Key to Stigmatomma of the New World (Outdated)

This worker and queen key is based on Lattke, J. E. 1991. Studies of neotropical Amblyopone Erichson (Hymenoptera: Formicidae). Contributions in Science (Los Angeles). 428:1-7.

The key is outdated. For a more recent key: Stigmatomma species of the Americas

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 * Stigmatomma
 * Key to Stigmatomma of the United States

1

 * Antenna with 12 segments . . . . . 3


 * Antenna with < 12 segments . . . . . 2

2
return to couplet #1
 * Antenna with 11 segments; HW > 0.70, WL > 1.10 mm (Puerto Rico, Hispaniola, Saint Thomas) . . . . . Stigmatomma falcatum


 * Antenna with 6 or 7 segments; HW < 0.70, WL < 1.10 mm (SE Brazil, SE Peru) . . . . . Stigmatomma degeneratum

3
return to couplet #1
 * Lobes of frontal carinae separated by a distinct gap . . . . . 4


 * Lobes of frontal carinae contiguous or fused . . . . . 7

4
return to couplet #3
 * Mandibles on inner surfaces each with 2 separate rows of small, sharp sparse teeth (c. America-SE Colombia) . . . . . Stigmatomma mystriops


 * Mandibles on inner surfaces with much larger teeth, those near midlength fused at bases to form heavy double teeth . . . . . 5

5
return to couplet #4
 * Inner borders of mandible angularly produced, so that the blades are triangular in shape without the apices; large double teeth with rounded apices; genal teeth reduced to inconspicuous obtuse angles (N. Carolina, U.S.A.) . . . . . Stigmatomma trigonignathum


 * Inner borders of mandibles straight to convex, not angularly produced, the blades linear; large double teeth prominently acute; genal teeth acute and projecting . . . . . 6

6
return to couplet #5
 * Inner borders of mandibles and anterior clypeal margin straight (N California to British Columbia) . . . . . Stigmatomma oregonense


 * Inner borders of mandibles, and usually also the anterior clypeal margin convex in outline (temperate N. America at least to Arizona) . . . . . Stigmatomma pallipes

7
return to couplet #3
 * At least the anterior 3/5 of the head (full-face view) predominantly densely sculptured and opaque . . . . . 8


 * Entire or nearly entire cephalic dorsum smooth and shining, with spaced punctures . . . . . 12

8
return to couplet #7
 * Anterior 1/3-3/4 of cephalic dorsum longitudinally striate with intermixed punctures and/or posterolateral propodeal corners each with testaceous to ferrugineous yellow spot; color of body mostly black or brown . . . . . 9


 * Cephalic dorsum densely and uniformly punctate or striolate-punctate (except for shining border of median frontal groove in some cases); longitudinal striae on anterior 1/3-3/4 of head absent; yellowish posterolateral propodeal spots always absent; color of body mostly yellow or ferruginous . . . . . 10

9
return to couplet #8
 * Longitudinal striae on anterior 1/2-3/4 of cephalic dorsum well developed; sculpture on remainder of cephalic dorsum consisting of distinct punctures only, with spaces between them smooth and shining; propodeum completely black (SE Brazil-N Argentina) . . . . . Stigmatomma armigerum


 * Longitudinal striae usually confined to anterior 1/4-1/3 of head, sometimes weakly extending further toward vertex, sometimes very feebly developed and difficult to see; sculpture on remainder of cephalic dorsum consisting of moderately dense punctures, the spaces between them, if present, shining; propodeum with a testaceous to ferrugineous yellow spot on each of its posterolateral corners (N South America, SE Peru, N Argentina) . . . . . Stigmatomma lurilabes

10
return to couplet #8
 * Mesosoma smooth, punctation sparse; propodeum with very few punctures on dorsum, and its lateral striation restricted to the lower third; color yellow (Mexico-Choco, Colombia) . . . . . Stigmatomma orizabanum


 * Punctures more abundant and distinct on meso soma; sculpture of propodeal lateral faces covers one-half or more of surfaces . . . . . 11

11
return to couplet #10
 * Unique holotype worker 4.5 mm long (according to original description) (Cuba) . . . . . Stigmatomma bierigi


 * Worker TL 3.0-4.1 mm; female TL 4.1-4.5 mm (Chile) . . . . . Stigmatomma chilense

12
return to couplet #7
 * HW > 0.70 mm; straight anterior clypeal margin with small median tooth, not advanced beyond the larger lateral teeth (Chile) . . . . . Stigmatomma monrosi


 * HW < 0.70 mm; convex anterior clypeal margin with median tooth advanced beyond lateral teeth (SE Brazil-N Argentina) . . . . . Stigmatomma elongatum