Linepithema dispertitum

Escárraga, Mayron & Guerrero, Roberto J., 2016, The ant genus Linepithema (Formicidae: Dolichoderinae) in Colombia, Zootaxa 4208 (5), pp. 446-458 : 449-450

Linepithema dispertitum

( Figs. 2 A–2F, 4)

Distribution. Ramirez et al. (2001) reported L. dispertitum from a tropical dry forest in the eastern region of Colombia between the Western and Central Cordilleras, however Wild (2007) found this species only in Central America and Hispaniola. Further identification of Linepithema specimens from MUSENUV, the museum where the specimens are deposited, corroborated the absence of this species in that Colombian region. We report L. dispertitum for the first time in Northern Colombia and South America, from ants collected in the departments of Cesar and La Guajira. The collection sites were three nearby localities in the Serranía del Perijá over 2790 m (ranging from 2790 to 2997 m) bordering with Venezuela ( Fig. 4 ).

Biology. Linepithema dispertitum was found in high altitudes, in accordance with the reports in Wild (2007). Specimens were collected with pitfall traps and manually in a paramo landscape, where the annual precipitation is 1300–1400 mm, and the average temperature between 10–12°C ( Hijmans et al. 2004a). Workers were walking on the soil and under rocks, where the species probably nests. This behavior contrasts with its sister species, L. iniquum , which is considered an arboreal ant.

Discussion. Wild (2007) mentions that L. dispertitum presents allopatric morphological variation, identifying four phenotypes along its distribution in Central and North America. We observed three different phenotypes occurring in different sites of the Serranía del Perijá. One is similar to populations from central México: yellowbrown ( Figs. 2 C, 2D), lacking erect setae on the cephalic dorsum, and pubescence fading to sparse on gastric tergites 3–4. A second variation is similar to populations from Chihuahua (Mexico): bicolored ( Figs. 2 A, 2B), with four erect setae on the cephalic dorsum, setae on the pronotum, and moderate pubescence on gastric tergites 3–4. The third variation is curiously similar to a single collection from Baja California: it is bigger (HW 0.75), dark and concolored ( Figs. 2 E, 2F), with 5 erect setae on the cephalic dorsum, and some sparse hairs on the mesopleura. In Colombia, populations with the same pattern of variability are sympatric, occurring relatively close each other in altitudes above 2500 m in the Serranía del Perijá ( Fig. 4 ) and in some cases cohabiting the same environment (Department of Cesar).

Examined material. CESAR: Serranía del Perijá, Manaure, Sabana Rubia, 2850–2903 m ; Serranía del Perijá, La Paz, San José de Oriente, 2493 m (CBUMAG) . LA GUAJIRA: La Jagua del Pilar, Cerro Pintao, 2790 m (CBUMAG).

Figures

FIGURE 2. Linepithema dispertitum workers. A – B: Colombia, Cesar, CBUMAG- 06576. C – D: Colombia, Guajira, CBUMAG- 06577. E – F: Colombia, Cesar, CBUMAG- 06575.

FIGURE 4. Linepithema gallardoi, L. neotropicum and L. iniquum distribution in Colombia from examined material.