Nervijuncta laffooni Lane, 1952

Falaschi, Rafaela Lopes & Amorim, Dalton De Souza, 2009, Review of the Neotropical species of Nervijuncta Marshall, 1896 (Diptera, Ditomyiidae), Zootaxa 2219, pp. 18-30 : 20-24

Nervijuncta laffooni Lane, 1952

( Figs. 1–8 )

N. laffooni Lane, 1952: 139 (new name for N. marshalli Lane ). Type-locality: Brazil, State of São Paulo, Salesópolis, Estação Biológica de Boracéia. Distr. – Brazil (São Paulo, Santa Catarina). Holotype 3, MZUSP. Ref. – Papavero 1977: 4 (catalogue).

N. marshalli Lane, 1948: 250 , figs. 5 (male terminalia), 6 (detail of T9 and cerci), 7 (aedeagus); Lane, 1952: 131 (female) (preocc. Edwards 1927). Type-locality: Brazil, State of São Paulo, Salesópolis, Estação Biológica de Boracéia. Holotype 3, MZUSP. Ref. – Papavero 1977: 4 (catalogue).

N. marshally ; Lane 1952: 131, error.

Diagnosis. Single light area across middle of wing; distal projection of gonocoxites dorsally less than half length of gonocoxite at midline, with a very long distal setae; gonostyli with a wide basal enlargement.

Material examined. Holotype 3, Brazil, State of São Paulo, Salesópolis, Boracéia, 14.viii.1947, Rabello, E., Travassos, F. & Lane, J. col. “Alotype” Ƥ, same data as holotype, but ix.1949, Travassos, E. col. Additional specimens: 1 3, Brazil, State of Santa Catarina, Nova Teutônia, 04.x.1970, 27º11’B, 52º23’L, 300–500 m, Plaumann, F. col; 1 3, Brazil, State of Santa Catarina, Urubici, Morro Igreja, 18.viii.2005 – 06.i.2006, Malaise trap, Pinho, L. & Bizzo, L. col. (all specimens at MZUSP).

Redescription. Male. Body, 6 mm. Wing, 5 mm. Color. Body mostly dark brown, legs and terminalia light brown, yellowish spots basally on abdominal segments. Wings maculate, mostly brownish with a brighter area across middle of wing. Head. Clypeus about twice as wide as long, yellowish, covered with scattered, brownish setulae. Frons narrow, yellowish. Eyes large, strongly emarginated above base of antennae, forming a complete eye-bridge; fine setulae among ommatidia. Three ocelli, mid ocellus minute, lateral ocelli displaced ventrally to nearly touch eye margin. Occiput brownish-yellow, covered with scattered brownish setae. Antenna twice as long as thorax; pedicel, scape and base of first flagellomere light yellow, remaining flagellomeres brownish; flagellomeres with a medial, regular whorl of setae each with large sockets ( Fig. 1 ). Maxillary palpus brownish, with three segments, first segment wider, with numerous, scattered sensillae each with large sockets. Thorax ( Fig. 2 ). Scutum yellow, with three longitudinal brown stripes, with scattered small setae, some larger setae along the dorsocentral lines. Scutellum brownish, yellowish laterally, with two lateral pairs of longer setae. Pleural sclerites brownish, except for the yellowish pronotum and yellowish band along the dorsal half of the katepisternum; katepisternum with three long setae at posterior margin, other sclerites bare. Antepronotum present as a wide stripe anterior to the mesonotum; postpronotum slender, elongate, with a large anterior seta and two small, posterior setae. Proepisternum and proepimeron slender. Primary anapleural suture complete, curved, katepisternum extending dorsally along anterior margin of the anepisternum. Mesepimeron restricted to the dorsal part of the thorax due to the fusion of the katepisternum posteriorly to the laterotergite; laterotergite relatively small, not protruded, mediotergite nearly straight in lateral view. Metepisternum large, but weakly sclerotized, metepimeron scarcely visible. Postnotal phragma short, just ventral to the mediotergite, well sclerotized. Halter light brownish, a yellowish macula on pedicel. Legs. Legs light brown, very long and thin. Fore and mid coxa with elongate setae distally on anterior face, hind coxa with a group of basal posterior setae and some posterior apical setae. Tibiae covered with dark, dense, scattered setae. Front tibial spur almost twice as long as diameter of tibial apex; mid and hind tibial spurs largely unequal in length, the larger one almost twice length of tibial apex, the smaller very short. Wing ( Fig. 3 ). Wing brownish, lighter area across middle of wing. Wing membrane covered with macrotrichia on distal two thirds, basal third more setose on anal lobe; microtrichia covering entire wing membrane. C extending beyond apex of R5; Sc incomplete, not reaching origin of Rs; Rs originating before middle of wing, extending almost straight to point of contact of r-m, distal third of first sector of Rs weakly sclerotized; R4 originating just before apex of R1, not too long, oblique, with an evident angle close to origin; r-m almost absent, base of M1+2 almost fused to Rs; bM entirely absent; M1+2 long, medial fork originating just below base of R4; m-cu long, almost longitudinal; CuA clearly curved close to apex; A1 complete. All posterior wing veins with macrotrichia except first sector of Rs, first sector of CuA, M3+4, m-cu, and basal half of A1. M2, M4 and CuA more sclerotized than M1+2, M1, and A1. Abdomen. Abdomen elongate, segments longer than wide; segments brown with a yellowish basal band on segments II to VII. Terminalia ( Fig. 4–6 ). Gonocoxites fused to each other ventrally, forming a syngonocoxite, but also dorsally; a pair of short, distal dorsal projection of gonocoxites about twice as long as the width, ending in a distinctively long bristle. Gonostyli very long and flattened, tapering to the apex, with a curved tip, inner margin blade-like, with a row of about 100 teeth-like spines, slightly separated from each other, base of gonostylus expanded inwards ( Fig. 5 ). Tegmen longer than wider, rugose laterally; aedeagus with a pair of lateral extensions basally, cupshape at apex ( Fig. 6 ). Tergite 9 small, slightly longer than the width, covering the “opening” left by the dorsal fusion of the gonocoxites; cerci elongated, setose, with a fold at apex forming a distal lobe.

