Northwestern Brazil Research Articles

Bartonella spp. in bats from the Brazilian Amazon Forest.

Despite the great diversity of bats (64 species) in the State of Acre, northwestern Brazil, there are no studies on occurrence and diversity of Bartonella spp. in bats in this region. The present study investigated the occurrence and molecular identity of Bartonella spp. in spleen samples (n = 271) from bats of 30 different species from this region, within the Amazon biome. Twenty-one out of 208 (10.1%) samples positive in the PCR for the mammalian gapdh endogenous genes were positive in the qPCR for Bartonella spp. based on the nuoG gene. The two gltA Bartonella genotypes detected grouped with those previously identified in bats from other locations, expanding the diversity of genotypes associated with bats. This study provided the first molecular evidence of the presence of Bartonella spp. in bats in the state of Acre and in bats of the species Lophostoma silvicolum, Vampyressa thyone, Tonatia saurophila and Phyllostomus elongatus.

Kinetics of phosphorus release from sedimentary rocks as a potential source of fertilizers in the Amazon region, Brazil

Brazil is the seventh-largest phosphate producer globally, contributing to almost 3% of total production. Approximately 20% of the country's phosphate output comes from sedimentary sources, while the remaining 80% is of magmatic origin. The growing demand for phosphate has sparked increased interest in identifying new deposits. In northwestern Brazil, a phosphate rocks in the São Benedito Formation, part of the Alto Tapajós Group in the Apuí region of Amazonia, has attracted attention.Twelve outcrops were collected for mineral and chemical analysis, solubility testing in aqueous media, standard tests using citric acid, and P2O5 release kinetics. The raw material consists of compacted gray quartz sandstone containing fluorapatite, glauconite, and siderite. The raw samples exhibited total P2O5 content of up to 6%. Additional elements were assessed, with only CaO and Fe2O3 showing total contents reaching 8.05 wt% and 6.65 wt%, respectively. Kinetic extraction in a 2% citric acid solution revealed a positive correlation between soluble and total contents of CaO and P2O5 indicating apatite composition. The elements showed solubility exceeding 60% within the first 30 min and reaching 100% after 180 min. However, as the fluorapatite and siderite dissolved, the citric acid solution became saturated, halting the dissolution process. These results indicate effectiveness in solubilizing phosphate in samples with less than 4 to 5 wt% of P2O5, meeting the minimum requirements established by the Brazilian Ministry of Agriculture. These characteristics suggest that the São Benedito Formation phosphate rocks have agronomic value for use as direct/natural fertilizers in Brazil's tropical acidic soils.

A new sauropod species from north-western Brazil: biomechanics and the radiation of Titanosauria (Sauropoda: Somphospondyli)

Abstract Titanosaurs were the most diverse sauropod group during the Cretaceous period, with most of its diversity being found during the Late Cretaceous. In this work, Tiamat valdecii, gen. et sp. nov. is described, a new species of basal titanosaur prospected from the Açu Formation (Albian–Cenomanian), Potiguar Basin, Ceará state, north-east Brazil. The new taxon is composed by an associated sequence of anterior to middle caudal vertebrae, being diagnosed by four diagnostic features: a marked accessory tuberosity dorsoventrally developed, located on the prezygapophyses; deeply medioventral excavated articulation facets of prezygapophysis and post-zygapophyses articular facets; presence of developed hypantrum–hyposphene articulations; and short middle centra with a well-marked articular facet for the haemal arch. The phylogenetic analysis reveals that Tiamat valdecii was a basal member of Titanosauria. Tiamat is the first species of Early Cretaceous titanosaur known for the Açu Formation. Biomechanical analysis shows that the tuberosity and excavation of the zygapophyses of the middle caudal vertebrae of Tiamat provide greater stability against shear loads in the amphicoelous vertebrae presented; in addition, they allow greater range of lateral movements without affecting the integrity of the joints. These features may have been an evolutionary alternative for the stability of the middle of the caudal vertebral column. The discovery of T. valdecii in the Açu Formation not only increases the known dinosaur diversity for this unit, but also helps us elucidate part of the first titanosaur radiation.

