Redescription of adults

Male (Figs 1, 3a, 5, 6, 14b): Head (Figs 1b, 5): Vertex brownish, with scattered setae, yellowish around eyes. Two ocelli medially on blackish vertex. Frons light brown. Face and clypeus yellowish, covered with setulae. Labellum yellowish, ventrally darker; maxillary palpus brownish, apical segment lighter, segments 3-5 of similar length, first two segments short. Scape and pedicel yellow, rounded, more setose anteriorly; flagellum brown, antenna shorter than thorax, flagellomeres slightly longer than wide. Thorax (Fig. 5): Prosternum brownish. Pronotum yellow, with strong, long, black bristles. Proepisternum yellow, proepimeron brownish posteriorly, both bare. Anepisternum yellow anteriorly with large brown macula on posterior two thirds, bare. Katepisternum yellow on dorsal third, large brown macula occupying ventral two thirds, bare. Mesepimeron yellow, posterior margin brownish, bare. Laterotergite mostly yellow, anterodorsal margin brownish, bare. Mediotergite yellow ventrally, a brownish triangular mark dorsally, bare. Meso- and metapleura yellow, entirely bare. Scutum yellow, with five brown stripes fusing posteriorly, covered with short and long setae, a pair of stronger dorsocentral and a pair of stronger dorsolateral setae posteriorly. Scutellum yellow, with a pair of long scutellar bristles and a few scattered setulae. Legs yellow; forecoxa with some brownish maculae anteriorly, with strong setae in a line on its posterior and ventral margins; tibial setae regularly aligned; tibial spur I almost twice length of tibial diameter at apex, tibial spurs II and III almost four times length of tibial diameter at apex. Halter stem whitish, knob black, setose. Wing (Fig. 3a): Wing venation and color pattern as in the Fig. 3a. Abdomen (Figs 1, 14b): Tergites and sternites mostly yellow; T1 brown posteromedially; T2 brown anteromedially; T3 brown, but yellow laterally; T4 and T6 brown medially, yellow posterolaterally; T5 brown with yellow posterior margin; T7 mostly yellow; sternites mostly yellow, sternites 3 and 5 with brown areas on its surface. Terminalia (Fig. 6): Yellow. T9 weakly developed and sclerotized, with a few setae distally (Fig. 6C). Gonocoxite with large dorsal projection extending beyond apex of gonostylus, densely covered with setae on external face, apex digitiform, mostly bare, a few small setae at apex. Gonostylus well developed, deeply bifid, inner branch secondarily bifid and nearly bare, a few small spines on inner margin, external branch strongly setose. Gonocoxal apodeme short, sclerotized; parameres strongly developed, with a dorsal, membranous, bare projection; cercus and S10 rounded, with some small setae distally (Fig. 6D).

Female (Figs 2, 3b, 4). Similar to male, except as follows: hind coxa with brownish maculae; hind femur browner distally; abdomen yellower (Fig. 2). Wing venation and color pattern as in Fig. 3b. Terminalia (Fig. 4). Yellow. Sternite 8 covered with setae, inner margin slightly concave, with a pair of spine-like setae; tergite 8 covered with microtrichia, bare of setae; genital fork well developed, reaching segment 7 anteriorly; cercus short, apical cercomere rounded, ~¼ length of basal cercomere.

Mature larva [Probably fourth instar larva] (Figs 7, 8, 9, 11, 12, 15b). Length: 18.8 mm. General body shape cylindrical, no projections, creamy white in color, whiter in prepupal stage (Fig. 12), 12 apparent segments, segments 4-8 wider and longer than remaining ones.

