Key to Temnothorax of California

A key to Temnothorax  workers of California. Based on Snelling, R.R., Borowiec, M.L. & Prebus, M.M. 2014. Studies on California ants: a review of the genus Temnothorax (Hymenoptera, Formicidae). ZooKeys 372:27–89. doi:10.3897/zookeys.372.6039

The following worker-based key includes the 20 species of Temnothorax known from California, plus two additional species (Temnothorax nuwuvi, Temnothorax carinatus) known from neighboring states to the east.

In California, Temnothorax can be most easily confused with Leptothorax, Tetramorium and Myrmica, but all these genera have at least six mandibular teeth. Additionally, Tetramorium and Myrmica possess mid- and hind tibial spurs. In western North America, workers of Temnothorax can be recognized by a combination of a waist consisting of two segments (petiole and postpetiole); postpetiole attached to anterior face of abdominal segment 4 (first gastral segment); absence of promesonotal suture from mesosoma; antennae 11- or 12-segmented and with differentiated 3-segmented club; eyes present and consisting of at least several facets; frontal carinae not laterally expanded or extending posteriorly past the eye; presence of median clypeal carina; clypeus elevated slightly above mandibles in profile view, not an anteriorly projecting lobe that fits tightly over the base of the mandibles; mandibles with five teeth; propodeal spines present at least as distinct tubercles and tibial spurs on middle and hind legs absent.

1

 * Antenna 11-segmented . . . . . 2
 * Antenna 12-segmented . . . . . 5