Climate, vegetation, and fire, during the last deglaciation in northwestern Amazonia

The magnitude of change in climatic conditions and vegetation response to the last deglaciation in various parts of tropical Amazonia is poorly understood and controversial. Analysis of a sediment core e.g. fossil pollen, X-ray Fluorescence (XRF) and charcoal from Lake Malachite on the Hill of Six Lakes in northwestern Brazil provided a deglacial history of climate, vegetation change and fire. Pollen revealed a forested landscape throughout, with shifts in composition that were driven by warming and changes in precipitation. The glacial cooling of c. 4–5 °C had brought species characteristic of cooler climates into the Amazon lowlands and was followed by an initial warming that began at least 19.5 thousand calibrated years before the present (cal kyr BP). Temperature oscillations and changes in precipitation between (18–14.6 cal kyr BP) associated with Heinrich Stadial 1 were observed as wet-dry-wet oscillations similar to some of the previous studies, and were evident in both pollen and XRF data. The pollen spectra were consistent that of a mesic forest before and after the peak of the Last Glacial Maximum. Cool-adapted taxa had previously been described from other cores from the Hill of Six Lakes, and persisted in low abundances until c. 14.1 cal kyr BP. No distinct response to the Atlantic Cold Reversal was evident in our proxy data. The early Holocene was marked by pollen, charcoal, and sedimentary changes that could reflect a peak drought stress on the forest. The large occurrence of charcoal indicating an increase in fires coincided with disturbance elements e.g. Cecropia and Alchornea, that could have been consistent with human disturbance of the forest at c. 10.2 cal kyr BP.

Flood Risk Mapping during the Extreme February 2021 Flood in the Juruá River, Western Brazilian Amazonia, State of Acre

Cruzeiro do Sul, a municipality in Northwestern Brazil is recurrently impacted by floods, particularly along the Juruá River. This study presents a comprehensive flood risk analysis by integrating geoprocessing, remote sensing, and hydraulic modeling techniques. Our objectives are to simulate flood extents, identify high-risk areas, and guide sustainable territorial management. Our findings illustrate that the flood impacts are distributed across urban (27%), agricultural (55%), and forest/grassland (17%) landscapes. Historical records and literature reviews also underscore a recurring pattern of extreme floods in the municipality, notably during February’s La Niña events. Some vulnerable urban neighborhoods were identified: Vila Cruzeirinho, Centro, Miritizal, and Da Várzea. These areas are especially susceptible due to their proximity to the river and increased surface runoff during high flood events. By amalgamating various data sources and methods, this research aids decision making for flood mitigation and urban development, fostering resilience against recurrent flooding events in Cruzeiro do Sul.

Interannual Lightning Variability within the TRMM LIS Dataset Using an ENSO Perspective

Abstract The Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) was used to investigate interannual variability of lightning from 1998 to 2014 within the 38°S–38°N range. Previous studies have indicated that the El Niño–Southern Oscillation (ENSO) phenomenon is one significant contributor to interannual lightning variability, potentially the dominant mechanism on the global scale. This period of 16 years contained four warm- (El Niño), eight cold- (La Niña), and four neutral-phase ENSO years based on the oceanic Niño index. Large magnitude lightning anomalies were found during the warm phase of ENSO, with mean warm-phase anomalies of >10 flashes (1000 km)−2 min−1 in north-central Africa and Argentina. This includes a +35 flashes (1000 km)−2 min−1 anomaly in Argentina during the 2009 El Niño. In general, large-scale anomalies of thermodynamic properties and upper-atmospheric vertical motion coincided with the lightning anomalies observed in both Africa and South America. The anomaly over north-central Africa, however, was characterized by a 6-week shift in the annual lightning maximum with the warm phase, a result of the more complex environmental response to ENSO over the Sahel. The most consistent ENSO anomalies with appreciable lightning were found in southeastern Africa, northwestern Brazil, central Mexico, and the southern Red Sea. Of these, all but the Mexico region had enhanced lightning with the cold phase and suppressed lightning with the warm phase.

Multiple records of the introduced parthenogenetic Smooth-scaled Tegulet, <i>Gymnophthalmus underwoodi</i> Grant 1958, in Puerto Rico

The introduction of invasive species to islands can be devastating to local biota. While many invasive species’successful colonization of new habitats can be attributed to features like high fecundity or low mate selectivity,parthenogenetic species pose a unique threat in their ability to reproduce asexually at high rates. The Smooth-scaledTegulet (Gymnophthalmus underwoodi), first described from Barbados in the 1950s, has since been documented as anintroduced species across additional Lesser and Greater Antillean islands as well as northwestern Brazil and Venezuela.Herein we report multiple individuals from Puerto Rico, including the first genetic records, which indicate that theindividuals on this island are most closely related to populations recorded from Brazil and Montserrat. Additionalgenetic information is necessary to determine the timing and migration of this species across the Caribbean. Regardless,the continued geographic expansion of this parthenogen across the Caribbean could present a threat to local fauna.

