Tabanus gratus Loew, 1858

Mugasa, Claire M., Villinger, Jandouwe, Gitau, Joseph, Ndungu, Nelly, Marc Ciosi, & Masiga, Daniel, 2018, Morphological re-description and molecular identification of Tabanidae (Diptera) in East Africa, ZooKeys 769, pp. 117-144 : 117

Tabanus gratus Loew, 1858 Fig. 3F

Location.

Tarangire National Park, Tanzania.

This fly is darker brown, smaller and slenderer than T. taeniola Palisot de Beauvois (1807). However, the colour of T. gratus Loew (1858) collected from Nguruman, Kenya is lighter brown with golden stripes on abdomen.

Descriprion.

Head. Head wider than thorax with slightly concave posterior vertex (Suppl. material 2: Figure S6A). Eyes black with green and black bands when fresh that disappear after the sample dries up. Eyes separated by dark brown frons with black hair. Basal callus dark brown, large and as wide as frons, extending upwards in slender projection connecting with smaller upper tear-drop shaped callus. On each side of upper callus a thick comma-shaped black shade. Long white parafacial hair (Suppl. material 2: Figure S6B). Scape large, light brown with white hair except at tip of the segment with black hair. Pedicel small and brown, more or less covered (obscured) between scape and flagellum, black hair at anterior end. Third segment orange brown with few black hairs. Second palpal segment whitish grey with black and white hair. Labellum brownish grey.

Thorax. Thorax black with black and brown hair; brown median stripe traverses thorax and lateral margins of the scutellum. Sub-lateral stripes greyish brown with golden brown hair. Lateral margins of thorax greyish white. Hair tufts only seen ventrally at the base of wing. White halteres (Suppl. material 2: Figure S6A). Brown fore tibia covered with short white and black hair except anteriorally dark brown covered with black hair. Fore femur brown with black hair and long white hair. Fore tarsus black with black hair. Hind tibia light brown with white and black hair. Hind femur light brown with long white hair. Tarsus yellowish brown with black and white hair. Middle legs same as hind legs. Wing clear and R4 has no appendix (Suppl. material 2: Figure S6C).

Abdomen. Abdomen brown, slender and tapers to the posterior end with black and brown hair, has white median and two lateral stripes pale brownish orange grey, with orange brown part at posterior end of each segment. Stripes have whitish hair. Median stripe narrow in first two segments but widens on the third, widest on the fourth segment before it tapering down to last segment. Lateral stripes wide on first and second segments but gradually narrow as they converge slightly at posterior end of abdomen. Lateral abdominal margins ashy grey (Suppl. material 2: Figure S6A). Ventral abdominal surface brown with white hair.

Figures

Figure 3. Whole tabanid flies. A Ancala fasciata, discal cell (dc) B Tabanus thoracinus, discal cell (dc), haltare (ht) C Tabanus donaldsoni, distinct R 4 appendix (px) D Tabanus taeniola, median stripe (ms), parafacial hair (pf), antennae (at), labellum (lbl), palpus (lp) E Tabanus taeniola variatus, medial triangles (mt), peri-median bands (pm) F Tabanus gratus, haltares (ht), comma shaped shades (cm) G Tabanus guineensis H Atylotus nigromaculatus, eyes with thin black horizontal line (hl) I Atylotus diurnus, haltares (ht), wing with indistinct appendix (px) J Haematopota duttoni K Haematopota fenestralis, double white streak (ds) L Chrysops distinctipennis, hair tufts (hf), bifurcating band (bf).