Key to Cylindromyrmex queens

This worker key is based on: De Andrade, M. L. 1998a. Fossil and extant species of Cylindromyrmex (Hymenoptera: Formicidae). Revue Suisse de Zoologie. 105:581-664.

The gyne of the Cylindromyrmex escobari is not included in this key because it was not known when this key was published.

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1

• First gastric tergite smooth . . . . . 2

• First gastric tergite sculpture . . . . . 5

2

return to couplet #1

• Postpetiole smooth or with very thing, short, superficial striae on the posterior half. Frontal carinae very broad, reaching the internal border of the eyes. Mandibles not angulate basally, convex dorsally and with 10-12 denticles. Colombia, Venezuela, Peru and Bolivia . . . . . Cylindromyrmex boliviae

• Postpetiole entirely striate. Frontal carinae not reaching the internal border of the eyes. Mandibles angulate basally, slightly convex or flat dorsally, with maximum 7 denticles . . . . . 3

3

return to couplet #2

• Legs dark yellow-orange to light brown. Body striation more irregular. Brazil, Paraguay . . . . . Cylindromyrmex brasiliensis

• Legs dark ferrugineous to black with large part of the tibiae yellowish. Body striation regular . . . . . 4

4

return to couplet #3

• Cephalic Index (CI) ≥ 80. Posterior third of the head dorsum at most with 25 striae. Guatemala, Costa Rica, Galapagos Island, Ecuador, Peru, Bolivia, Chile, Brazil . . . . . Cylindromyrmex whymperi

• Cephalic Index (CI) ≤ 77. Posterior third of the head dorsum with more than 34 striae. Surinam, French Guyana, Brazil . . . . . Cylindromyrmex striatus

5

return to couplet #1

• Frons at most slightly more than 1/3 the head width. Eyes on the middle of the head sides . . . . . 6

• Frons at least slightly less than ½ or more than ½ of the head. Eyes behind the middle of the head sides. . . . . . 8

6

return to couplet #5

• Frontal carinae not reaching the anterior clypeal border. Pygidium apically without a distinct pair of large teeth. Distal border of hind basitarsi with 5 spine-like setae . . . . . Cylindromyrmex longiceps

• Frontal carinae reaching the anterior clypeal border. Pygidium apically with a distinct pair of large teeth. Distal border of hind basitarsi with 3 spine-like setae . . . . . 7

7

return to couplet #6

• Outer apical edge of the mid basitarsi with 3 spine-like setae on the outer face. Cephalic Index (CI) ≤ 70. HFeI ≥ 50. Costa Rica, Panama, Venezuela, Brazil . . . . . Cylindromyrmex meinerti

• Outer apical edge of mid basitarsi with 5 spine-like setae on the outer face. Cephalic Index (CI) > 77. HFeI < 46. Domincan amber . . . . . Cylindromyrmex antillanus

8

return to couplet #5

• Head and mesosoma covered by thick and thin striae. Pygidium apically with a distinct pair of large teeth separated by a deep notch. Size large ≥ 12.5 mm. Cephalic Index (CI) < 71. Costa Rica, Panama, Ecuador . . . . . Cylindromyrmex godmani

• Head and mesosoma covered by uniform thin striae. Pygidium apically with 4-6 large teeth not separated by a notch. Size small < 9.5 mm. Cephalic Index (CI) > 78 . . . . . 9

9

return to couplet #8

• Coxae and femora black. Mid basitarsi with parallel sides and more than half longer than the hind basitarsi. Dominican amber . . . . . Cylindromyrmex electrinus

• Coxae, femora dark brown. Mid basitarsi broad apically and half as long as the hind basitarsi . . . . . 10

10

return to couplet #9

• Frontal carinae not surpassing the anterior clypeal border. Mandibles with 6-8 small denticles. Femora yeloowish to light brown. Venezuela, Ecuador, Peru and Brazil . . . . . Cylindromyrmex brevitarsus

• Frontal carinae surpassing the anterior clypeal border. Mandibles with 9-10 small denticles. Femora dark brown. Cuba . . . . . Cylindromyrmex darlingtoni