Bama (Bama) papuanum (Hennig), 2001

McAlpine, David K., 2015, Signal Flies of the Genus Bama (Diptera: Platystomatidae) in Papua New Guinea, Records of the Australian Museum 67 (2), pp. 25-53 : 51-52

Bama (Bama) papuanum (Hennig)

Figs 48–52

Xiria papuana Hennig, 1940: 316–317 , pl. 24, fig. 10.

Xiria strigata Hennig, 1940: 317 , pl. 24, fig. 9. N. Syn. Doubtfully available name—no clearly descriptive statement.

Bama papuanum (Hennig) McAlpine, 2001: 166 .

Bama strigatum (Hennig) McAlpine, 2001: 166 .

Type material. Holotype ♀ of Xiria papuana (given as ♂ by Hennig). Madang Province: “Kaiser Wilhelmsland, Minjemfluss” ( Mindjim River ), no date, R.S. ( SDEI, ex Lichtwardt coll.). Head slightly mouldy; abdomen slightly damaged; right wing mounted on slide . Holotype ♂ of Xiria strigata . Madang Province: identical collection data to those

of X. papuana (SDEI) . Slightly damaged by psocopterans and repaired with glue; aedeagus now in genitalia tube on main pin; right wing mounted on slide. The precise locality on the Mindjim River is not stated, but the river mouth is located at 5°58'S 145°16'E.

Description (♂, ♀). Relatively large blackish fly, with sexually dimorphic dark wing markings; agreeing with description of B. monstrans except as indicated.

Coloration. Head: antenna tawny-yellow. Thorax black to brown-black. Wing markings of female resembling those of B. monstrans , except that discal crossvein lies completely within transverse brown band ( Fig. 48 ); in male distal dark zone reduced to narrow brown margin on costal section from vein 2 to vein 4 and brown stripe on apical part of vein 4 ( Fig. 49 ).

Head. Postfrons near mid-length c. 0.37–0.38 as wide as head; height of cheek 0.23 (male)–0.25 (female) of height of eye. Arista (only intact in female) with slightly longer hairs than in B. monstrans . Prelabrum moderately prominent.

Thorax. Central part of mesoscutum apparently without pruinescence between setulae. Mid coxa ( Fig. 51 ) with relatively weak marginal comb of mainly yellow setulae, medially bearing moderately prominent lobe with flat anterior surface and single stout terminal setula. Wing: penultimate section of vein 4 less than half as long as anterior crossvein; first and second basal cells with somewhat more extensive microtrichiation than in B. monstrans .

Abdomen. Female: tergite 3 slightly longer than compound tergite 1+2; sternites not clearly visible. Male: sternite 4 not observed; aedeagus ( Fig. 52 ) with preglans bearing narrow, acute, leaf-like lobe entirely lacking peg-like spinules; flexible section very short; glans slightly longer than that of B. monstrans , its distal membranous lobe bearing relatively large, rounded sclerite; bulb c. half as long as glans; both terminal filaments much longer than those of B. monstrans , longer (left) filament only slightly shorter than glans.

Dimensions. Total length, ♂ 9.2 mm, ♀ 9.2 mm; length of thorax, ♂ 3.6 mm, ♀ 4.3 mm; length of wing, ♂ 9.0 mm, ♀ 10.0 mm; length of glans of aedeagus, 0.48 mm.

Notes. Hennig (1940) determined the male and female of B. papuanum as separate species, though with an expression of doubt. After careful comparison of Hennig’s two type specimens with both sexes of B. monstrans and other species, I am convinced that the former represent one species, showing sexual dimorphism in wing markings. The slightly stronger curvature of the apical section of vein 4 in the male specimen than in the female is also observed in B. monstrans and in at least some specimens of B. bickeli . The less extensive dark wing markings of the male of B. papuanum than in the female of the species is a more extreme development of the condition also present in B. monstrans , B. bickeli , and B. martini .

The details of the aedeagus, including the proportions of the parts and especially the nature of the lobe of the preglans leave no doubt as to the distinction of B. papuanum from B. monstrans .

Figures

Figures 48–51. Bama papuanum (Hennig). (48) Right wing of female (holotype of X. papuana). (49) Right wing of male (holotype of X. strigata). (50) Humeral region of right wing of female, showing microtrichia on membrane. (51) Mid coxae of male from right side.

Figures 52, 53.(52) Bama papuanum (Hennig), distal part of aedeagus.Scale = 0.2 mm.(53) BamashinonagaiMcAlpine, left wing of holotype, male.bu, bulb;g, glans;lg, distal lobe of glans;pg, lobe of preglans;st, stipe;tf, terminal filaments.