Dacus (Lophodacus) acutus White & Goodger, 2009, sp.n.

Dacus (Lophodacus) acutus sp.n.

Figures 71 – 77.

Diagnosis. Differs from D. seguyi in having a red-brown (fig. 71) rather than black scutum, and a very deep costal band (fig. 77). The aculeus is pointed (fig. 73), with no torsion, whereas that of D. seguyi has a small preapical “shoulder”, and appears to have torsion.

Description. Size. Small, wing length, 5.1 – 7.0 mm. Head (fig. 74). Pedicel+first flagellomere not longer than ptilinal suture. Face, antennal furrow with a dark spot; taller than broad, usually subrectangular. Frons, frontal setae 2, orbital setae 1 – 2. Thorax (figs 71, 75). Scutum predominantly red-brown, with indistinct pre- and postsutural fuscous areas, usually divided medially; postpronotal lobe yellow; notopleural callus yellow; notopleural xanthine wedge shaped (connected to notopleural callus); lateral and medial postsutural vitta absent. Scutellum without any dark patterning (except for basal dark margin which may be deep). Anepisternum with a narrow yellow stripe from notopleural callus to katepisternum; extended onto katepisternum. Laterotergal xanthine confined to katatergite. Thoracic setae. Anterior notopleural seta present; anterior supra-alar seta absent. Wing (fig. 77). Basal cells bc and c without an almost complete covering of microtrichia; cell bm without microtrichia; narrow subbasal raised section of cell br with extensive covering of microtrichia, apically confined to anterior two-thirds. Crossvein R-M beyond middle of cell dm. Costal band complete; fairly deep, extending below vein R2+3, sometimes to vein R4+5, before wing apex; apically expanded into a large spot, almost reaching vein M; spot starts from near end of vein R2+3. Anal streak absent. Without any crossbanding. Legs (fig. 76). Femora bicoloured; fore- and midfemur red-brown in at least apical three-quarters, yellow basally; hindfemur red-brown in apical half to two-thirds, yellow basally. Abdomen (fig. 72). Predominantly red-brown, with fuscous areas; tergite II usually yellowish apically; tergite III fuscous except for small apico-medial area; terga IV – V with subrectangular lateral fuscous area; fuscous to black midline on terga III – V. Tergites I – V all fused. Male. Tergite III with pecten, dense microtrichia adjacent end A1+Cu2, and hindtibia with a slight preapical swelling. Female (fig. 73). Aculeus pointed; no torsion.

Etymology. Descriptive name for its pointed (acutus) aculeus.

Material. Holotype male, paratypes, 2 females, NIGERIA: Plateau State, Kurra Falls, 60km s.e. Jos, 5 – 7.xii.1987, A. Freidberg (TAU) [labelled with IMW DB record numbers HT 5498; PTs 5751, 5968]; paratype, 1 female, NIGERIA, Jos-Kaduna, Rt.A236, 500 – 1000m., 10.xii.1987, A. Freidberg (TAU).

Remarks. This specimen principally differs from D. seguyi by having a very deep costal band (depth extending to R4+5, or almost so), and a large apical spot (reaching or almost reaching vein M); its scutum is redbrown (black in D. seguyi) and the aculeus apex is a simple point (there are small preapical “shoulders” in D. seguyi). There is a marked size difference between the holotype male (WL = 5.1 mm) and the paratype females (5.8 – 7.0 mm).