Statistical bias correction for CESM-simulated PM2.5

Global climate models are good tools for simulating transnational and interregional transport of pollutants such as PM2.5, which is of growing interest and importance, for example in human health and socio-economic development studies. However, reliable estimates of PM2.5 are very challenging for such relatively coarse and simplified models, and even state of the art models fare poorly in matching satellite observations in many highly polluted, and some almost pristine environments. This work describes a novel bias correction method based on multiple linear regression (MLR) modelling. The target data we aim for is global satellite-based data and the PM2.5 precursors simulated by the Community Earth System Model Version 1.2.2. The statistical method greatly reduced the simulation biases of PM2.5 worldwide compared with satellite-derived PM2.5, especially in highly-polluted regions, such as northern China, the Indo-Gangetic plains, the Democratic Republic of Congo and northwestern Brazil. Root-mean-square differences (RMSD) between continental-averaged observations and simulations are reduced from 75% to 9%. The ensemble RMSD for 13 countries exemplified here is reduced from 116% to 3%. One virtue of the MLR method is that details of the classification of internal mixed modes of each aerosol and their spatial differences are not required. The MLR coefficients are designed to be highly aerosol- and country-dependent, so they provide new perspectives of relative importance of each aerosol to local PM2.5 and offer clues on observational and simulation biases. The bias-correction method is easily applied for air pollutants simulated by global climate models due to its low computational cost.

Cenozoic biostratigraphy of larger foraminifera from equatorial carbonate platform of northwestern Brazil

The off-shore Cenozoic succession of the Pará-Maranhão Basin of the Brazilian equatorial margin is studied to investigate skeletal and foraminiferal assemblages during the Oligocene-Miocene interval, one of the fundamental moments in the environmental evolution of our planet. The material from core 1-MAS-16-MA is analyzed using a combination of conventional paleontological analyses, and innovative approaches like micro-CT scan and U/Pb dating on carbonates. The results allowed to clearly constrain the Oligocene – Miocene interval and divide it into four foraminiferal assemblages and seven biofacies useful for both paleoenvironmental reconstructions and stratigraphic correlations. The paleoenvironmental analysis indicates a common pattern of relative sea-level oscillations with the nearby Foz do Amazonas Basin, highlighting a common behavior of this part of the equatorial passive margin during the Oligocene – Miocene interval. The comparison between the succession of skeletal and foraminiferal assemblages of the investigated core and other successions of the Southern and Central American area indicated the presence of stratigraphically relevant foraminiferal assemblages that could be useful for improving the correlation between the various Cenozoic successions of the area (assemblages dominated by nummulitids and lepidocyclinids in the Rupelian; assemblages dominated by Heterostegina (Vlerkina) antillea, lepidocyclinids, and primitive miogypsinids in the Chattian; assemblages dominated by Heterostegina (Vlerkina) antillea, lepidocyclinids, and miogypsinids other than Miogypsinoides and Miogypsinella, in the Aquitanian; assemblages dominated by advanced miogypsinids in the Burdigalian; post Early Miocene assemblages characterized by the lack of abundant lepidocyclinids and miogypsinids). Finally, the overall resilience of most of the large benthic foraminifera taxa to the Oligocene – Miocene transition testifies once more to the adaptability of this group of carbonate producers.

A new species of Dimeragrion Calvert, 1913 (Odonata: Zygoptera: Heteragrionidae) from Northwestern Brazil.

Dimeragrion Calvert, 1913 is a genus with five species, restricted to the Pantepui region. Here, we describe Dimeragrion baniwa sp. nov. (Holotype. ♂ (LABECO, N° 12276), BRAZIL, Amazonas, São Gabriel da Cachoeira, (0.017, -66.891, 81 m a.s.l.), first-order stream inside Terra Firme Forest, in lateral swamps: 29.xi.2021, C. C. Mendoza-Penagos & M. Gonçalves, leg.), the sixth species of the genus from 13 males and 3 females collected in the municipality of São Gabriel da Cachoeira in the Brazilian Amazon, located at the southern extreme of the Pantepui region. Additionally, we provide photographs of the diagnostic characters of the male and female, photographs of live specimens as well as information on their biology. Finally, identification keys are provided, as well as a distribution map of the species of the genus.

