New records of Gerridae (Insecta, Hemiptera, Heteroptera) from northern South America

Based on material deposited in a Colombian entomological collection, new records from northern South America (Colombia and Venezuela) are presented for eight species of Gerridae (Insecta, Hemiptera, Heteroptera). The species belong to the genera Brachymetra Mayr, 1865 (Charmatometrinae); Limnogonus Stål, 1868; Neogerris Matsumura, 1913 (Gerrinae, Gerrini); Tachygerris Drake, 1957 (Gerrinae, Tachygerrini); Metrobates Uhler, 1871 (Trepobatinae, Metrobatini); and Telmatometra Bergroth, 1908 (Trepobatinae, Trepobatini). Photographs of the habitus of adults and distribution maps are also presented for each species.

The Orinoco Low-Level Jet and its association with the hydroclimatology of northern South America

We investigated the relationship between the frequency of occurrence of the Orinoco Low-Level Jet (OLLJ) and hydroclimatic variables over northern South America. We use data from the ERA5 atmospheric reanalysis to characterize the spatial and temporal variability of the OLLJ in light of the LLJ-classification criteria available in the literature. An index for the frequency of occurrence of an LLJ was used, based on the hourly maxima of wind speed. The linkages among the OLLJ, water vapor flux, and precipitation were analyzed using a composite analysis. Our results show that during December–January–February (DJF), the OLLJ exhibits its maximum wind speed, with values around 8–10 m/s. During DJF, the analysis shows how the OLLJ transports atmospheric moisture from the Tropical North Atlantic Ocean. During this season, the predominant pathway of the OLLJ is associated with an area of moisture flux divergence located over northeastern South America. During JJA, an area of moisture flux convergence associated with the northernmost location of the ITCZ inhibits the entrance of moisture from northerlies. We also show that the occurrence of the OLLJ is associated with the so-called cross-equatorial flow. During DJF, the period of strongest activity of the OLLJ is associated with the northerly cross-equatorial flow and dry season, whereas during JJA the southerly cross-equatorial flow from the Amazon river basin predominates and contributes to the rainy season over the Orinoco region.

Alfred Russel Wallace and the Models of Amazonian “Indians” Displayed at the Crystal Palace Ethnological Exhibition

This paper discusses Alfred Russel Wallace’s Amazonian ethnography and his collaboration with Robert Latham on the models of indigenous Amazonian peoples that were placed on display at the Crystal Palace ethnological exhibition in 1854. The reception of scholars and the public to this innovative work is also considered. Wallace’s involvement in the first British ethnological exhibition of large proportions was fundamental to the dissemination of his work, which made a valuable contribution to a field of study—the ethnology of South America—that was still in its infancy in Britain, in marked contrast to Portugal, Spain, Germany and France. Wallace’s field observations of indigenous peoples were instilled in the British imagination through the handbook to the exhibition, in which Latham stressed the importance of Wallace’s descriptions to the advancement of the field of ethnology. Indeed, Wallace’s ethnographic accounts were deemed to provide an authoritative supplement to James Prichard’s preliminary and still somewhat limited ethnological map of northern South America, contributing to the creation of a more complete picture of the indigenous Amazonian peoples of Brazil.

ENSO Influence on Regional Atmospheric Circulation and Thermodynamics Over Northern South America

The interannual variability of hydroclimatic conditions in Northern South America (NOSA), specially precipitation, is mainly influenced by the El Niño-Southern Oscillation (ENSO). We explored potential mechanisms that affect precipitation occurrence in NOSA during El Niño and La Niña events over the period 1980-2019, using data from the ERA5 reanalysis. We looked at the atmospheric moisture contribution from different sources using the Dynamic Recycling Model to track water vapour trajectories. Interestingly, conditions with reduced precipitation during El Niño events can take place along with increased precipitable water. To understand this, we analyzed thermodynamic conditions in the atmosphere that are necessary for precipitation to occur over the region, such as convective available potential energy, convective inhibition, lifting condensation level and low--level relative humidity. With this approach, we found more favorable atmospheric conditions for the occurrence of precipitation during La Niña events, even if the content of water vapor was equal or even less than during El Niño events. We also looked at the structure of the regional Hadley circulation in both types of events and found a weakening of the rising motion of the cell during El Niño, which further reduces convective processes over this region. This study provides an integral picture of how precipitation anomalies over NOSA during ENSO events are related both to thermodynamic conditions and sources of atmospheric moisture.