Head capsule relatively well sclerotized (Figs 7, 8, 9, 12c, d), bare, subrectangular, (anterior end slightly more slender than posterior end, as in the larvae of other mycetophilid genera, e.g., Brachypeza Winnertz—see Madwar 1937) and at least partially retractable into first segment. Separation between dorsal plates of head capsule not clearly evident, medial plate extending almost to the posterior capsule margin. Eye posterolateral to the antenna (Figs 7, 9). Occipital foramen ventrally triangular, at about distal fourth of head capsule. Mouthparts occupying ~1/3 of anterior head capsule. Labrum wide, fleshy. Premandible with row of elongated, flexible teeth, supported by a pair of lateral chitinous arms. Mandible semicircular and bearing two rows of medially directed teeth (Fig. 8b) as found in other Mycomyiini species (Krivosheina and Zaitzev 2008). Maxilla with rounded, medially directed, edge bearing a row of medially directed teeth (Figs 8b, 9).

One pair of prothoracic, and seven pairs of abdominal, lateral spiracles; prothoracic spiracle only slightly larger than abdominal ones. Spiracles on short, scale-like sclerite with a couple of small openings. Intersegmental areas with creeping welts (fleshy lobes slightly elongated across the body bearing rows of denticles – Fig. 15b). Each creeping welt includes part of an anterior and a posterior segment, the anterior portion bears fewer, short rows of sparse denticles, the posterior part bears more rows of dense denticles. Posterior end of abdomen with a fleshy lobe folded ventrally.

Pupa (Figs 13, 14a, 15a). Brown to dark brown, suspended in a web connected by silk lines attached to the entire body, last larval skin remains attached to abdomen posteriorly. Head strongly united with the thorax; developing antennae visible, curved over eyes. Thorax with protruding processes laterally on scutal margin; wing sheath extending just beyond half of abdomen; developing legs held together along ventromedial margin of abdomen. All spiracles flat, flush with surface, not on protrusions. Dorsal margin of abdomen flat.

Adults. Laterotergite mostly yellow, anterodorsal margin brownish, bare. Mediotergite yellow ventrally, a brownish triangular mark dorsally, bare. Gonocoxite with large dorsal projection extending beyond apex of gonostylus; gonostylus well developed, deeply bifid, inner branch secondarily bifid and nearly bare, a few small spines on inner margin, external branch strongly setose; parameres strongly developed, with a dorsal, membranous, bare projection. Female apical cercomere rounded, ~¼ length of basal cercomere.

Larvae were found on two different species of polypore fungus, indicating that this species can feed on multiple fungi species, as found in other genera of the family (Hutson et al. 1980, Ševčík 2010). All larvae were collected with the fungus fruiting bodies they were feeding on; those from São Paulo state (all reared material female) were feeding on an uncertain species of Sparassis (Polyporales: Sparassidaceae) (Fig. 10a), and those from Goiânia (all reared material male) were collected on an undetermined species of Polyporaceae (Fig. 10b). Both fungi were determined by J.M. Baltazar in vii.2013 using photographs (Fig. 10).

Larvae of N. puncticoxa crawled over the surface of the fungal fruiting body (sporocarp), moving along slime trails and silk lines (Fig. 11) they produced. Those on the Sparassis sp. often had webs and slime trails suspended between the lamellae of the fungus. The specimens collected on the polypore from Goiânia spent most of their time feeding on the pore surface (underside) of the fungus. It was not observed whether they dig into either sporocarp or not, though there were numerous small holes on the fungus in the region where the larvae were residing. It is probable that they were ingesting the sporulating surfaces of the sporocarp. In preparation for pupation the larvae spun an irregular web, approximating a loosely woven cocoon, and then pupated in the centre of that cocoon, hanging over the substrate with the ventral part of the body facing downwards (Figs 12, 13, 14a). The droplets present on the web strands (Figs 12d, 14a) may be acidic and serve a protective function, as seen in other Sciaroidea (Plachter 1979b, Matile 1997), though this was not tested in our study.

Edwards (1940) and Coher (1959) both mentioned morphological variation between males and females of N. puncticoxa. Coher (1959) highlighted that the pleural marks in females were more pronounced than in the males. We observed the same range of variation in the material we reared (Figs 2, 14b).