Sofía Copperi

Urban ecosystems form fragmented landscapes characterized by low biodiversity and high impervious surface cover, which can affect insect demography and ecological interactions. In particular, solitary wasps may be especially sensitive to urbanization, given their role as important regulators of insect populations through predation and parasitism. We investigated how different degrees of urbanization affect the nesting ecology of three cavity‐nesting solitary wasps of the genus Trypoxylon . We hypothesized that increasing impervious surfaces limits resource availability, thereby impairing wasp nest construction and reproduction. From October 2021 to April 2022, we used trap‐nests to monthly record Trypoxylon aureovestitum, T. platense and T. rogenhoferi nesting at 55 sites distributed across nine cities in the central region of Argentina, spanning a range of areas and population sizes. At each site, we defined a circular 500‐m radius buffer area where we estimated the degree of urbanization (proportion of impervious surface) and measured flower abundance and richness. Abundance of built nests decreased significantly with increasing urbanization, whereas brood cell abundance per nest, the survival of immature stages, sex ratio and the number of parasitized brood cells at each site did not change with urbanization. The sex ratio differed between species, with a female bias in T. aureovestitum , a male bias in T. platense and no clear pattern in T. rogenhoferi . Furthermore, nest abundance increased with floral richness, while brood cell abundance per nest and parasitoid abundance decreased. Urbanization influenced the abundance of Trypoxylon wasps. Specifically, a decrease in nest abundance with increasing urbanization may reduce population sizes, potentially increasing species vulnerability to local extinction. Furthermore, our results suggest that certain species may be more flexible than others, and hence more likely to survive and thrive, in these anthropogenic settings. Finally, the influence of floral resources on wasp reproduction highlights the complex effects that local plant communities have on the reproductive success and ecological interactions of these solitary wasps.

Se presenta el primer registro del género Ocnaea Erichson, 1840 (Díptera, Acroceridae) para la República Argentina y el primer registro de esta familia parasitando una araña del género Catumiri Guadanucci 2004 (Mygalomorphae, Theraphosidae). Se dan a conocer algunas observaciones del ciclo biológico de la mosca y del comportamiento de la tarántula Catumiri argentinense (Mello-Leitão, 1941).

The genus Homoeomma has thirteen species distributed in Argentina, Brazil, Colombia, Peru and Uruguay. In Argentina, two species are recorded, Homoeomma elegans in Misiones province and H. uruguayense in Buenos Aires, Entre Ríos and Santa Fe provinces. The objective of this work is to provide the first record of Homoeomma uruguayense in the mountainous system of central Argentina, belonging to western record of the genus in this country. In addition, we provide data on natural history of the species, some notes on its sexual behavior and through the species distribution modeling we discussed about the geographic distribu­tion of the species and factors that could led to this pattern.

The family Nemesiidae is the second most diverse family of Mygalomorphae spiders. Acanthogonatus centralis (Nemesiidae) is commonly found in hilly areas of central Argentina. These spiders are considered generalists due to their basal position in the phylogeny, but little is known about the trophic ecology of the species. Therefore, the objectives of this study were to study some of the species' predatory traits, such as feeding frequency and prey acceptance, and to assess its natural diet. In addition, two parameters - attack latency and consumption time - were measured for each accepted prey. We found that A. centralis feeds every two days and accepts almost all prey offered. The most accepted prey items were beetle larvae and termites. In fact, termites were attacked faster than any other prey, suggesting they are a suitable prey for these spiders. In regard to the species' natural diet, we found remains of seven prey items, ants and beetles being the most frequent. In this study, we found that Acanthogonatus centralis is polyphagous since it accepts different kinds of prey.

Scorpions are one of the most important taxa for ecological, conservation, and biogeographic studies. Biodiversity in the pampean grassland hilly environment is relevant because of the high number of native plant and animal taxa. We studied the diversity, abundance and phenology of a scorpion community in a natural reserve from central Argentina. Samples were taken monthly using 10 pitfall traps. Five species of scorpions (269 individuals) were observed in the study site (Bothriuridae). Bothriurus prospicuus was the most abundant species with 40.15% of the total individuals captured. The Shannon index was H´ = 0.69 and the evenness index was 0.83. Scorpion abundance was significantly different between months and was significantly correlated with monthly mean temperature. The knowledge on the scorpion fauna in “Ernesto Tornquist” Provincial Park could help in the preservation of natural grassland habitats.

This is the first record for the tarantula Vitalius longisternalis Bertani, 2001 in Parana and Araucaria Forests, Misiones province, northeastern Argentina. Specimens were found at Iguazú National Park and Urugua-í Wildlife Reserve. Data on its natural history is provided.Tarantula, Parana, Araucaria Forest, distribution extension