A taxonomic revision of South American species of the seed-harvester ant genus Pogonomyrmex (Hymenoptera: Formicidae). Part II

This paper provides a taxonomic revision and reviews natural history for 35 South American species of the seed-harvesting ant genus Pogonomyrmex. Species treated herein mostly comprise the P. rastratus-group; four species are revived from synonomy, three taxa are elevated from subspecies to species, five taxa are synonymized, and 20 new species are described. The following taxa are revived from synonomy: P. intermedia Menozzi, P. semistriata Emery, P. spinolae Emery, and P. weiseri Santschi. The following taxa are raised from subspecies to species: P. leonis Kusnezov, P. pulchellus Santschi, and P. sanmartini Kusnezov. The following new synonymies are proposed, with the senior synonym listed first, and the junior synonym(s) in parentheses: P. carbonarius Mayr (= P. kusnezovi Cuezzo & Claver, = P. weiseri var. neuquensis Santschi, = P. variabilis Santschi); P. vermiculatus Emery (= P. vermiculatus var. chubutensis Forel, = P. vermiculatus var. jorgenseni Forel). The following new species are described: P. apterogenos, P. araucania, P. atacama, P. bolivianus, P. colca, P. cusquena, P. excelsior, P. forelii, P. granulatus, P. lagunabravensis, P. loaensis, P. mapuche, P. maulensis, P. pichachen, P. propinqua, P. santschii, P. strioligaster, P. tafi, P. varicolor, and P. wilsoni. One species treated herein has brachypterous queens (P. atacama), one species has dimorphic queens (winged and brachypterous in P. longibarbis), and two species have ergatoid (permanently wingless) queens and ergatoid males (P. apterogenos, P. laguanbravensis); the latter two are the only known ant species in which both sexual castes are only ergatoid. I also provide keys for workers and queens (in English and Spanish), diagnoses for males, photographs of known castes, distribution maps, and a summary of known biology.

Cryptic Lineages in the Cardiocondyla sl. kagutsuchi Terayama (Hymenoptera: Formicidae) Discovered by Phylogenetic and Morphological Approaches

The taxonomy of ant species in the genus Cardiocondyla is very confused due to the extreme difficulty in separating many species based on morphology alone. In Japan, one group of the species complex Cardiocondyla sl. kagutsuchi has both winged and wingless worker-like (ergatoid) males (dimorphic) whereas others have only ergatoid males (monomorphic). The presence of both groups prompted us to hypothesize that C. sl. kagutsuchi presumably includes several independent species with differences in their male wing morphologies. However, whether any species boundary actually exists between the male groups has remained unsolved over the 10+ years since the previous revision of this genus. In this study, using discriminant and phylogenetic analyses, we compared the worker caste morphology of this species complex among lineages detected by phylogenetic analyses. In addition, we examined the number of sexuals present in field colonies. Our results revealed the existence of at least three morphological and phylogenetic groups within this species complex.