1 asetose. Anepisternum and preepisternum 2 subequal in size, with distinct suture between, both sclerites asetose like all other pleura. Preepisternum 2 covering basalmost portion of mid coxa. Anepimeron large; ventral portion narrow, occupying a space between preepisternum 2 and laterotergite. Mound of mid-pleural pit flat, pleural apodeme funnel-shaped. Laterotergite ovate, bulging, darker than pleura. Scutum rounded, not protruding anteriorly, with evenly distributed setae intermingled with bristles on lateral margin. Anterior parapsidal suture indistinct. Prescutum not traceable. Scutellum with setae and 2 lateral bristles. Mediotergite slightly arched. Wing. Long, wing index 2.2. Membrane with brown tinge, a portion above media darkened; with microtrichia on both sites and some setae close to posterior margin and on apex. Calypterous lobe developed, with setose margin. Dmp asetose. Anal lobe angled. C extending much beyond apex of R5, ending clearly before wing apex. Sc long, joining C. One crossvein (Rs) between R1 and R 5 in proximal half of wing. R1 longer than ta, ending in distal half of wing. Apical portion of R5 approaching C. M furcate; M-stem shorter than fork; tines of M-fork evenly diverging towards wing apex. CuA1 long, basally evanescent. CuA2 sinuous. CuP present as short fold. A1 not reaching wing margin, curved strongly posteriorly. A2 absent. Dorsal setae on all veins except h, Sc, Rs, tb, and CuP. Ventral setae on R1 and R5. Legs. Hind margin of hind coxa slightly protruding. Tibial and tarsal trichia irregularly arranged. Fore tibia shorter than femur, with very short setae. Fore tibial organ with semicircular rim, with numerous pale trichia of which the distalmost form a comb. Mid and hind tibiae with 2–3 rows of setae, longest setae longer than tibial diameter. Hind tibial apical comb of pale setae absent. Tibial spurs 1:2:2, with serrated rims, on mid and hind tibiae unequal in length. Empodia as long as pretarsal claws. Pulvilli not traceable. Claws with 1 large and 2 small teeth.

Abdomen. Setose except sternite 1. Male segments 7 and 8 very short and telescoped. Light, weakly pigmentd lateral lines (folds?) on tergites and sternites 2–6 in both sexes.

Male terminalia. Large, not rotated. Sternite 9 absent as separate sclerite. Tergite 9 short, separate from gonocoxites. Gonocoxites elongate, broadly merged ventrobasally, with V-shaped ventral emargination; dorsal portions desclerotized and asetose. PostGA reduced. AntGA moderately long. Gonostylus small, simple. Aedeagus/paramere complex with large membranous and very small sclerotized portions; ejaculatory apodeme long, weakly sclerotized. Hypoproct setose. Cerci largely merged, setose. Female terminalia. Tergite 8 moderately long, setose. Gonocoxite 8 pointed apically, with some large apical setae. Tergite 9 very short, setose. Gonapophyses 9 sclerotized, merged to form internal common structure. Tergite and sternite 10 merged, setose. Cerci setose, 2-segmented.

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 34 – 37. Thorax, lateral view. 34: Sigmoleia similis sp. n. 35: Waipapamyia dentata sp. n. 36: Cawthronia nigra Tonnoir. 37: Cycloneura Marshall sp. Length of scale bar = 0.5 mm.

FIGURES 26 – 29. Head in frontal view. 26: Paradoxa fusca Marshall. 27: Sigmoleia peterjohnsi sp. n. 28: Cawthronia nigra Tonnoir. 29: Waipapamyia dentata sp. n. Length of scale bar = 0.1 mm.

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 80 – 89. Cawthronia nigra Tonnoir. 80: Gonostylus, ventral view (0.05 mm). 81: Gonostylus, mesal view (0.05 mm). 82: Gonostylus, dorsal view (0.05 mm). 83: Male terminalia, ventral view (0.1 mm). 84: Aedeagus / tegmen complex, ventral view (0.1 mm). 85: Male gonocoxites and cerci, dorsal view (0.1 mm). 86: Male flagellomeres 1 – 5, lateral view (0.1 mm). 87: Female flagellomeres 1 – 5, lateral view (0.1 mm). 88: Male tergite 9, dorsal view (0.1 mm). 89: Male flagellomere 4, lateral view (0.05 mm). Length of scale bar in parentheses.