Bama (Bama) signifer McAlpine 2015, n.sp.
Creators: name: McAlpine, David K.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Platystomatidae
Bama
Bama signifer

description: <i>Bama (Bama) signifer</i> n.sp. Figs 17–20 <b>Type material</b>. Holotype ♀ (unique). Milne Bay Province (highlands of NE): Agaun, 4400 feet [c. 1340 m, c. 9°55'S 149°21'E], Aug. 1969, R.P. (ANIC). On micropin through polyporus. <b>Description</b> (♀, ♂ unknown). Slightly elongate brown to blackish fly, with wing heavily marked anteriorly to vein 4. <i>Coloration.</i> Head largely brown, shading to black on vertex and much of occiput, with silvery pruinescence on postorbital to postgenal zone. Antenna tawny-brown; arista becoming darker distally. Prelabrum tawny-brown; palpus grey-brown. Thorax largely dark brown; mesoscutum predominantly shining black. Legs: coxae tawny; mid coxa with larger setulae black, finer ones yellow; femora yellow; tibiae tawny-brown; tarsi darker-brown. Wing (Fig. 17) anteriorly to vein 4 largely brown-black, with first costal and base of second costal cell yellow, extreme base of marginal cell mid-brown, and hyaline zones in first basal and first posterior cells; behind vein 4 membrane largely hyaline, with narrow brown zone in second posterior cell along vein 4 and three small brown zones in discal cell; halter entirely pale yellow. Abdomen dorsally tawny to brownish; tergite 1 and lateral parts of tergite 2 blackish. <i>Head.</i> Postfrons almost parallel-sided, near mid-length c. 0.39× as wide as head; height of cheek c. 0.23 of height of eye; face in profile mainly concave, becoming flat towards lower margin; fronto-orbital bristles apparently rather small (damaged); postvertical bristles very fine, closely placed. Antennal segment 3 c. 2.5× as long as deep, apically rounded; segment 4 prominent, rounded; segment 5 bare, relatively elongate, length distinctly more than twice its maximum diameter; segment 6 (Fig. 19) quite bare, becoming attenuated shortly beyond base, with leaf-like subapical expansion (palette). Prelabrum rather shallow, not prominent; palpus short, moderately broad but not distally expanded. <i>Thorax.</i> Mesoscutum almost bare between setulae on much of dorsal surface, pubescent-pruinescent laterally; scutellum pubescent on entire dorsal surface; mesopleuron partly glossy, with very little pruinescence centrally and posteriorly; prescutellar acrostichal bristle absent; single pair of dorsocentral bristles more closely placed than in other species. Fore femur with stout posteroventral bristles on distal half and smaller posterodorsal bristles; mid coxa with distomedial lobe not narrowly produced, with large and small setulae. Wing (Fig. 17): much of first costal cell and small basal zone of second costal cell bare; stem vein with few minute dorsal setulae; vein 2 curved but not abruptly flexed; second section of vein 4 moderately curved; penultimate section of vein 4 c. as long as anterior crossvein, almost 0.7× as long as discal crossvein; second basal and anal cells and basal hyaline zone in first basal cell largely bare; anal crossvein strongly curved on anterior part, with slight concave curvature posteriorly. <i>Abdomen</i> (Fig. 20). Compound tergite 1+2 subequal in length to tergite 3; sclerotized part of segment 7 (oviscape) almost as long; sternites 1, 2, and 3 large; sternite 4 relatively small; sternites 5 and 6 apparently very short (not clearly visible in type). <i>Dimensions.</i> Total length, 6.0 mm; length of thorax, 2.4 mm; length of wing, 7.0 mm. <b>Notes</b>. The complete absence of prescutellar acrostichal bristles and the bare arista (Fig. 19) distinguish <i>B. signifer</i> from all other known species of <i>Bama</i>. The presence of a subapical palette on the arista is an unusual condition of the female holotype. In males of a number of platystomatid species in several other genera an aristal palette is present, but in these the palette is generally absent in females. In <i>Euprosopia maculipennis</i> (Gúerin-Méneville) the palette is present in both sexes, but smaller in the female. I expect that the presently unknown male of <i>B. signifer</i> will be found to have the palette at least as developed as in the female. The specific epithet is a Latin noun, meaning flag-bearer, in reference to the palette of the arista. One specimen (unsexed, abdomen missing) from Mount Missim, Morobe Province (labelled <i>Bama</i> sp. P, BPB) has the contour of vein 2 and wing markings much as in <i>B. signifer</i>, except that the discal crossvein is enclosed in a brown mark. However, the arista is creamy-white and pubescent on its whole length, without apical expansion. I regard its specific status as indeterminate at present.
description: Published as part of <i>McAlpine, David K., 2015, Signal Flies of the Genus Bama (Diptera: Platystomatidae) in Papua New Guinea, pp. 25-53 in Records of the Australian Museum 67 (2)</i> on page 36, DOI: 10.3853/j.2201-4349.67.2015.1603, http://zenodo.org/record/4684865