Linepithema

Escárraga, Mayron & Guerrero, Roberto J., 2016, The ant genus Linepithema (Formicidae: Dolichoderinae) in Colombia, Zootaxa 4208 (5), pp. 446-458 : 448

Key to the species of Linepithema in Colombia based on workers

1. Anterior portion of the metapleural gland orifice with moderate to abundant appressed hairs (sometimes individuals must be observed in dorsal-oblique position)...................................................................... 2

- Anterior portion of the metapleural gland orifice lacking pubescence, or with a few scattered appressed hairs............ 4

2. Pronotum with one pair of erect setae (may be lost); maxillary palps long, more than half of HL; metanotal groove slightly or not impressed; propodeum low and rounded.................................................... L. neotropicum

- Pronotum usually without erect setae, rarely with one pair; length of maxillary palps half or less than HL; metanotal groove slightly to moderately impressed; propodeum inclined anteriorly, with dorsal and posterior face forming an obtuse angle....3

3. Antennal scapes relatively short, usually less than HL; pronotum and first gastric tergite bearing setae (sometimes may be lost); mesonotum angular, with a posterior declivous face and sometimes swollen.......................... L. gallardoi

- Antennal scapes long, equal or longer than HL; pronotum and first gastric tergite without setae; mesonotum straight, not angular or swollen.................................................................................. L. humile

4. Posterior portion of clypeus with a weakly developed to absent groove (presutural clypeal groove).................... 5

- Presutural clypeal groove well-developed................................................................. 6

5. Dorsum of the head with more than 5 erect setae, mesosoma slender, dorsum of the mesonotum with a moderate to strong medial impression, body surface glossy and shiny.................................................... L. iniquum

- Dorsum of the head never with more than 5 erect setae, mesosoma more robust, medial impression on the mesonotum slightly impressed or not impressed at all, body not as glossy and shiny....................................... L. dispertitum

6. Pronotum bearing more than 10 erect setae, whole body surface with long or short erect setae................ L. hirsutum

- Pronotum with fewer than 10 erect setae, whole body surface never covered with erect setae......................... 7

7. Posterior margin of the head deeply concave, dorsum of mesonotum never with a medial impression, pronotum usually with 4 (2–8) erect to suberect setae..................................................................... L. tsachila

- Posterior margin of the head straight to slightly concave, dorsum of mesonotum without medial impression or slightly impressed, pronotum never with more than 4 erect setae.......................................................8

8. Antennal scapes short, surpassing the posterior margin of the head by less than length of the pedicel; propodeum relatively high, with distinct anterior, dorsal and posterior faces, sometimes dorsal face slightly depressed............. L. angulatum

- Antennal scapes relatively long, surpassing the posterior margin of the head by at least length of the pedicel; propodeum usually rounded, not as above...................................................................... L. piliferum