Federico A. Agrain

Description and phylogenetic relationships of two new species of Baripus (Coleoptera: Carabidae: Broscini) and considerations regarding patterns of speciation

ABSTRACT Baripus Dejean is a genus of the family Carabidae restricted to southern South America. Three subgenera are recognized within the genus; one of them, Cardiophthalmus Curtis, is endemic to the Patagonian Steppe. Together with the members of the genus Cnemalobus Guérin-Méneville, these beetles are the largest Carabidae of the Patagonian Steppe. New studies in the northern region of Patagonia, the Payunia, reveal the presence of two new species, Baripus (Cardiophthalmus) nevado, new species, and Baripus (Cardiophthalmus) precordillera, new species, restricted to isolated montane habitats. In this paper, we provide morphological descriptions of the new taxa with illustrations of male and female genitalia. We also conducted a phylogenetic analysis including all known species of Baripus. The cladistic analysis showed that B. (C.) mendozensis, B. (C.) nevado and B. (C.) precordillera constitutes a monophyletic group of species. These three species are allopatric, but B. (C.) mendozensis and B. (C.) nevado ranges are in close proximity. The distribution pattern, together with the phylogenetic pattern, suggests a possible peripatric pattern of speciation. We used a predictive model of species distribution to establish the present, past, and future distribution of B. (C.) mendozensis which is the most widely distributed species. Based on these analyses, we speculate that the current pattern of speciation may be a result of climatic changes during the Pleistocene.

Phylogenetic relationships and biogeographic considerations of four new species of Cnemalobus (Coleoptera: Carabidae) from Patagonia

Four new species of Cnemalobus Guerin-Meneville, 1838 (Carabidae) from the northern steppe of Patagonia and extra-Andean mountains are described in this work. Two of these species, Cnemalobus nevado sp. n. and Cnemalobus diamante sp. n., are from the Payunia (Argentina), the northernmost region of Patagonia. One species, C. somuncura sp. n., is from the vicinity of the Somuncura Plateau. The other species, Cnemalobus troll sp. n., is from the northwestern steppe. Illustrations and keys for these new species are provided. The phylogenetic relationships among the new species were defined using a cladistic analysis for the genus Cnemalobus, based on 56 characters of the external morphology and male and female genitalia. The cladogram showed that C. nevado sp. n. and C. diamante sp. n. comprise a monophyletic group that is the adelphotaxon of an apical clade of species that mainly inhabit mountain habitats in central Chile. Cnemalobus somuncura sp. n. and C. troll sp. n. are also sister species and comprise the apical group of the Patagonian species. Cnemalobus nevado and C. diamante occur in the Payunia, and their distribution is restricted to different mountains and are isolated from each other. Given that these two mountains are 200 km apart, it is not likely that dispersal has occurred in these large and flightless species. The ancestral species might have been broadly distributed, and, as a result of habitat changes, they became isolated into restricted habitats in the upper part of each mountain, where speciation might have occurred. The other two new species, C. somuncura and C. troll, are placed in the group of Patagonian species that inhabit the lowlands or plateaus. Distributional data, together with phylogeny, showed that the sister species of Cnemalobus have an allopatric distribution. Strict sympatry (same locality) occurs in the northwestern region of the Patagonian Steppe. Nevertheless, this strict sympatry may be an artifact of geographical scale. For example, within the same area, some species may inhabit grasslands next to forests, while other species inhabit only steppe areas.

Systematics and cladistics of Megalostomis Chevrolat, and the biogeography of Clytrini (Coleoptera: Cryptocephalinae)

