Sigmoleia 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 : 7-9

Genus Sigmoleia Tonnoir & Edwards 1927

Tonnoir & Edwards 1927: 826 (description); Matile 1993: 172 (discussion, New Caledonian species). Type species. Sigmoleia melanoxantha Edwards in Tonnoir & Edwards 1927, by original designation.

Diagnosis. Species of Sigmoleia have the following synapomorphies: the premental apodeme has 1 posterior process; the maxillary palpi are shortened ( Fig. 27 ); the mesepisternum is setose ( Fig. 34 ); the fore and mid tibiae are asetose; and the female hypoproct is enlarged. The male terminalia are rather uniform, with genusspecific character states as follows. The gonocoxites have a large ventral emargination and narrow lateral processes (Fig. 55); the gonostyli bear abundant short macrosetae (Fig. 55); the ejaculatory apodeme is absent (Fig. 58); and the parameres are fused to form a tegmen (Fig. 58). The top of the head is pointed and situated on the same level with the ventral margin of the mesonotum ( Fig. 34 ). The lateral ocelli are far from the eye margins ( Fig. 27 ). The scutum is strongly arched ( Fig. 34 ). Preepisternum 2 and laterotergite are in touch ventrally ( Fig. 34 ). Sc is short and ends free; the M-fork is shortened; ta is very short; CuA is furcate; CuA1 joins CuA2 to form a closed cua1; and A1 joins CuA2 to form a closed cup ( Fig. 14 ).

Redescription. Color. Dark brown, abdominal tergites with light anterior margins. Head. Head capsule in lateral view higher than long, pointed on top, evenly setose. Foramen situated clearly above midheight of head. Median convexity of postgenae not or weakly sclerotized. Frons setose. Frontal furrow complete. Frontal tubercle 1-pointed. Antennae inserted below midheight of head. Scape little longer than pedicel, both setose. Fourteen flagellomeres; individual flagellomere cylindrical, with very short stalk; node in both sexes little shorter to little longer than wide, with short trichia, setae absent. Numerous fine interommatidial setulae. Three ocelli almost in line, situated frontally, median ocellus smaller than laterals, the latter far from eye margins. Face subrectangular, setose, with rows of setae along mesal eye margins. Clypeus rounded, smaller than face, setose. Labrum small, asetose. Stipes strongly setose. Lacinia absent. Maxillary palpus short, 3- segmented, with one segment proximally of presumed third; basalmost segment very small and asetose; third segment thick, with dorsomesal sensory pit; apical segment elongate. Prementum weak, asetose. Premental apodemes fused mesally, with 1 large posterior process. Labellum setose laterally; large prestomal teeth in long mesal row.

Thorax. High, scutum index 2.0, episternum index 1.0. Postpronotum asetose. Suture between antepronotum and proepisternum incomplete, both sclerites with setae of various sizes. Proepimeron situated posteroventrally of proepisternum, truncate, fitting into shallow excavation of anepisternum. Basisternum 1 asetose. Anepisternum slightly larger than preepisternum 2, with distinct suture between, with numerous short setae. Preepisternum 2 covering basalmost portion of mid coxa, with few fine dorsal setae. Anepimeron small, approaching laterotergite ventroposteriorly. Anterior basalare setose. Mid-pleural pit slit-like, its mound with membranous area. Laterotergite ovate, bulging, strongly setose, anteriorly in touch with preepisternum 2. Scutum slightly pointed and protruding anteriorly, markedly arched, with evenly distributed setae intermingled with lateral bristles. Prescutum not traceable. Scutellum setose. Mediotergite very slightly curved. Wing. Long, wing index 2.3. Membrane with light brown tinge; dark markings apically, along proximo-anterior margin, around ta and bend of CuA2; with microtrichia on both sites and some setae close to posterior margin. Calypterous lobe well developed, with setose margin. Dmp asetose. Anal lobe slightly angled. C extending much beyond apex of R5 and almost to wing apex. Sc short, ending free. One crossvein (Rs) present between R1 and R 5 in proximal half of wing. Length of Rs variable, sometimes extremely short which results in R1 and R5 being almost in touch. R1 much longer than ta, ending in distal half of wing. R5 straight. M furcate, M-stem slightly shorter to longer than fork, tines of M-fork evenly diverging towards wing apex, or M1 strongly sinuous. CuA furcate. CuA2 angled twice; CuA1 joining CuA2 at anterior bend to form cua1, A1 joining CuA2 at posterior bend to form a closed cup. CuP foldlike, very short. A2 absent. Dorsal setae present on all veins except h, Sc, Rs, and CuP. Ventral setae present on R1, R5, and in some species also on ta and tb. Halter with light stem and dark knob. Legs. Hind coxa not widened subbasally. Tibial and most tarsal trichia irregularly arranged. Fore tibia shorter than femur. Fore tibial organ with semicircular rim, with numerous pale trichia of which the distalmost form a comb. Fore and mid tibiae asetose, hind tibia with row of setae, longest setae as long as tibial diameter. Mid tarsi with sole of 2 rows of short setae, hind tarsi with up to 4 rows of setae. Hind tibial apical comb of pale setae lacking. Tibial spurs 1:2:2, with serrated rims; spurs on mid and hind tibiae unequal in length. Empodia small. Pulvilli not traceable. Claws with each 1 large and small tooth.

Abdomen. Setose except sternite 1. Male segment 8 very short. Light, weakly pigmented lateral lines (folds?) present on male tergites 2–6 and at least sternites 5–6, and female tergites 2–5 and at least sternite 5.

Male terminalia. Small, not rotated. Sternite 9 not traceable. Tergite 9 separate from gonocoxites, short and wide, consisting usually of 2 large sclerotized portions interconnected by narrow membranous portion, sclerotized portions setose. Gonocoxites broadly merged ventrobasally (= basal portion), with narrow ventrolateral processes projecting beyond gonostyli; each process with 1 short apical and 1 subapical seta. PostGA and antGA long. Gonostylus with large main body arising from basal stalk, the latter with dorsal setae, the former with numerous short, blunt macrosetae directed mesally. Ejaculatory apodeme absent. Parameres merged to form tegmen; parameral apodemes well developed, directed ventrolaterally. Hypoproct with 4 setae. Cerci largely fused, rounded apically, setose. Female terminalia. Short. Tergite 8 large, setose. Gonocoxite 8 rounded apically, with large setae. Tergite 9 not traceable. Gonapophyses 9 merged to form small, weakly sclerotized internal structure. Tergite 10 very short, setose. Sternite 10 very narrow, setose. Hypoproct unusually large, setose apically. Cercus setose, basicercus longer than disticercus.

Variation. The extent of infraspecific variation in Sigmoleia is remarkable, in particular with respect to body size, antenna length, and outline and relative length of Rs and M1. Unlike in the Sigmoleia species from New Caledonia (see Matile 1993), interspecific differences in leg coloration are not apparent in the species from New Zealand.

Figures

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 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 13 – 18. Wings. 13: Paradoxa fusca Marshall, dorsal view. 14: Sigmoleia melanoxantha Edwards, ventral view. 15: Sigmoleia similis sp. n., ventral view. 16: Sigmoleia separata sp. n., dorsal view. 17: Sigmoleia peterjohnsi sp. n., vental view. 18: Cycloneura triangulata Tonnoir, ventral view.