Key to species of Cochliomyia of the West Indies

1. Genal dilation antero-dorsally with few to many short, black setae (Fig. 21); T5 cupreous, contrasting in color with preceding tergites (Fig. 22); mesonotum with 3 broad black polished vittae alternating with narrower, gray microtomentose vittae (Fig. 5); postgenal setulae white........................................................................................................ 2

- Genal dilation with entirely yellow setae; T5 blue to green, concolorous with preceding tergites; mesonotum with three black polished vittae alternating with about equal width green or blue microtomentose vittae; postgenal setulae yellow........................................................................................................................................................................... 3

2. T5 with pair of median dorsal silvery microtomentose spots (Fig. 22); occiput with few to numerous dark setae in upper part, just below postocular setae; frons of male narrower, 0.06 (0.05–0.065/8) head width, equal to or narrower than the width of first flagellomere; surstylus and cercus long and slender (Figs. 31, 33) ........................... C . aldrichi

- T5 with uniform dusting of microtomentum; occiput with pale setae only below postocular setae; frons of male broader, 0.083 (0.075–0.09/2) head width, width broader than width of first flagellomere; surstylus digitate, cercus with broad base tapering sharply to point (Figs. 32, 34) ............................................................................... C . minima

3. Fronto-orbital plate with dark setulae outside row of frontal setae (Whitworth 2006, fig. 53, right side); T5 without pronounced silvery microtomentum; postgenal setae usually golden yellow; female with dark basicosta; proclinate orbital setae absent; not found in North America since 1966 due to eradication efforts; found in parts of Mexico, Central and South America, possibly in isolated areas in the West Indies ............................................ C . hominivorax

- Lower third to half of fronto-orbital plate with pale setulae outside row of frontal setae (Whitworth 2006, fig. 53, left side); T5 usually with pronounced silvery microtomentum laterally; postgenal setae usually pale yellow; female usually with yellowish basicosta; usually with two pairs of proclinate orbital setae (sometimes only one on one or both sides). Widespread in Neotropical and Nearctic Regions ......................................................................... C . macellaria