Bama (Bama) bickeli, McAlpine, 2015

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 : 41-42

Bama (Bama) bickeli n.sp.

Figs 27–32

Type material. Holotype ♂. Madang Province: Mount Wilhelm , 2200 m, 5.7590°S 145.1861°E, Malaise, 17– 18.x.2012, IBISCA Niugini P 2607 ( MNHN). On micropin through polyporus . Paratypes (all Madang Province): 4♂♂, 3♀♀, same locality as holotype, 17–22.x.2012, IBISCA- P2607, -P2595, -P2563 ( AM, MNHN) ; 2♂♂, 2♀♀, Mount Wilhelm , 2200 m, 5.7593°S 145.2356°E, 25–27.x.2012, IBISCA-P2168, -P2169, -P2216 ( BMNH, MNHN) ; 1♀, same locality, but 7–8.xi.2012, IBISCA-P2229 ( MNHN) ; 2♀♀, Mount Wilhelm , 2200 m, 5.7609°S 145.2353°E, 27.x.2012 – 2. xi.2012, IBISCA-P2202, -P2207 ( MNHN) ; 1 ♂, Mount Wilhelm vicinity, 2012, no other data ( AM) . All specimens obtained during the IBISCA Niugini 2012–2013 expedition .

Description (♂, ♀). Slightly elongate black fly, with heavily marked, sexually dimorphic wing.

Coloration. Head largely blackish; face and at least part of cheek region tawny brown; postorbital to postgenal zone and smaller upper parafacial zone silvery pruinescent. Antenna tawny with brown suffusions; arista becoming black beyond base. Prelabrum brown; palpus grey-brown, with variable tawny suffusions. Thorax black dorsally, pleura black to brown-black. Legs: fore coxa dark brown; hind coxa tawny; mid coxa usually partly tawny, partly brown; fore femur yellow basally, brown on c. distal third to half; mid and hind femora yellow, with narrowly brown apices; tibiae and tarsi dark brown to black. Wing of female with brown to black markings as in Fig. 28 ; that of male ( Fig. 27 ) with less extensive dark markings, in particular distal extremity of marginal cell without blackish zone, distal blackish zone in submarginal cell reduced to little more than a stripe along vein 3 and some yellowish to brown suffusion, dark transverse zone between two hyaline zones in first basal cell much reduced, central pale longitudinal stripe in first posterior cell usually more distinct than in female, and narrow pale line on each side of distal parts of veins 3 and 4 usually more distinct; halter creamy white. Abdomen largely black; tergites without paler zones.

Head. Postfrons almost parallel-sided, near mid-length 0.38–0.39× as wide as head; height of cheek 0.19–0.23 of height of eye; face in profile largely concave, becoming very slightly convex below; posterior fronto-orbital bristle moderately large, anterior one smaller; postvertical bristles small or vestigial, often not forming a symmetrical pair. Antennal segment 3 c. 2.6× as long as deep, narrowly rounded apically; segment 4 short but distinct; segment 5 c. as long as its diameter; segment 6 strongly tapered over short section beyond cylindrical basal section, coarsely pubescent over entire length except for that basal section. Prelabrum moderately developed, convex in profile; palpus not broadened distally, distinctly longer in male than in female.

Thorax. Mesoscutum bare and glossy between setulae on central part, with gradually increased pruinescence laterally, including that on humeral callus; scutellum pubescent on almost entire dorsal surface, glossy laterally; mesopleuron largely glossy, with little pruinescence near upper margin; prescutellar acrostichal and dorsocentral bristle of moderate size, almost transversely aligned. Fore femur with several moderately long posteroventral and posterodorsal bristles, often one or more of former somewhat thickened; mid coxa ( Fig. 29 ) with distomedial lobe prominent, broadly rounded with flat surface, its margin otherwise with very irregular comb of mostly black setulae; hind basitarsus slender, cylindrical in female, in male ( Fig. 30 ) broadened and compressed, its length 0.57 of length of hind tibia. Wing: most of first costal cell and basal zone of second costal cell bare; stem vein with small non-linear dorsal group of setulae; vein 2 with moderate curve near level of anterior crossvein so that submarginal cell widens from that level; second section of vein 4 almost straight; penultimate section of vein 4 c. as long as anterior crossvein, more than half as long as discal crossvein; large basal zone in first basal cell densely microtrichose, hyaline zone just beyond this largely bare; second basal cell with some microtrichia distally; anal cell almost bare; anal crossvein strongly bent near anterior end, almost straight or with slight concave curvature elsewhere.

Abdomen. Female: length of compound tergite 1+2 c. 0.8 of that of tergite 3; tergites 4 and 5 vestigial; sternites 2 and 3 large; sternite 1 slightly shorter; sternite 4 less than one third as long as sternite 3, transverse; sternites 5 and 6 very short, but sclerotized and setulose. Male: sternite 4 large, with very deep median cleft ( Fig. 31 ); aedeagus ( Fig. 32 ) with slender, almost undifferentiated preglans, and short simple flexible section; glans ovoid, with membranous subquadrate distal lobe and two narrow lobes associated with base of bulb; bulb slender, elongate, sclerotised, almost as long as glans; left terminal filament moderately elongate, slightly longer than glans; right terminal filament slightly shorter than glans.

Dimensions. Total length, ♂ 5.8–6.6 mm, ♀ 5.1–6.1 mm; length of thorax, ♂ 2.5–2.6 mm, ♀ 2.5–2.9 mm; length of wing, ♂ 6.8–7.0 mm, ♀ 6.7–7.1 mm; length of glans of aedeagus, 0.28–0.30 mm.

Notes. Bama bickeli approaches B. monstrans and B. papuanum in general appearance, including its dark body coloration, wing venation, and wing pattern, the last with a degree of sexual dimorphism. However, the male differs from those two species in its broadened hind basitarsus and absence of a lobe on the preglans of the aedeagus, while both sexes have a more generalized mid coxa.

The specific epithet refers to Daniel J. Bickel who arranged for access to material of this species and other interesting platystomatids collected by the IBISCA Niugini 2012–2013 expedition (a module of Our Planet Reviewed Papua New Guinea), in which he co-operated.

Figures

Figures 27–29. Bama bickeli n.sp. (27) Left wing of holotype male. (28) Left wing of female. (29) Mid coxae and adjacent parts of female, anteroventral view.

Figures 30–32.Bama bickeli n.sp.(30) Right hind tibia and tarsus of male.(31) Abdomen of male, right