Heterotropus diamantis Greathead, 2006

Greathead, David J., 2006, New records of Namibian Bombyliidae (Diptera), with notes on some genera and descriptions of new species, Zootaxa 1149 (1), pp. 1-88 : 8-10

Heterotropus diamantis Greathead sp. nov.

Although the specimens described here are in poor condition, having been dried after storage in preservative, they clearly represent a new species distinct from any of those from southern Africa keyed in Yeates & Irwin (1992). The males are similar in appearance to H. posthus but the head and antennae are yellow­brown not black, holoptic not dichoptic, the aedeagus is bifid not trifid and the gonostyli lack median arms. The females are similar to those of H. munroi but their heads are entirely yellow and the frons much broader. It should be noted that the colours may have been altered and the thoracic pattern of the females may have been affected by shrinking of the underlying musculature.

Description. Holotype ♂. Size: length 4 mm; wing, 3.5 mm. Head: yellow­brown; sparse hairs on ocellar triangle, occiput and underside, white. Eyes with facets enlarged in upper two thirds, holoptic with eyes in contact for a distance equal to the length of the ocellar triangle then diverging at an angle of about 30°. Oral margin produced, rim­like. Antennae with scape 1½ length of pedicel; first flagellomere elongate, tapered from the basal third, second only slightly longer than wide, half length of style. Proboscis robust, labellae projecting beyond oral rim and with a few transparent hairs; palpi concealed in oral cavity, yellow and with sparse white hairs. Thorax: Yellow­brown but dorsal surface of mesonotum dull black with a pair of parallel pale lines; also with long white hairs. Legs: femora brown with yellow apices, tibiae yellow, first tarsomere yellow and brown at apex, remainder brown. Femora without bristles, tibiae and tarsi with short, fine, colourless bristles. Claws straight yellow, curved at the apices and blackened; pulvilli ¾ length of claws. Wing: opalescent hyaline, veins pale yellow; r­m cross­vein at apical ¼ of cell dm, cell dm ½ length of bm, anal cell closed just before margin. Squama white. Haltere pale yellow­brown. Abdomen: terga shining brownish­black and with yellow posterior margins from second; long white hairs, dense at sides. Sterna blackish­brown in middle, paler at margins and with sparse white hairs. Genitalia ( Fig. 2 ), gonocoxa with a long dorsal process, gonostylus without a median arm, aedeagus with two prongs only.

Females. Size: length; of body, 5 mm; of wing, 4.5 mm. Head: yellow, frons bulbous and with parallel sides, four times width of ocellar triangle. Face produced spout­like, otherwise as male. Thorax: yellow with a broad median black stripe to level of wings and a pair of lateral stripes extending from level of posterior margin of humeral callus to scutellum and with a small black spot at base of scutellum. Apparently devoid of hairs. Legs and wing as male. Abdomen: terga yellow and with narrow black fore margins and minute sparse white hairs, also with a median and two lateral rows of black spots on first to sixth, seventh entirely yellow. Sterna yellow.

Material examined. Holotype ♂, Namibia: Diamond Area 1, Kaukasib Riverbed, 26°53’S 15°25’E, 10–22.viii.1983, J. Irish & E. Griffin, preserv. traps, H61199 . Paratypes; same data as holotype, 2♂♂, 4♀♀ , same data except. H61198; 3♂♂ , Diamond Area 1, Kaukasib Riverbed, 26°53’S 15°25’E, 10–22.viii.1983, J. Irish & E. Griffin, preserv. traps, H61199; 4♀♀ , same data, H61198; 1♀ , Lüderitz District , Klinghardt Mountains at: 27°21’13”S 15°42’54”E, 27.viii–4.ix.1998, E. Marais & A.H. Kirk­Spriggs, Malaise trap sample; 1♀ , Lüderitz District , 8km W Rosh Pinah, 27°59’28”S 16°39’14”E, 25– 26.iii.1998, A.H. Kirk­Spriggs & E. Marais, yellow pans; 1♀ , Lüderitz District , Tsaukhaib Mountains at: 28°42’58”S 15°41’03”E, 28.viii–1.ix.1998, E. Marais & A.H. Kirk­Spriggs, Malaise trap sample (all NMNW) .

Another female specimen, similar to the paratypes, is probably a specimen of H. diamantis but the antennal flagellum is black, the mesonotum is black across the front only, and the anal cell is narrowed but open at the margin.

Material examined. Namibia : 1♀, Lüderitz District , Obib waters at: 28°00’08”S 16°38’46”E, 25–26.viii.1998, E. Marais & A.H. Kirk­Spriggs, yellow pan trap sample, 1 ♀ ( NMNW) .

Figures

FIGURES 1–4. Genitalia. 1, Apolysis hesseana Evenhuis & Greathead, male genitalia, lateral aspect; 2, Heterotropus diamantis sp. nov., male genitalia, lateral aspect; 3, H. munroi Bezzi, male genitalia, lateral aspect; 4, same spermathecal bulb. Scale bar = 0.1 mm, figures 1 and 4; 0.2 mm, figures 2 and 3.