Key to Oceanian Proceratium Species

The following key is based on Baroni Urbani, C., de Andrade, M.L. (2003) The ant genus Proceratium in the extant and fossil record (Hymenoptera: Formicidae). Museo Regionale di Scienze Naturali, Monografie, 36, 1–492.

1

 * Petiole triangular and clearly narrowing dorsally in profile (Figs. 126, 127) . . . . . 2


 * Petiole rectangular, broad or narrow but never narrowing dorsally in profile (Figs. 131, 150) . . . . . 3

2
return to couplet #1
 * Lateral expansions of the frontal carinae broad and widely separated from each other. Head densely punctate (Fig. 126). SI > 76. TL > 4.5 mm. Fiji Islands . . . . . Proceratium relictum


 * Lateral expansions of the frontal carinae narrow and closer to each other. Head sparsely punctate (Fig. 127). SI < 73. TL < 3.7 mm. Fiji Islands . . . . . Proceratium oceanicum

3
return to couplet #1
 * TL ≤ 2.3 mm. Frontal carinae about 1/4 of the head width . . . . . 4


 * TL ≥ 2.37 mm; if the TL approaches 2.3 mm (in papuanum TL 2.37-2.59 mm), then the frontal carinae are 1/3 of the head width . . . . . 5

4
return to couplet #3
 * Head dorsum and mesosoma strongly reticulate. Mesosoma convex in profile. Colour dark reddish-brown. CI ≥ 100. Papua New Guinea . . . . . Proceratium snellingi


 * Head dorsum and mesosoma at most minutely punctate. Mesosoma elongate in profile. Colour black. CI < 96. Papua New Guinea . . . . . Proceratium ivimka

5
return to couplet #3
 * Frontal area very broad, at least 1/3 of the maximum head width . . . . . 6


 * Frontal area at most 1/4 of the maximum head width . . . . . 7

6
return to couplet #5
 * TL < 2.65 mm. Mesosoma, petiole and postpetiole with traces of granulation. Papua New Guinea, Philippines, Sumatra, Malaysia, Sabah and Solomon Islands . . . . . Proceratium papuanum


 * TL > 3.00 mm. Mesosoma, petiole and postpetiole at most minutely punctate. New Caledonia . . . . . Proceratium politum

7
return to couplet #5
 * Body smooth and at most with minute piligerous punctures. Petiolar width less than 1 and ½ of the petiolar length. Colour yellow-light brown, legs concolourous. New Caledonia . . . . . Proceratium caledonicum


 * Body superficially smooth and at least with punctations and small, sparse granulation. Petiolar width at least 1 and ½ of the petiolar length. Colour dark reddish brown or black with lighter legs. Papua New Guinea . . . . . Proceratium austronesicum