We present a cladistic analysis of the subtribe Megalostomina, a Neotropical group of ‘case‐bearer’ leaf beetles. A comparative study of the external and internal adult morphology of Clytrini was undertaken. New characters are described for the subtribe Megalostomina, from the internal sac of aedeagus, which provide a useful phylogenetic signal. More than 180 photographs illustrating the most important characters (74 characters and their respective states) used in the cladistic analysis are provided. The cladistic analysis of 57 terminal taxa and 95 characters was undertaken, under equal weights, and also using implied weights as a means to down‐weight homoplasious characters. We test the monophyly and explore intergeneric relationships of the subtribe Megalostomina, and reconstruct the relationships among the species of Megalostomis Chevrolat. The 42 species recognized can be assigned either to a group mostly containing species of North and Central America, or to a larger one of mostly South American species. Support is low, and the formal naming of groups is deferred pending a revision of all Megalostomina. We confirm the subgenera of Megalostomis of previous classifications are unnatural, and the following changes in the generic classification of the subtribe Megalostomina are proposed: Coleorozena Moldenke syn.n. of Coscinoptera Lacordaire; Coleothorpa Moldenke syn.n. of Coscinoptera Lacordaire; and Euryscopa (Coleoguerina) Moldenke syn.n. of Coscinoptera Lacordaire. Furthermore, six formerly recognized subgenera of Megalostomis are considered junior synonyms of Megalostomis Chevrolat: Megalostomis (Minturnia) Lacordaire syn.n.; Megalostomis (Heterostomis) Lacordaire syn.n.; Megalostomis (Scaphigenia) Lacordaire syn.n.; Megalostomis (Snellingia) Moldenke syn.n.; Megalostomis (Coleobyersa) Moldenke syn.n.; and Megalostomis (Pygidiocarina) Moldenke syn.n. Thus, no subgenera are recognized within Megalostomis. Previous hypotheses on Clytrini biogeography were revisited in the light of new biogeographic and phylogenetic knowledge. We hypothesize an origin of Clytrini in tropical/subtropical Gondwana, when South America, Africa, Madagascar and India were connected. Changes in the configuration of the tectonic plates in the Cenozoic allowed the dispersal of Clytrina to the Palaearctic and Nearctic regions, and dispersion of Babiina and Megalostomina through the Nearctic region.

Vicariance events shaping Southern South American insect distributions

The main goal of this study is to use multiple insect phylogenies along with geographical information to test known vicariance hypotheses for Southern South America. We analysed the phylogenies and geographical distributions of seven insect genera endemic to southern South America using Hovenkamps ( ) protocol, which have been in part implemented in software (vicariance inference program). Using this software, we were able to hypothesize 55 traceable vicariance events; among these, we recognized four supported vicariance events (i.e. confirmed by more than a single sister group). The first supported vicariance event consisted of an East/West separation of the faunas in all analysed trees; the second supported vicariance event is a North/South separation of the fauna located East of the Andes; the third supported vicariance event was found in the southernmost fauna located East of the Andes, which separates allopatric Patagonian species in a North/South direction; and finally, the fourth supported vicariance event separates in a North/South direction clades of the Central Chilean fauna located West of the Andes. Our results suggest that these four supported vicariance events could be correlated with the uplifting of the Andes and the marine ingressions that occurred during the Cenozoic that is the estimated age at which these events occurred. Finally, we discuss that current software implementation of Hovenkamps ideas need to be expanded, particularly regarding the automated selection of traceable vicariance events.

Taxonomic revision and preliminary phylogenetic analysis of the subgenus Megalostomis ( Scaphigenia ) Lacordaire (Coleoptera: Chrysomelidae)

The subgenus M. (Scaphigenia) Lacordaire includes six species distributed in arid regions of South America. A systematic revision of this subgenus is presented, including re-descriptions and an update of distribution data of the six species. A preliminary cladistic analysis is performed to test the relationships among the species of the subgenus and if the morphological characters used are suitable. A key is presented to separate the seven subgenera of Megalostomis Chevrolat as well as a key for the species of the subgenus M. (Scaphigenia). Male aedeagus internal sac of the nine studied taxa are described and illustrated. This constitutes the first internal sac descriptions for members of this subtribe and could help clarify the homology of such structures within Cryptocephalinae. M. (S) consimilis Achard is reassigned to the species status on the base of genitalic characters. The cladistic analysis was done using forty-one characters from adult external morphology and male and female genitalia. Two species of two different subgenera of Megalostomis: M. (Megalostomis), and M. (Heterostomis) Lacordaire, and one representative of the genus Themesia Lacordaire were selected as out groups. Results were obtained by implicit enumeration using parsimony software. Three equally parsimonious trees were obtained of 45 steps, Ri=0.952, and Ci= 0.941. Support of each group was evaluated by Jacknifing, Bootstrap and Bremer values. Relationships between species are discussed.

The Patagonian Steppe biogeographic province: Andean region or South American transition zone?

