Rodolfo Carrara

First Fossil Assemblage of Darkling Beetles (Coleoptera: Tenebrionidae) from Buenos Aires, Argentina: Evidence of Dry Climate During the Late Pleistocene in the Humid Pampas

Abstract. n Late Pleistocene outcrops exposed in Buenos Aires province, Argentina, represent one of the most informative sources for paleoecological studies on South American fauna and flora. Several proxies have been used for studying Pleistocene environmental conditions in the Pampas, but only a few were based on paleoentomological data. The aims of this study are to present the first record of three species of darkling beetles from the late Pleistocene of Buenos Aires province and to provide new paleoenvironmental information. The sediments containing fossil insects correspond to the Guerrero Member of the Luján Formation and were dated between 12,100 x81± 100 14C BP and 13,400 x81± 200 14C BP. Specimens of Nyctelia picipes (Billberg), Epipedonota cristallisata Waterhouse and Scotobius pilularius Germar were identified. To provide information about past climate, the particular climate requirements of these species were analyzed by using the Mutual Climatic Range method. This association could indicate the first pulse of post-glacial climate recovery and the replacement by the insect fauna currently inhabiting the area. This study is one of the first approaches to the Quaternary paleoentomology of Argentina, and highlights the potential of paleoentomological information, when evaluated in combination with previous knowledge on global climate conditions after the last glacial maximum.

Disentangling the Effect of Climate and Human Influence on Distribution Patterns of the Darkling Beetle Scotobius pilularius Germar, 1823 (Coleoptera: Tenebrionidae)

Abstract. n Scotobius pilularius Germar 1823 (Tenebrioninae: Scotobiini) is mainly distributed in natural temperate and mesic grasslands of the Pampean biogeographic province. However, it is also found in climatically extreme environments such as cold and dry grasslands within the Patagonian biogeographic province. In these extreme environments, S. pilularius is found outside of natural habitats, in areas associated with human settlements. In the present paper, the role of climatic conditions and human settlements as determinants of the observed spatial distribution of S. pilularius in its natural distribution and outside that area is assessed. Three following hypotheses are tested: species occurrence is determined by i) climate; or ii) human settlements; or iii) both climate and human settlements. The results suggest that, while the climate and human settlements hypothesis is consistent with the data acquired within the S. pilularius natural distribution area, only the human influence hypothesis significantly explains its distribution outside of its natural area. This outcome suggests that S. pilularius moved from living in a complete disassociation to human settlements or asynanthropy before human settlements in its natural area, to living in close association with human settlements or synanthropy outside of its natural area.

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.

Fourth International Tenebrionoidea Symposium

The Fourth International Tenebrionoidea Symposium (ITS) was hosted by the Instituto Argentino de Investigaciones de las Zonas Áridas (IADIZA) and the Centro Científico Tecnológico (CCT-CONICET Mendoza) in Mendoza, Argentina on November 25th and 26th, 2015. Researchers from nine countries participated with a total of 31 attendees (Fig. 1). The history of the three first formal international meetings on Tenebrionoidea can be found in the editorial of the Third International Tenebrionid Symposium (Smith et al. 2014). After the Third International Tenebrionid Symposium in Arizona USA, voting was carried out to decide the host city for the next meeting. After over a month of voting, Mendoza, Argentina was chosen to host that meeting. A steering committee was assembled with representatives from Centro Científico Tecnológico (CCT-CONICET) Mendoza, Centro Nacional Patagónico (CENPAT CONICET) Puerto Madryn, Chubut, and the Universidad de Buenos Aires with the objectives of continuing this successful tradition and encouraging tenebrionoid workers from around the world to meet and share their research. Presentations were given on November 25th and 26th, 2015. During the meeting eighteen 20-minute talks and ten posters were given (see http://wiki.mendozaconicet.gob.ar/images/5/5e/ProgrameMendoza symposium.pdf) ranging, as in previous meetings, from species-level revisions to broad scale Tenebrionidae phylogenies, biogeography, and faunistic inventories. In addition, presentations on research using tenebrionid beetles in innovative ways were presented, including: species of Tenebrionidae associated with decaying carcasses, potential adverse effects of volcanic ash on tenebrionid larvae, a fossil darkling beetles assemblage, the effect of climate and human influence on distribution patterns of species of Tenebrionidae, and ecological remarks on epigean tenebrionids and their relationship with anthropic desertification. Presentations were also given on two families beyond Tenebrionidae: Zopheridae and Meloidae (Tenebrionoidea). For the first time, a translator (Dr. Florencia Fernández Campón, English-Spanish) was also available to help facilitate communication among participants. The presentations were received with interest and stimulated thoughtful discussions throughout the meeting. The Sociedad Entomológica Argentina (who also sponsored the meeting) offered several books for sale during the meeting: “Biodiversity of Argentinean Ar thro pods” vol. 2, 3, and 4, and “Catalog of phyto phag ous insects of Argentina and its associated plants”. Group discussions also took place during the symposium on potential large scale tenebrionid projects, the organization of a Proceedings volume from the Symposium, collecting localities and travel-related activities for the post-meeting trip, and potential localities for the Fifth International Tenebrionoidea Symposium. FOURTH INTERNATIONAL TENEBRIONOIDEA SYMPOSIUM