Enicoscolus brachycephalus Hardy, 1961

Amorim, Dalton De Souza & Pinto, Lenira Guimar à Es, 2004, First known male of Enicoscolus (Diptera: Bibionidae), with a redescription of E. brachycephalus, Zootaxa 665, pp. 1-8 : 2-5

Enicoscolus brachycephalus Hardy, 1961

( Figures 1–9 )

Enicoscolus brachycephalus Hardy, 1961: 82 , figs. 2a–e (head, legs, thorax, wing). Type­locality: Mexico, Morelos, Tepotzlan. Distribution: central and southern Mexico.

Material examined. Two males, MEXICO, State of Morelos, Cuernavaca, x.1965, N.L.H. Kraus col.; 1 female, MEXICO, State of Oaxaca, Oaxaca, Base San Felipe Mt., Sept. 16– 17, 1947, B. Malkin ( AMNH).

Diagnosis. Wings fumose, basal interruption of CuA1 longer than in E. dolichocephalus , rostrum not very elongated.

Redescription

Female. Total length 5.98, wing length, 4.27, wing width, 1.83, mesonotum length, 1.95. Head shining blackish brown, scutum and abdomen dark brown. Pleural sclerites lighter than scutum, legs shining brown, lighter to the apex. Wings fumose.

Head. Slightly elongated, rostrum slightly projected, mouthparts in a ventro­anterior position relative to the head length. Eyes strongly dichoptic, hemispherical. Antenna quite short, 0.37, flagellum 6­segmented, distal four flagellomeres short, rather clavate, flagellomeres 4 and 5 nearly fused. Maxillary palpus elongated, 0.59, 5­segmented, palpomeres 2–3 with a mesal constriction, palpomere 3 with dorsal sensorial setae, last palpomere thin and elongated. Ocelli on a tubercle, with scattered post­ocellar setae, no particularly developed setae on occiput.

Thorax. Mesonotum elongated, antepronotum and scutum with some scattered setae developed into small spines. No setae on pleural sclerites except for 11–14 anepisternals and 2–4 setulae on mesepisternum.

Legs. Front leg more developed and mid and hind legs, coxa large, femur strongly inflated, tibia with mucron projected beyond insertion of the tarsus, tibial spur present. Mid and hind coxae short, compared with fore coxa, mid and hind tibial spurs well developed. Mid femur and tibia slightly clavate. Hind femur and tibia elongated, femur slightly inflated, tibia clavate, hind first tarsomere slightly enlarged at the apex, as noted by Fitzgerald (1997). Leg measurements. Front leg, coxa, 0.63; femur, 0.80; tibia, 0.71; tarsus, 1.39; first tarsomere, 0.56. Mid leg, coxa, 0.44; femur, 0.76; tibia, 0.63; tarsus, 1.15; first tarsomere, 0.37. Hind leg, coxa, 0.27; femur, 1.17; tibia, 1.15; tarsus, 1.15; first tarsomere, 0.39.

Wing. Membrane fumose, Sc incomplete, M1+2 very short, nearly fused to Rs, base of CuA1 largely interrupted, fork of Rs displaced to the apex, as in other Bibionini. Macrotrichia dorsally on R1 and on distal section of Rs.

Abdomen. Tergites and sternites sclerotized, but slightly reduced in size, membrane reticulate.

Female terminalia. Three rounded, sclerotized spermathecae, T8+9 rather reduced in size, membranes on segment 8 well developed, gonapophyses 8 lobose, with more concentrated and elongated setae, genital furca weakly sclerotized, T10 and S10 not strongly sclerotized but present, cercus elongated, covered with setae and microtrichia, 1­segmented.

Male. Smaller in size than females, total length, 3.54, wing length, 2.93, wing width, 1.10, mesonotum length, 1.10. Head shining dark blackish brown, scutum and abdomen dull blackish brown. Pleural sclerites dark brown, legs shining brown, slightly lighter to the apex. Head more rounded, not particularly elongated ( Figure 1 ), holoptic, eyes touching in the middle, ocelli on a small tubercle, rostrum only slightly projected. Last palpomere not so elongated than in females, antenna clavate, flagellum 5­segmented. Thorax mostly blackish ( Figure 2 ), general shape of legs as in females ( Figure 4 ). Leg measurements. Front leg, coxa, 0.52; femur, 0.54; tibia, 0.59; tarsus, 1.02; first tarsomere, 0.37. Mid leg, coxa, 0.22; femur, 0.49; tibia, 0.27; tarsus, 0.80; first tarsomere, 0.27. Hind leg, coxa, 0.22; femur, 0.76; tibia, 0.80; tarsus, 0.85; first tarsomere, 0.32. Wing ( Figure 3 ), no dorsal or ventral macrotrichia on wing veins. Male terminalia. Gc fused to S9 to form a single plate, distal end of Gc slightly projected distally to S9, Gs simple, parameres absent ( Figures 5–8 ), T9+10 present, relatively small, cerci present, lobose.

Figures

FIGURE 1. Enicoscolus brachycephalus, male, head. Abbreviations: clyp, clypeus; fr, frons; gn, gena; mx plp, maxillary palpus; ped, pedicel; scp, scape; st, stipes; tnt, tentorium.

FIGURE 2. Enicoscolus brachycephalus, male, thorax. Abbreviations: a sp, anterior spiracle; an, anepisternum; c mb, cervical membrane; cx, coxa (I – III); em I, proepimeron; em II, mesepimeron; ep I, proepisternum; ep III, metepisternum; kt, katepisternum; lt, laterotergite; md, mediotergite; mn, metanotum; occ, occiput; p sp, posterior spiracle; pn, pronotum; pn p, postnotal phragma; s I, sternite I; scl, scutellum.

FIGURE 3. Enicoscolus brachycephalus, male, wing.

FIGURE 4. Enicoscolus brachycephalus, male, front leg.

FIGURE 5 – 8. E. brachycephalus, male. 5. Male terminalia, ventral view. 6. Male terminalia, dorsal view. 7. Tegmen and genital rod. 8. Gonostyle. Abbreviations: ce, cercus; gc, gonocoxite; gs, gonostyle; gn r, genital rod; gx ap, gonocoxal apodeme; S 9, sternite 9; T 9, tergite 9; tg, tegmen.

FIGURE 9. E. brachycephalus, male, female terminalia. Abbreviations: ce, cercus; gp VIII, gonapophysis 8; spm, spermathecae; T 9, tergite 9; S 10, sternite 10; T 8, tergite 8.