Palpada ruficeps

Mengual, Ximo & Thompson, Christian, 2008, A taxonomic review of the Palpada ruficeps species group, with the description of a new flower fly from Colombia (Diptera: Syrphidae), Zootaxa 1741, pp. 31-36 : 34-35

Key to the species of the Palpada ruficeps subgroup

1. Katepimeron bare; wing partially microtrichose, with at least some microtrichia on apical wing cells....... ................................................................................................................................... other Palpada species

- Katepimeron pilose; wing completely bare or almost, with only a few microtrichia medially, always bare apically.........................................................................................................................................................2

2. Posterior anepimeron bare; metatibia always transverse apically, without dens, usually not ciliate; small flies, about 12 mm or less.......................................................................................... other Palpada species

- Posterior anepimeron pilose; metatibia with apicolateral dens (tooth), ciliate; large flies, usually about 18 mm ( ruficeps subgroup)...............................................................................................................................3

3. Scutellum black, black pilose. Metatarsus pale orange; abdomen black except for large quadrate yellow macula on 2nd tergum ( Costa Rica to Peru) ........................................................................ bistellata (Hull)

- Scutellum pale, yellow to red or orange, pale pilose...................................................................................4

4. Metatarsus pale, orange to red. 2nd thru 4th terga red except for narrow basomedial black vitta ( Ecuador) ..................................................................................................................................... suprarufa Thompson

- Metatarsus dark, brown to black; abdomen more extensively dark, 2nd tergum dark with basolateral pale yellow to orange or brownish-orange maculae; 3rd and 4th terga usually entirely dark.............................5

5. Pleuron entirely yellow to orange pilose; calypter orange; postalar callus orange pilose; wing entirely hyaline ( Colombia to Bolivia) ............................................................................................. ruficeps (Macquart)

- Pleuron entirely black pilose; calypter brownish black on basal 1/2; postalar callus black pilose; wing blackish on anterobasal 2/3 ( Colombia) ....................................................... prietorum Mengual spec. nov.