Prenolepis

LaPolla, J. S., Brady, S. G. & Shattuck, S. O., 2010, Phylogeny and taxonomy of the Prenolepis genus-group of ants (Hymenoptera: Formicidae)., Systematic Entomology 35, pp. 118-131 : 123-124

Key to workers of the Prenolepis genus-group

This key can be modified to supplement many existing formicine keys such as Bolton (1994), Shattuck (1999) and Imai et al. (2003). In those keys, specimens that key to Paratrechina should be compared with couplets 3, 4 and 5 below to determine current generic placement. The relative eye length index (REL) is defined as (EL/HL) ×100, where HL (head length) is the length of the head, excluding the mandibles, measured in full-face view, and EL (eye length) is the maximum length of the compound eye in full-face view.

1. Maxillary palps with 5 or fewer segments; species often strongly polymorphic, with a major and minor caste expressed ........................................... 2

- Maxillary palps with 6 segments; species monomorphic to slightly polymorphic, with no discernable major or minor caste expressed ..................................... 4

2. Polymorphic Afrotropical species ..... Paraparatrechina bufonus and weissi

- Monomorphic or polymorphic Australasian/Indoaustralian species ............................................. 3

3. Eyes large, typically REL 20 or greater (one exception - E. negrosensis ); labial palps typically with 4 segments; mesothorax constricted immediately behind pronotum; mandalus large and conspicuous (Fig. 7A), usually visible without dissection of mandible*.... Euprenolepis

- Eyes small, REL less than 20, typically 15 or less; labial palps typically with 2 or 3 segments; mesothorax typically not constricted immediately behind pronotum; mandalus small and inconspicuous (Fig. 7F), usually not visible without dissection of mandible* ........... Pseudolasius

4. Mandibles typically with 6 to 7 teeth, rarely 5 teeth present; if with 5 teeth, then mesothorax constricted immediately behind pronotum; scapes with or without erect setae... 5

- Mandibles always with 5 teeth; mesothorax not constricted immediately behind pronotum; scapes always lacking erect setae ............................................... 6

5. Mesothorax constricted immediately behind pronotum; eyes largely above midlength of head (typically posterior of vertex); mandibles with distinct striations across anterior surface .................................... Prenolepis

- Mesothorax not constricted immediately behind pronotum; eyes with about half their length above and half their length below midlength of head (typically at vertex); mandibles without strations across anterior surface ..... Nylanderia

6. Erect setae (one pair) present on propodeum; erect setae on head form a pattern of 4 setae along posterior margin and 6 to 7 rows of setae from posterior margin to clypeal margin; dorsal face of propodeum typically short and angular; femora and tibiae lacking large erect setae ................................ Paraparatrechina

- Erect setae absent on propodeum; erect setae on head scattered across surface; dorsal face of propodeum broad and gently rounded; femora and tibiae with large erect setae .................................... Paratrechina