The ants of the genus Rhopalothrix Mayr, 1870 (Hymenoptera, Formicidae, Myrmicinae) in Colombia.

The ants of the genus Rhopalothrix are diverse in the Neotropical region, with 14 of the 16 described species. Based on museum material and recent fieldwork, Rhopalothrix ants in Colombia were reviewed. Morphological analysis of the workers allowed delimitation of six species, including two new species, Rhopalothrixmandibularis Guerrero & Grajales, sp. nov. and Rhopalothrixmariaemirae Tocora, Fiorentino & Fernández, sp. nov. A new combination Rhopalothrixamaticomb. nov. is proposed for Eurhopalothrixamati. A worker-based taxonomic key, high-definition images of the workers, and a distribution map of all Rhopalothrix species present in Colombia are provided.

The Pheidole Westwood, 1839 ants (Formicidae: Myrmicinae) in Colombia: new records including two species with remarkable morphology.

Pheidole is one of the most diverse groups of ants in the World, with more than 630 species known from the Neotropical Region. As part of studies on the ant fauna of Colombia, a contribution to the taxonomy of these ants is presented here. The worker subcastes of Pheidole praeusta Roger are redescribed, this being the first record of a trimorphic species outside the Nearctic region. Pheidole amata Forel is proposed as a junior synonym of Pheidole praeusta. Pheidole rogeripolita Longino is identified as the first species in the New World with a 5-segmented antennal club, and the third species with such antennal club in the world. Pheidole distorta Forel, a species described 120 years ago, is redescribed, and notes on its reproductive caste are offered. The description and diagnosis of the Pheidole iceni Fernndez soldier is amended. New species records for the country and South America are listed. Multifocus photographs of P. praeusta, and P. rogeripolita are offered.

Morphological and genetic evidence supports the separation of two Tapinoma ants (Formicidae, Dolichoderinae) from the Atlantic Forest biome.

The taxonomic boundaries of many Neotropical ant species of the genus Tapinoma are still unclear. Tapinoma atriceps and T. atriceps breviscapum are two morphologically similar taxa which occur sympatrically in the southern Atlantic Forest of Brazil. Some characters such as the scape length and head shape suggest that these taxa may be different species. We used DNA analysis and morphological evidence, including scanning electron microscopy, to evaluate the taxonomic validity of these taxa. We found distinct morphological characteristics that allow separating them as two different species, Tapinoma atriceps and Tapinoma breviscapum status novo, and this decision is supported by the DNA results, where Tapinoma atriceps was recovered as a lineage independent of T. breviscapum.

Transfer of two South American ant species from Tapinoma Foerster 1850 to Forelius Emery 1888 (Hymenoptera: Formicidae: Dolichoderinae).

Some species of the ant genus Forelius can be misclassified as the genus Tapinoma due to the convergent reduction of the petiolar scale. I review the taxonomic status of Tapinoma antarcticum Forel 1904 and Tapinoma heyeri Forel 1902. Morphological evidence supports the transfer of these names to the ant genus Forelius. Proposed taxonomic changes are as follows: Forelius antarcticus (Forel) comb. nov. (=Forelius fazi (Santschi 1923) comb. nov., =Forelius eidmanni Goetsch 1933 comb. rev.); Forelius heyeri (Forel) comb. nov. (=Forelius heyeri risii (Forel 1912) comb. and syn. nov., =Forelius pusillus (Santschi 1922) syn. nov., =Forelius tucumanus (Kusnezov 1953) syn. nov.). Lectotypes for Forelius antarcticus and Forelius heyeri are designated. The worker of Forelius heyeri, as well as the worker and queen of Forelius antarcticus are diagnosed and redescribed. Multifocus images for lectotype workers are provided. Morphological variation within and between species of Forelius with rounded spiracles is discussed.

Schismatothelinae spiders (Araneae, Mygalomorphae, Theraphosidae) from Colombia: four new species and an approach to their diversity.

The spider subfamily Schismatothelinae from Colombia is revised. One new species of Euthycaelus Simon 1889 and three new species of Schismatothele Karsch 1879 are named, as well as new geographical records provided. E. guane sp. nov. from Santander, S. hacaritama sp. nov. from Norte de Santander, S. olsoni sp. nov. from Norte de Santander and Táchira (Venezuela), and S. weinmanni sp. nov. from Cundinamarca are herein described, diagnosed and illustrated. Schismatothele is newly recorded from Colombia. Morphological aspects and diversity of the Ischnocolinae and Schismatothelinae from Colombia are discussed. An identification key to species of these subfamilies from Colombia is provided.

Taxonomic identity of the ghost ant, Tapinoma melanocephalum (Fabricius, 1793) (Formicidae: Dolichoderinae).

This paper revises the taxonomy of Tapinoma melanocephalum (Fabricius, 1793) as follows: T. melanocephalum = Tapinoma luffae (Kuriam, 1955) syn. nov., = Tapinoma melanocephalum coronatum Forel, 1908 syn. nov., = Tapinoma melanocephalum malesianum Forel, 1913 syn. nov. A neotype of Tapinoma melanocephalum (Fabricius, 1793) is designed here. Lectotypes of Tapinoma melanocephalum coronatum Forel, 1908 and T. melanocephalum malesianum Forel, 1913 are designated. Formica wallacei is proposed as a replacement name for Formica familiaris (= T. melanocephalum senior synonym). The worker, queen and male are redescribed and diagnosed. The morphological variability of populations is discussed. All castes are included in full color images.

The ant genus Linepithema (Formicidae: Dolichoderinae) in Colombia.

The species of Linepithema Mayr in Colombia are reviewed from collection material. The genus Linepithema comprises 20 species, of which the following are reported in Colombia: L. angulatum (Emery), L. dispertitum (Forel), L. gallardoi (Brèthes), L. humile (Mayr), L. iniquum (Mayr), L. neotropicum Wild, L. piliferum (Mayr), L. tsachila Wild, and a new species, Linepithema hirsutum sp. nov. Linepithema dispertitum is a new record for Colombia and South America. A taxonomic key (English and Spanish) and distribution maps to the species of Linepithema in Colombia are provided.

A temporary social parasite of tropical plant-ants improves the fitness of a myrmecophyte.

Myrmecophytes offer plant-ants a nesting place in exchange for protection from their enemies, particularly defoliators. These obligate ant-plant mutualisms are common model systems for studying factors that allow horizontally transmitted mutualisms to persist since parasites of ant-myrmecophyte mutualisms exploit the rewards provided by host plants whilst providing no protection in return. In pioneer formations in French Guiana, Azteca alfari and Azteca ovaticeps are known to be mutualists of myrmecophytic Cecropia (Cecropia ants). Here, we show that Azteca andreae, whose colonies build carton nests on myrmecophytic Cecropia, is not a parasite of Azteca-Cecropia mutualisms nor is it a temporary social parasite of A. alfari; it is, however, a temporary social parasite of A. ovaticeps. Contrarily to the two mutualistic Azteca species that are only occasional predators feeding mostly on hemipteran honeydew and food bodies provided by the host trees, A. andreae workers, which also attend hemipterans, do not exploit the food bodies. Rather, they employ an effective hunting technique where the leaf margins are fringed with ambushing workers, waiting for insects to alight. As a result, the host trees' fitness is not affected as A. andreae colonies protect their foliage better than do mutualistic Azteca species resulting in greater fruit production. Yet, contrarily to mutualistic Azteca, when host tree development does not keep pace with colony growth, A. andreae workers forage on surrounding plants; the colonies can even move to a non-Cecropia tree.