Key to Trinodia species

This key to the species of Trinodia is based on: [[Media:Potts 1945 key to species cremastocheilini.pdf|Potts, R.W.L. 1945. A key to the species of Cremastocheilini of North American and Mexico (Coleoptera: Scarabaeidae). Bull. Brooklyn Ent. Soc. 40: 72-78.]] and Alpert, Gary D. 1994. A Comparative Study of the Symbiotic Relationship Between Beetles of the Genus Cremastocheilus (Coleoptera: Scarabaeidae) and their Host Ants (Hymenoptera:Formicidae). Sociobiology 25(1).

You may also be interested in: [[Media:Krikken 1981.pdf|Krikken, J. 1982. North American myrmecophilous beetles of the genus Cremastocheilus: discussion of their classification and a review of the subgenera Trinodia and Anatrinodia (Coleoptera: Cetoniidae). Proceedings of the Koninklijke Nederlandse Academie van Wetenschappen. Series C. p. 509-526.]] and [[Media:Mynhardt & Wenzel 2010.pdf|Mynhardt, G. & J.W. Wenzel 2010. Phylogentic analysis of the myrmecophilous Cremastocheilus Knoch (Coleoptera, Scarabaeidae, Cetoniinae), based on external adult morphology. ZooKeys 34: 129-140.]]

1

 * Front of head with a transverse impression in front of eyes; Pronotum only slightly more than one-half as wide as elytra (Fig. ) ..........Cremastocheilus constricticollis


 * Front of head without a transverse impression in front of eyes; Pronotum at least three-fourths as wide as elytra . . . . . 2

2
return to couplet #1
 * Tarsi 4-segmented, AZ (Fig. ). . . . . Cremastocheilus lengi


 * Tarsi 5-segmented . ... . . . . . 3

3

 * Large tuft of trichome hairs on ocular canthus and in depression centrad of anterior pronotal angles (Fig. ) ...Cremastocheilus opaculus


 * No tuft of trichome hairs on ocular canthus and no trichome hairs or a depression centrad of anterior pronotal angles ..... . . . . . 4

4

 * Posterior tibia notably broad and laterally compressed......... . . . . . 5


 * Posterior tibia not notably broad and laterally compressed..... . . . . . 6