An updated description of Parkia barnebyana (Leguminosae: Caesalpinioideae, mimosoid clade) from Amazonian Venezuela and Brazil, and comparison with other species in sect. Parkia with erect capitula

SummaryAn updated description, including characters of the capitulum and fertile flowers, is provided for Parkia barnebyana. Originally recorded from southern Venezuela, this small canopy tree from igapó (blackwater flooded forest) is now also known by two collections from north-western Brazil. The capitula are yellow and held erect, with the fertile flowers uppermost; they are borne on short, robust, upright peduncles that arise from long compound inflorescence axes projecting directly above the crown. The structure and shape of the capitula place this species in pantropical sect. Parkia and its pod morphology suggests that it lies outside the largely Amazonian nitida-group; both conclusions are supported by a recent phylogenetic analysis. The indehiscent pods remain in the tree at maturity and most seeds are apparently removed by arboreal dispersers and vertebrate seed predators. Two other neotropical species in sect. Parkia, P. cachimboensis and P. decussata, are known to have erect, yellow or largely yellow capitula and in both, a well-developed fringe of staminodia projecting from the basal flowers is absent. Both these species are chiropterophilous and although we predict that P. barnebyana is also likely to be bat-pollinated, we have made no observations. A fourth neotropical species, P. nana, also with yellow flowers, is reported to have erect capitula but they do have staminodial fringes; its pollination has not been studied. Within sect. Parkia, erect capitula occur only in the Neotropics, probably because of the head-down position in which quite large generalist phyllostomid bats land on them to access nectar. Erect capitula appear to have evolved more than once within neotropical sect. Parkia and at least sometimes from ancestors with pendent capitula, but further phylogenetic data are needed to confirm this.

Miocene tropical storms: Carbonate framework approaches and geochemistry proxies in a reservoir model

The Bragantina Platform is an important sedimentary package that occurs in northwestern Brazil, typically around the equatorial western Atlantic coast. Most of the latest Neogene succession of this carbonate-siliciclastic platform consists of the Pirabas Formation of Miocene age (Burdigalian to Serravalian). High-energy coastal storms and hurricanes as a consequence of trade wind anomalies during the Neogene impacted the shallow-water inner marine heterozoan assemblage deposits of the Pirabas Formation. A chaotic overlap of benthic infauna and epifauna, and of demersal and pelagic species in the same section was analyzed using petrography, petrophysics, micro- and macropaleontology, taphonomy, and geochemistry in order to understand sedimentary and paleoenvironmental processes. The equatorial carbonate platform of Brazil reveals high-energy and multiple Miocene tropical storms. This high-energy wave environment caused severe damage to shallow-water heterozoan assemblages at the seafloor, resulting in chaotic faunal arrangements, and removing fine-grained particles thus improving the petrographic properties of the rock (porosity and permeability).

OSL and radiocarbon dating and evidence of palaeo-wildfires in Quaternary deposits of the Tacutu basin, northwestern Brazil

This work presents data on charcoal fragments found in Cenozoic deposits of the Boa Vista Formation and the first absolute dating for this unit. The methodology consisted of the definition of sedimentary facies, as well as the establishment of depositional age using optically stimulated luminescence (OSL) in quartz grains. Analysis was carried on charcoal samples with the help of Scanning Electron Microscopy (SEM), AMS 14C dating, and organic petrography. The facies analysis identified four distinct facies: lateritic massive gravel facies (Gcm1), ferruginous massive gravel facies (Gcm2), massive sand facies (Sm) and fossiliferous massive sand (Smf). The ages of the deposits ranged between 105,2 and 3,2 thousand years before present, indicating that this unit is positioned in the Upper Pleistocene-Upper Holocene transition. The anatomical structures observed in SEM are well preserved and the studied charcoal samples have angiospermic affinity. Two episodes of fires were identified with range ages between 5663 and 3377 cal years BP, with burning temperature varying from 340 °C to 400 °C.

