A pretty fly with black and yellow thoraicic markings, lightly patterned wings and technicolour eyes often hogs the lowlight by forest trails, where the insects engage in scintillating displays on leafy platforms. Wings atwitch, forelegs raised and bottoms up, the flies issue quiet challenges to each other with unusual disregard for personal safety, a possible consequence of their vague resemblance to small vespids, though they possess the full power of their tribe to apparate when prodded.
My best, not entirely unresearched, guess as to the identity of these insects is Adrama rufiventris, a tephritid distributed from Thailand to Papua and synomymised, though not always, in the literature with Adrama selecta. Stubby, pendulous antennae; a scutellum with four backward-pointing bristles; a conical ovipositor; and femora bearing a row of ventral spines – these are the visible hallmarks of the genus, whose 13 or more species occur throughout the Orient and Australasia, and which includes Adrama determinata and austeni, two not-insignificant pests of tea seeds. The larval habits of this inland species are not known, but Adrama rufiventris has been obtained from a gutta-percha tree in Thailand, while a congener discovered in local mangroves has been reared from the fruit of Excoecaria agallocha.
Tephritidae, a large family with at least 40 local species, includes the true fruit flies (as opposed to the dipterous lab-rat Drosophila, which favours sour over fresh fruit), a lineage with largely host specific habits, although a few subfamilies have polyphagous, saphrophagic or even parasitoid members. Many tephritids boast colourful ommatidia and smoky cells, the latter of which are employed in showy courtship rituals that may also involve a dab of fragrance from eversible glands. Some species are known to exchange oral fluids in a gesture of reeking intimacy, an act that may be analogous to the presentation of juicy prey by male empidids to their mates. Broadly applicable but frustratingly vague, these observations point to a need to tarry by wayside leks, interpret the fine prints on fresh blades and learn the specific outcomes of these persistent efforts to sidestep rivals and claim the prize of fly-by seductions.