Key to Pheidole punctatissima group

This worker key is based on: Wilson, E. O. 2003. Pheidole in the New World: A dominant, hyperdiverse ant genus. Harvard University Press, Cambridge, MA.

This is a congeries of small, slender species with abundant cephalic sculpturing, relatively long antennal scapes, and typically large-eyed minors, that range from southern Mexico to northern and central South America. The greatest species diversity is in Central America. The affinities of the punctatissima group cannot be readily determined with existing evidence. It appears to fall roughly between the diligens, fallax, and flavens groups.

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• Pheidole
• "New World Pheidole" Wilson 2003

1

• Occipital lobes rugoreticulate . . . . . 2

• Occipital lobes among species variously rugose, carinulate, foveolate, and smooth and shiny but not rugoreticulate . . . . . 3

2

return to couplet #1

• Major: propodeal spine reduced to a right angle; scape reaches occipital corner; ocellus present; brown (montane Peru) . . . . . Pheidole inca

• Major: propodeal spine well developed, in side view half as long as the basal face of the propodeum anterior to it; scape failing to reach the occipital comer by 2 X its own maximum width; ocellus lacking; yellow (Veracruz, Mexico) . . . . . Pheidole tuxtlasana

3

return to couplet #1

• Major: in side view, no trace of mesonotal convexities present; instead, the promesonotal profile forms a smooth curve all the way back to the metanotal groove or else drops to it abruptly through a posterior face . . . . . 4

• Major: in side view, a mesonotal convexity is present, even though reduced in some species to a slight rise above the level of the pronotal profile . . . . . 6

4

return to couplet #3

• Major: in side view, promesonotal profile forms a continuous smooth curve all the way to the metanotal groove (Costa Rica) (placed in the flavens; also keyed out here to ensure identification) . . . . . Pheidole onyx

Pheidole onyx, Major

Minor

• Major: in side view, promesonotal profile drops abruptly through a distinct posterior face to the metanotal groove . . . . . 5

5

return to couplet #4

• Major: in side view, the propodeal spine is "melted"- blunt at the tip and curved backward; first gastral tergite smooth and shiny (Costa Rica) (placed in the flavens; also keyed out here to ensure identification) . . . . . Pheidole citrina

Pheidole citrina, Major

Minor

• Major: in side view, the propodeal spine is sharp and straight; median half of first gastral tergite shagreened and opaque (Costa Rica) . . . . . Pheidole gradifer

6

return to couplet #3

• Major: in full-face view, head strongly heart-shaped, and yellow with a circular brown spot on the vertex; when tips of scapes are touched to the margin of the head in full face, they fail to reach halfway between the horizontal levels of the posterior margin of the eye and of the occipital lobes (Costa Rica) (placed in the flavens; also keyed out here to ensure identification) . . . . . Pheidole daphne

Pheidole daphne, Major

Minor

• Major: in full-face view, head usually not heart-shaped, and never yellow with a brown spot on the vertex; tips of scapes reaching the midpoint between horizontal levels of eye and occipital lobes or beyond . . . . . 7

7

return to couplet #6

• Major: propodeal spine in side view reduced to a minute denticle or right angle formed by the juncture of the basal and descending faces of the propodeum . . . . . 8

• Major: propodeal spine in side view well developed . . . . . 9

8

return to couplet #7

• Major: occiput and pronotum smooth and shiny (tropical South America) (placed in the diligens group; also keyed out here to ensure identification) . . . . . Pheidole cataractae

Pheidole cataractae, Major

Minor

• Major: pronotum foveolate, occiput seen in full face longitudinally carinulate as well as foveolate, and both opaque (Costa Rica to Brazil and Peru) . . . . . Pheidole rugiceps (in part - also #18)

Pheidole rugiceps, Major

Minor

9

return to couplet #7

• Major: pronotum and occiput smooth and shiny (Costa Rica) . . . . . Pheidole humida (= Pheidole boltoni)

Pheidole boltoni, Major

Minor

• Major: pronotum foveolate, and occiput in full-face view either longitudinally carinulate, foveolate, or both; pronotum and occiput also opaque . . . . . 10

10

return to couplet #9

• Major: seen in dorsal-oblique view (mesosoma rotated around long axis 45 degrees from top view), the pronotal humerus is raised into a prominent cornicle; head strikingly bicolored, with anterior third brown and posterior two-thirds pale yellow (Mexico to Colombia) . . . . . Pheidole punctatissima