America comprises three biogeographic regions: Nearctic, Neotropical and Andean. In between them, two transition zones (TZ) have been proposed: Mexican and South American. The biogeographic provinces belonging to a TZ have no predominance of biotic elements pertaining to each of its bordering regions. Regarding the Andean region, one of its provinces, the Patagonian Steppe, presents a mixture of different biogeographic elements, which are typical of transition zones. Because of this, we assessed whether the Patagonian Steppe belongs to the Andean region or whether it forms the southernmost part of the South American TZ. We gathered phylogenetic information from 177 taxa that inhabit the Patagonian Steppe and established to which biogeographic element they belong. We followed the criterion that an area can be considered as part of a region when at least 70% of its biota has the same origin, that is belongs to the same biogeographic element. In contrast, when the biota of an area presents a similar percentage of its different biogeographic elements, it could be considered as belonging to a transition zone. We found that the Patagonian Steppe presents a similar proportion of genera of Andean as well as neotropical origin. Therefore, we propose that this province should be included in the South American transition zone. Moreover, inclusion of the Patagonian Steppe as part of this TZ will make it the largest TZ of America, encompassing most of the arid lands of South America.

A comprehensive guide to the Argentinian case-bearer beetle fauna (Coleoptera, Chrysomelidae, Camptosomata)

Abstract Knowledge of Argentinian Camptosomata has largely remained static for the last 60 years since the last publication by Francisco de Asis Monrós in the 1950’s. One hundred and ninety Camptosomata species (182 Cryptocephalinae and 8 Lamprosomatinae) in 31 genera are recorded herein from Argentina. Illustrated diagnostic keys to the subfamilies, tribes, subtribes and genera of Argentinian Camptosomata, plus species checklists and illustrations for all genera of camptosomatan beetles cited for each political region of Argentina are provided. General notes on the taxonomy and distribution, as well as basic statistics, are also included. This study provides basic information about the Camptosomata fauna in Argentina that will facilitate in the accurate generic-level identification of this group and aid subsequent taxonomic revisions, and phylogenetic, ecological, and biogeographic studies. This information will also facilitate faunistic comparisons between neighboring countries. Two nomenclatural acts are proposed: Temnodachrys (Temnodachrys) argentina (Guérin, 1952), comb. n., and Metallactus bivitticollis (Jacoby, 1907), comb. n. The following are new records for Argentina: Stegnocephala xanthopyga (Suffrian, 1863) and Lamprosoma azureum Germar, 1824. Currently, the most diverse camptosomate tribe in Argentina is Clytrini, with almost twice the number of species of Cryptocephalini. New records for Argentina are predicted.

Colaspis caligula , a new species found in association with Vitis vinifera (L.) crops in Argentina (Coleoptera: Chrysomelidae)

Some species of Colaspis Fabricius are well-known pests of several crops in Argentina. In this contribution, we describe a new species within this genus: Colaspis caligula n. sp., found in association with Vitis vinifera (Linnaeus) crops. We provide descriptions and illustrations of the mature larva, pupa and adult, as well as notes on its diagnostic characters, life cycle, and the damages produced to the plants.

Estudios sistemáticos, filogenéticos y biogeográficos en insectos de la región austral de América del Sur

La region austral de America del Sur es el area situada por debajo de los 30° S (HUMPHRIES & PARENTI, 1986; CRISCI et al., 1991; ROIG-JUNENT & FLORES, 1994) incluyendo las areas montanosas de los Andes situadas al norte de esta latitud (MORRONE, 1996). Numerosos estudios biogeograficos separan este area del resto del continente americano al considerarla mas estrechamente relacionada con biotas de areas templadas del hemisferio sur, tales como Australia, Nueva Zelanda y Africa del Sur (CRISCI et al., 1991; ROIG-JUNENT, 1993, 2000; SANMARTIN & RONQUIST, 2004). Algunos autores han postulado que America del Sur es un continente de origen hibrido y que deberia ser dividido en dos areas: la templada del sur y la tropical del norte (CRISCI et al., 1991; MORRONE, 2001). A pesar de los muchos trabajos realizados en el campo de la sistematica y la biogeografia de insectos ESTUDIOS SISTEMATICOS, F ILOGENET ICOS Y BIOGEOGRAFICOS EN INSECTOS DE LA REGION AUSTRAL DE AMERICA DEL SUR