Female. Similar to the male (including size), though lighter markings of mesonotum, halters and abdominal bands. The allotype is missing the head, so the eye-bridge cannot be verified. Terminalia ( Fig. 7 ). Sternite 8 elongated, longer than wide, a deep notch almost dividing sclerite in two, long setae on digitiform projections distally. Tergite 8 well developed. Sternite 9 (vaginal furca) as long as sternite 8, sides of basal extension parallel. Tergite 10 short, sternite 10 not recognizable. Basal segment of cerci short, apical segment short, with apical digitiform projections bearing longer setae.

Comments. N. laffooni has a single lighter area across the first section of Rs, base of M1+2 and base of M4, while the only other Neotropical species of the genus, N. conjuncta , has two light transverse areas across the wing. The gonostyli in N. laffooni are longer than in N. conjuncta , wider at the base and thinner at apex. The distal projections of the gonocoxites dorsal to the insertion of the gonostyli are shorter in N. laffooni , than in N. conjuncta . The head of the only female specimen of N. laffooni is missing, so it is not possible to confirm whether the eye-bridge in females of this species is complete, as in males.

Figures

FIGURE 3. Nervijuncta laffooni (Brazil, Santa Catarina, Urubici), male wing.

FIGURE 4. Nervijuncta laffooni (Brazil, Santa Catarina, Urubici), male terminalia, dorsolateral view. Ae, aedeagus; Ce, cercus; Gc, gonocoxite; Gs, gonostylus; S 8, sternite 8; T 8, tergite 8; T 9, tergite 9; Tg, tegmen.

FIGURES 5 – 6. Nervijuncta laffooni (Brazil, Santa Catarina, Urubici), male. 5. Detail of gonostylus. 6. Detail of aedeagus (Ae) and tegmen (Tg).

FIGURE 7. Nervijuncta laffooni, female (Brazil, São Paulo, Salesópolis). Terminalia, dorsal view. Ce 1, basal segment of cercus; Ce 2, distal segment of cercus; S 8, sternite 8; T 8, tergite 8; T 9, tergite 9; T 10, tergite 10; VF, vaginal furca.

FIGURES 1 – 2. Nervijuncta laffooni (Brazil, Santa Catarina, Urubici), male. 1. Antennal flagellomere. 2. Thorax, lateral view. Abbreviations: ane, anepisternum; apr, antepronotum; asp, anterior spiracle; cx, coxa.; ktp, katepisternum; ltg, laterotergite; mdt, mediotergite; mep, mesepimeron; mes, metepisternum; pem, proepimeron; pes, proepisternum; ppr, postpronotum; pnp, postnotal phragma; psp, posterior spiracle; scl, scutellum; sct, scutum.

FIGURE 8. Nervijuncta conjuncta, male wing (Argentina, Neuquén).