Physicochemical, Sensory, Microbiological And Antioxidant Characterization Of A Jelly Made From Tacinga Inamoena

ABSTRACT Quipá (Tacinga inamoena) is a plant native to Northwestern Brazil which contains valuable minerals in its composition that are of great interest to the scientific community. The purpose of this study was to assess the physicochemical, antioxidant, sensory and microbiological properties of a quipá-based gelatinous sweet. The jelly presented a high concentration of carbohydrates and soluble fibers, being free of microbiological contamination, a good sensorial acceptance, and was therapeutic in terms of antioxidant effects. Due to its ability to chelate copper and ferric ions, the jelly was also responsible for an 80% reduction in DPPH and a preventative activity against oxidative damage. This product contains a high amount of active ingredients, such as phenolic compounds, which have biological benefits effects in disease prevention and health promotion. The quipá jelly provides benefits, functional properties, and advantages, which may be of interest to the industrial sector.

The Metaphysics of Extra-Moderns: On the Decolonization of Thought. A Conversation

In conversation with Peter Skafish Brazilian anthropologist, philosopher, and politi- cal activist Eduardo Viveiros de Castro offers an overview of his thinking, both past and present. After explaining why initially he argued that ontology should be a topic of anthropologists, he discusses his more recent conclusion that indigenous thought should be regarded instead as metaphysical. It is not that La pensée sauvage has an implicit ontology discoverable by the human sciences but, rather, that indigenous people themselves think about metaphysical issues as such. De Castro traces the origins of his position in the ethnographic fieldwork that he undertook in the 1980s with the Araweté of northwestern Brazil and in his and the anthropologist Philippe Descola’s parallel engagements with the structuralism of Claude Lévi-Strauss. De Castro points out the definitive post-structuralist period in Lévi-Strauss’ thought after the first volume of Mythologies when the notion of struc- ture lost its pertinence to give place to the concept of transformation. Although he is usually considered, especially in Anglo-American anthropological community, as a thinker of binary oppositions, Lévi-Strauss’ ultimate goal is to demonstrate the eth- nographic phenomena that cannot be placed in the dualist frames such as famous nature and culture distinction. Finally, Viveiros de Castro addresses the political stakes of ascribing metaphysics to non-modern peoples, clarifying what he means by the “permanent decolonization of thought.” Following the suggestion made by French philosopher Patrice Maniglier, he claims that anthropology as a comparative discipline by definition should play the role of model science that had been ascribed to physics from the outset of modernity until today.

Clinically silent Plasmodium vivax infections in native Amazonians of northwestern Brazil: acquired immunity or low parasite virulence?

Malaria remains common among native Amazonians, challenging Brazil's elimination efforts. We examined the epidemiology of malaria in riverine populations of the country's main hotspot - the upper Juruá Valley in Acre state, close to the Brazil-Peru border, where Plasmodium vivax accounts for > 80% of cases. Participants (n = 262) from 10 villages along the Azul River were screened for malaria parasites by microscopy and genus-specific, cytochrome b (cytb) gene-based polymerase chain reaction. Positive samples were further tested with quantitative TaqMan assays targeting P. vivax- and P. falciparum-specific cytb domains. We used multiple logistic regression analysis to identify independent correlates of P. vivax infection. Microscopy detected only one P. vivax and two P. falciparum infections. TaqMan assays detected 33 P. vivax infections (prevalence, 11.1%), 78.1% of which asymptomatic, with a median parasitaemia of 34/mL. Increasing age, male sex and use of insecticide-treated bed nets were significant predictors of elevated P. vivax malaria risk. Children and adults were similarly likely to remain asymptomatic once infected. Our findings are at odds with the hypothesis of age-related clinical immunity in native Amazonians. The low virulence of local parasites is suggested as an alternative explanation for subclinical infections in isolated populations.

Incidence of Burnout syndrome in Brazilian army military in the amazon region

This study aimed to investigate the Burnout levels and possible predisposing factors among Brazilian Army military who were serving in the Brazilian Amazon. Method: the sample consisted of 122 volunteer military (officers and sergeants) with a mean age of 36.80 ± 6.69 years, 53 were employed in the operational missions (border security, patrol, external and internal defense exercises) and 69 personnel who were employed in the administrative missions (internal logistics). Officers (29) and sergeants (93) were selected who served in Porto Velho, northwestern Brazil. They answered to a sociodemographic questionnaire and the Malash Burnout Inventory, validated for Brazil. Results: scores showed that the levels of burnout in Army military who serve in the region are high. The main sociodemographic, labor, physical and social conditions that were associated with significantly higher levels of Burnout in this study were: reduced length of service, sedentary lifestyle, extra work, lower hierarchical rank and living away from relatives. Conclusion: the interaction between the two instruments found that the military working in the operational area, warrant officers, sergeants, between 6 and 10 years in service, single, who do little physical activity and whose relatives live far away were the ones who had the highest Burnout levels.