Pheidole punctatissima, Major

Minor

• Major: seen in dorsal-oblique view, the pronotal humerus evenly convex to sub angular and not raised as a discrete cornicle; head concolorous, either yellow or brown, or bicolorous, with anterior third yellow . . . . . 11

11

return to couplet #10

• In side view, propodeal spines as long as the basal face of the propodeum anterior to them (Colombia) . . . . . Pheidole cataphracta

Pheidole cataphracta, Major

Minor

• In side view pronotal spines at most half as long as the basal face of the propodeum anterior to them . . . . . 12

12

return to couplet #11

• Major: carinulae or rugoreticulum immediately mesad to eye not extending past the horizontal level of the posterior eye margin by more than the length of the eye . . . . . 13

• Major: carinulae or rugoreticulum immediately mesad to the eye extending half or more of the way from the horizontal level of the posterior eye margin to the occiput . . . . . 15

13

return to couplet #12

• Major: almost all of anterior half of head, including clypeus, rugoreticulate (Tamaulipas, Mexico) (placed in the fallax group; also keyed out here to ensure identification) . . . . . Pheidole nubicola

• Major: anterior half of head lacking rugoreticulum . . . . . 14

14

return to couplet #13

• Major: seen in profile, pilosity of first gastral tergite consisting of dense, subappressed hairs less than half as long as the length of the eye. Minor: head rectangular in shape, elongate (Head Length 1.30 X Head Width), and lacking a nuchal collar; clavate hairs not present on occiput and mesosomal dorsum; central strip of first gastral tergite entirely foveolate and opaque (Costa Rica) . . . . . Pheidole angusticeps

Pheidole angusticeps, Major

Minor

• Major: seen in profile, pilosity of first gastral tergite consisting of scattered sub erect hairs longer than the eye. Minor: head not elongate (Head Length only 1.14 X Head Width), and narrowed behind with a nuchal collar; a few clavate hairs present along with the usual, non-clavate pilosity on the occiput and mesosomal dorsum; first gastral tergite entirely smooth and shiny (Guyana to Brazil and Peru) . . . . . Pheidole meinerti

Pheidole meinerti, Major

15

return to couplet #12

• Major: entire body densely pilose, and in particular profiles of dorsum of mesosoma (thorax plus propodeum) and of head each with 30 or more hairs; pronotum bearing parallel transverse carinulae or rugoreticulum. Minor: nuchal collar present (Panama) . . . . . Pheidole dasypyx

Pheidole dasypyx, Major

Minor

• Major: body only sparsely to moderately pilose, with fewer than 20 hairs each on the mesosomal and cephalic profiles; pronotum lacking transverse carinulae. Minor: nuchal collar absent . . . . . 16

16

return to couplet #15

• Major: frontal lobes and pronotal dorsum rugoreticulate (Tamaulipas, Mexico) (placed in the fallax group; also keyed out here to ensure identification) . . . . . Pheidole nubicola

• Major: frontal lobes and pronotal dorsum carinulate or foveolate, not rugoreticulate . . . . . 17

17

return to couplet #16

• Major: in side view, outline of pro no tum forming a double convexity; profile of dorsum of head in side view “dented”-with a shallow concavity just anterior to occiput; a thin anterior portion of the central half of the first gastral tergite shagreened and opaque. Minor: pronotum in profile with a slight double convexity (Trinidad) . . . . . Pheidole aripoensis

Pheidole aripoensis, Major

Minor

• Major: in side view, outline of pro no tum composing a single convexity; profile of dorsum of head not “dented” anterior to occiput; first gastral tergite entirely smooth and shiny. Minor: pronotal profile composing a single convexity . . . . . 18

18

return to couplet #17

• Major: dorsum of head, from clypeus to occiput, completely covered by well demarcated parallel longitudinal carinulae; propodeal spine small, in side view only about as long as width of the propodeal spiracle. Minor: propodeal spine a triangular denticle only about as long as width of propodeal spiracle (Costa Rica to Brazil and Peru) . . . . . Pheidole rugiceps (in part - also #8)

Pheidole rugiceps, Major

Minor

• Major: longitudinal carinulae on dorsum of head posterior to eye broken into fragments and indistinct; propodeal spine twice as long in side view as width of the spiracle. Minor: propodeal spine well developed, longer than width of propodeal spiracle (Meta, Colombia) . . . . . Pheidole metana