Molecular systematics and genital morphology of the Neotropical cockroaches from the genus Xestoblatta (Blattellidae)

The Neotropics harbors a tremendous diversity of cockroaches yet their evolutionary history is largely unknown. We reconstructed for the first time the phylogeny of the Neotropical genus Xestoblatta Hebard using mitochondrial and nuclear genes from 12 species distributed in Central America and northern South America. Additionally, we conducted a morphological analysis of external characters and male genitalia. In the phylogenetic analysis we recovered the genus Xestoblatta as non-monophyletic, resulting in three unrelated lineages. From the morphological variability described here, we identified three different morphological groups matching the phylogenetic results. The phylogenetic relationships of the three lineages within the Blattellidae were partially resolved. Lineage 1 was nested within a supported clade corresponding to the tribes Blattellini + Symplocini, while lineages 2 and 3 nested within the clade corresponding to the tribe Pseudomopini. Based on our results, we propose to divide Xestoblatta (sensu lato) into three monophyletic genera: Antroxestoblatta gen.n., Sinatablatta gen.n., and Xestoblatta (sensu stricto). We also describe a new species Sinatablatta magdalenensis sp.n. and propose a taxonomic rearrangement for Xestoblatta (sensu lato).

Piper callejasii (Piperaceae), a New Species from the Eastern Slopes of the Andes, Northern South America

A new species of Piper L. (Piperaceae) from the eastern slopes of the Andes in Colombia and Peru, P. callejasii W. Trujillo & M. A. Jaram., is described and illustrated, and morphological comparisons with similar species are discussed. Piper callejasii is distinguished by its stigmas being sessile, rather than on a long style as in four similar species. Its conservation status is suggested to be Endangered.

Cheilanthes ecuadorensis: A New Species of Cheilanthes s. s. (Pteridaceae) from Northern South America

Abstract— Ongoing research on the taxonomically complex genus Cheilanthes (Pteridaceae; Cheilanthoideae) has resulted in the identification of a new species from Loja Province in Ecuador, Cheilanthes ecuadorensis, described and illustrated herein. Originally collected in 1988 and identified as C. cf. rufopunctata, C. ecuadorensis is clearly distinct from that species in having pubescent adaxial blade surfaces and narrow, poorly-differentiated false indusia (rather than the glabrous adaxial surfaces and wide false indusia of C. rufopunctata). Among the South American species currently included in Cheilanthes, C. ecuadorensis is superficially most similar to C. pilosa. However, our molecular phylogenetic analyses indicate that C. ecuadorensis is sister to C. micropteris, the morphologically disparate generitype of Cheilanthes. Here we examine the phylogenetic relationships, morphology, cytogenetics, and geography of these four South American Cheilanthes species in a study that, once again, highlights the importance of herbaria in the process of new species discovery.

The bee genus Psaenythia in northern South America (Hymenoptera: Andrenidae)

The diverse bee genus Psaenythia Gerstaecker (Panurginae, Protandrenini), hitherto known from central and southern South America, is recorded from northern South America for the first time. Two new species are described: Psaenythia diceratops, sp. n., from northeastern Colombia, and P. guaricoensis, sp. n., from central Venezuela. The males of P. diceratops are noteworthy for possessing prominent apicolateral clypeal horns, elongate scythe-like mandibles, and displaying macrocephaly with strong dimorphism. Keywords: Andrenidae, Anthophila, Apoidea, Panurginae, taxonomy, Neotropical