Phycus Walker, 1850

Lyneborg, Leif, 1987, Notes on the Phycini of southern Africa with the description of a new genus and two new species (Diptera: Therevidae: Phycinae), ANNALS OF THE NATAL MUSEUM 28 (2), pp. 467-474 : 469-470

Genus Phycus Walker

Phycus Walker, 1850:2 .

Type srecies: Xylophagus canescens Walker, 1848 (= Xylophagus brunneus Wiedemann, 1824 ), origina monotypy.

For full synonymy: see Lyneborg (1978: 212, 1983: 185).

Diagnosis

Medium-sized to large, blackish or rarely yellowish, slender-bodied species. Eyes separated in both sexes, frons being wider in ♀ than in ♂. Frontal pattern composed of shining black and greyish tomentose areas. Face and gena free of pile. Scape and first flageliomere varying greatly in proportions among species ( Figs 1-5 ), but in the species of southern Africa scape is shorter than i of first flagellomere and provided with strong setae ventrally, sometimes also dorsally. Flagellar style apical, two-segmented, with a minute spine apically. Palpus twosegmented, apical segment shorter than basal segment. Only 1,2 (or 3) notopleural setae. One pair of scutellar setae. Ambient vein continuing to AI' Prosternum and posterior surface of mid coxa without pile. All femora without setae. Tibiae with very short setae.

♂: epandrium simple; ventral epandrial sderite complete and well sderotised, as long as epandrium. Gonocoxites not fused ventrally; hypandrium vestigial or absent. Ventral lobe of gonocoxite absent. Aedeagus with strong dorsal bridge to dorsal edge of gonocoxite.

♀: two small vestiges of T9 present. TIO divided into two sderites, each with some moderately strong, upwardly directed setae. Cerci oval, well separated. S10 separate from hypoproct, which is divided.

Distribution

Afrotropical Region except the equatorial rain-forest area. Also North Africa, Middle East, Iran, Pakistan, India, Sri Lanka, Further India (Burma, Thailand, Cambodia, Vietnam and continental Malaysia), Indonesia, the Philippines, and Taiwan. Also one undescribed species in south-western U.S. A.

Key to species of southern African Phycus

1 Abdomen entirely yellowish. All femora yellowish.................... 2

Abdomen, or at least the last segments, blackish. Femora at least partly darkened. ... ... .. ... .. ... .. .. ... .. .. .. .. .. .. .. .. .. ... .. ... ... ... 3

2 Scape with dorsal setae ( Fig. 5 ). First flagellomere ( Fig. 5 ) partly yellowish. Palpi yellowish................................... .. fulvus Lyneborg ♀

Scape with only short pile dorsally ( Fig. 4 ). First flagellomere ( Fig. 4 ) entirely black. Palpi dark brown.......................... .. f1avus Lyneborg ♂ ♀

3 Scape with strong setae both dorsally and ventrally ( Figs 1-2 ). All femora uniformly blackish. Sparse pilosity present on upper sternopleuron... ... 4

Scape with ventral setae only ( Fig. 3 ). Mid and hind femora distinctly paler than the blackish front femora. Pilosity absent from upper sternopleuron mirabilis Lyneborg ♂ ♀

4 Frontal callus separated from ocellar callus by a narrow strip of tomentum, and also well separated from eye-margin............. .. niger (Krober) ♂ ♀

Frontal callus broadly confluent with ocellar callus and broadly touching eye-margins ...................................... kroeberi (Brauns) ♀ Notes on the species

Phycus niger (Krbber) is a widespread species in Namibia. For example, it occurred abundantly at Gobabeb in February 1974, appearing on dead and dying tree-trunks in riverine habitats at the Kuiseb river. New South African record: Cape Province, 20, Richtersveld, Numees Mine, 28°18'S, 16°58'E, 16- 20. ii. 1979, Malaise trap, Lamoral, Bampton, Barnley (NM).

Phycus kroeberi (Brauns) is closely related to niger , and is still only known from two female specimens collected at Willowmore in December 1913. The lectotype is deposited in the NM.

Phycus mirabilis Lyneborg was originally described and hitherto known only from Zimbabwe. New records of this handsome species are: BOTSWANA: 1♂, SE2226BD, Farmers Brigade 5 km SE of Serowe Hillside, 6.v.1984, mercury vapour lamp, P. Forchhammer ( NM) . SOUTH AFRICA: Natal, 4♂, Lebombo foothills , 2732AC, 5 km N Jozini, under fig tree, 28.viii.1982, B. Stuckenberg ( NM & ZMC) .

Phycus flavus Lyneborg is still known only from a male holotype and a female paratype from NE Transvaal. It is closely related to mirabilis , but with yellow abdomen and different genitalia.

Phycus fulvus Lyneborg is known from two female specimens from Namibia.

For descriptions and illustrations of these species, see Lyneborg ( 1978).

Figures

Figs 1-5. Antennae of Phycus species of southern Africa. 1. kroeberi (Brauns). 2. niger (Krober). 3. mirabilis Lyneborg. 4. flavus Lyneborg. 5. fulvus Lyneborg. Scale: 0,5 mm.