Geological knowledge advances on the Alto Rio Negro region, northwestern Amazonian Craton, Brazil: a review

This paper presents a literature review of the geology of the Alto Rio Negro region, located in northwestern Brazil. Firstly, we summarize the Amazonian Craton tectonic models and how the study area fits in these different tectonic models. The aim is to organize the literature data and better guide the consultation for new studies. The first geological reports about the Alto Rio Negro are from the Mid-19th century, when the British naturalist Alfred Russel Wallace travels to this country and, since then, long periods of scientific production absence occur. However, after the RADAMBRASIL Project in the 1970s, there was a significant research advance. Recent publications reveal a complex tectonic evolution, with three events that mark periods of generation and reworking of the Proterozoic basement. Two Paleoproterozoic magmatic arc systems generated the geological basement. The Calymmian collision of these terrains produced a large volume of crustal granites, in addition to pre-, and post-tectonic granites. A crustal reworking period (1.4-1.1 Ga) reactivated the basement structures and, possibly, generated the Ectasian carbonatitic intrusions. There are many difficulties to access this region, so the literature data are of great value and provide a background for new studies. The lack of more detailed geological maps covering the Alto Rio Negro region is the main obstacle. Still, it offers a fertile research field for geologists interested in contributing to diverse research fields of Geology focusing on the Amazonian Craton.

Monthly biological larviciding associated with a tenfold decrease in larval density in fish farming ponds and reduced community-wide malaria incidence in northwestern Brazil

BackgroundLarvicides are typically applied to fixed and findable mosquito breeding sites, such as fish farming ponds used in commercial aquaculture, to kill immature forms and thereby reduce the size of adult malaria vector populations. However, there is little evidence suggesting that larviciding may suppress community-wide malaria transmission outside Africa. Here, we tested whether the biological larvicide VectoMax FG applied at monthly intervals to fish farming ponds can reduce malaria incidence in Amazonian Brazil.MethodsThis study was carried out in Vila Assis Brasil (VAB; population 1700), a peri-urban malaria hotspot in northwestern Brazil with a baseline annual parasite incidence of 553 malaria cases per 1000 inhabitants. The intervention consisted of monthly treatments with 20 kg/ha of VectoMax FG of all water-filled fish ponds in VAB (n ranging between 167 and 170) with a surface area between 20 and 8000 m2, using knapsack power mistblowers. We used single-group interrupted time-series analysis to compare monthly larval density measurements in fish ponds during a 14-month pre-intervention period (September 2017–October 2018), with measurements made during November 2018–October 2019 and shortly after the 12-month intervention (November 2019). We used interrupted time-series analysis with a comparison group to contrast the malaria incidence trends in VAB and nearby nonintervention localities before and during the intervention.ResultsAverage larval densities decreased tenfold in treated fish farming ponds, from 0.467 (95% confidence interval [CI], 0.444–0.490) anopheline larvae per dip pre-intervention (September 2017–October 2018) to 0.046 (95% CI, 0.041–0.051) larvae per dip during (November 2018–October 2019) and shortly after the intervention (November 2019). Average malaria incidence rates decreased by 0.08 (95% CI, 0.04–0.11) cases per 100 person-months (P < 0.0001) during the intervention in VAB and remained nearly unchanged in comparison localities. We estimate that the intervention averted 24.5 (95% CI, 6.2–42.8) malaria cases in VAB between January and December 2019.ConclusionsRegular larviciding is associated with a dramatic decrease in larval density and a modest but significant decrease in community-wide malaria incidence. Larviciding may provide a valuable complementary vector control strategy in commercial aquaculture settings across the Amazon.Graphical abstract

Two new species of oil-collecting bees of Centris (Melanocentris) from Colombia (Hymenoptera: Apidae)

ABSTRACT In this article are described two new species of oil-collecting bees of Centris (Melanocentris) from Colombia. Centris (Melanocentris) marinae sp. nov. occurs in the northeast, César Department, while C. (Melanocentris) germani sp. nov. occurs in the southeast, in the Caquetá, Meta and Vaupés Departments, as well as in the Amazonas State in northwestern Brazil. Photographs of both new species and a distribution map are also presented.