Andes Of Southern Peru Research Articles

The impact of agriculture on tropical mountain soils in the western Peruvian Andes: a pedo-geoarchaeological study of terrace agricultural systems in the Laramate region (14.5° S)

Abstract. This integrated pedo-geoarchaeological study focuses on three abandoned pre-Hispanic terrace agricultural systems near Laramate in the southern Andes of Peru (14.5° S), aiming to unravel the pedological and land-use history of the region, which served as a significant agricultural hub during pre-Hispanic times. The key objectives of the investigation involved contextualizing the former agricultural management system within its geomorphological and palaeoecological framework and assessing the impact of agricultural practices on soil development and quality by comparing non-irrigated agricultural terrace soils with their undisturbed palaeo-pedological counterparts. The Laramate terrace complex, with its diverse terrace systems and varied geomorphological and geological settings, provided an ideal setting for the investigation. This comprehensive examination integrated a range of methodologies, including field surveys, digital mapping, and geomorphological analysis based on GIS and remote sensing applications, soil analysis (e.g. grain size, bulk chemistry, nutrient budget), plant microfossils (phytoliths and starch), and radiocarbon dating. In the Laramate region, the geomorphological setting of terrace agricultural systems promotes their optimal functioning. The terraces are often located in sun-sheltered areas with western exposure on middle and lower slopes or valley bottoms, which mitigate intense solar radiation, reduce evapotranspiration, increase soil moisture, and minimize erosion. The study identifies three soil groups in the Laramate region: Phaeozems, Andosols, and Anthrosols. Unique characteristics of Phaeozems challenge typical descriptions, influenced by factors such as climatic seasonality, vegetation, fauna, lithology, and aeolian inputs. The terrace soils in the Laramate region are classified as Terric Anthrosols, showing no significant degradation even after long-term use. Their balanced acidity and nutrient levels support Andean crop cultivation. Traditional non-mechanized tools, such as the chaquitaclla and rucana, likely minimized soil disruption. The terrace tillage horizons have high organic matter, indicating intentional organic manuring. Phytolith concentrations suggest intensive agricultural activity, particularly maize cultivation, with varying patterns suggesting changes in cultivation, fertilization, or mulching practices over time. Starch grain identification aligns with phytolith analyses, reinforcing maize's significance in the region. Although the use of animal-origin fertilizers requires further investigation, there is no evidence of nutrient maintenance through seasonal burning. Irrigation was minimal, and the abandonment of the pre-Hispanic cultivation system was unlikely due to soil exhaustion or terrace instability. Overall, the pre-Hispanic history of terrace agriculture in the Laramate region extends over four development phases, reflecting dynamic interactions between environmental, cultural, and agricultural factors. The initial phase, from the Formative Paracas period to the Early Nasca period (800 BCE–200 CE), witnessed the establishment of agricultural terraces with simple terrace architecture, while the Middle Horizon (600–1000 CE) saw systematic areal expansion influenced by the Wari culture. Adaptations to drier conditions included terrace agriculture on volcanic soils. The Late Intermediate period (1000–1450 CE) witnessed hydrological variability and further terrace expansion to lower altitudes and less agriculturally suitable locations. The final phase, marked by the onset of the Hispanic colonial period in 1535 CE, saw the gradual abandonment of terrace agricultural systems due to demographic shifts and reorganization of production systems. Despite this, the historical trajectory underscores the adaptability and resilience of pre-Hispanic communities in the Laramate region, showcasing innovative terrace agriculture as a means of coping with changing environmental conditions across diverse landscape units.

Seasonal Effects of Wildfires on the Physical and Chemical Properties of Soil in Andean Grassland Ecosystems in Cusco, Peru: Pending Challenges

Soils are a valuable renewable resource on human timescales, and they interact with distinctive grassland ecosystems characterized by unique biodiversity and essential provision of ecosystem services, such as water supply and carbon sequestration. However, knowledge of the effects of wildfires on soil properties and nutrient availability in the Andes remains limited. Andean grasslands are currently one of the ecosystems of the Peruvian Andes most affected by wildfires. Our objective is to analyze the effect of fire activity on the physicochemical properties of soil and analyze its social context in Cusco, in the southern Andes of Peru. Soil samples were collected during five periods, spanning both the dry and rainy seasons, to characterize changes in soil properties and monitor vegetation recovery post-fire in two local communities dedicated to livestock activities. The vegetation restored after the wildfire was measured by the “step transect” method. Post-fire changes in soil properties indicate slight increases in pH, electrical conductivity, organic matter, nitrogen, phosphorus, and potassium during the onset of the rainy season; thereafter, a gradual reduction in these values was observed. This reduction can be attributed to leaching associated with the seasonal rainfall and runoff regime. Our findings indicate that one-year post-fire, the biomass in burned areas is reduced to 30–46% of the biomass in unburned areas. A complete regeneration is likely to occur in up to 4 years; this assertion is supported by the perceptions of the affected population, as expressed in interviews conducted in the two farming communities. These results are significant for decision-makers formulation of policies and regulations regarding grasslands and their seasonal restoration.

The Evolution of Agrarian Landscapes in the Tropical Andes.

Changes in land-use practices have been a central element of human adaptation to Holocene climate change. Many practices that result in the short-term stabilization of socio-natural systems, however, have longer-term, unanticipated consequences that present cascading challenges for human subsistence strategies and opportunities for subsequent adaptations. Investigating complex sequences of interaction between climate change and human land-use in the past-rather than short-term causes and effects-is therefore essential for understanding processes of adaptation and change, but this approach has been stymied by a lack of suitably-scaled paleoecological data. Through a high-resolution paleoecological analysis, we provide a 7000-year history of changing climate and land management around Lake Acopia in the Andes of southern Peru. We identify evidence of the onset of pastoralism, maize cultivation, and possibly cultivation of quinoa and potatoes to form a complex agrarian landscape by c. 4300 years ago. Cumulative interactive climate-cultivation effects resulting in erosion ended abruptly c. 2300 years ago. After this time, reduced sedimentation rates are attributed to the construction and use of agricultural terraces within the catchment of the lake. These results provide new insights into the role of humans in the manufacture of Andean landscapes and the incremental, adaptive processes through which land-use practices take shape.

Insight into the 1 December 2016 Mw 6.2 Juliaca Earthquake, Southern Peru, by InSAR Observations and Field Investigation

On 1 December 2016, an Mw 6.2 earthquake characterized by normal faulting occurred in the highlands of the central Andes in southern Peru, marking the region’s largest shallow event. The occurrence of the earthquake provides a significant chance to gain insight into the regional tectonic deformation and the seismogenic mechanism of the shallow normal-faulting earthquake, as well as the regional potential seismic risk. Here, we first utilize Sentinel-1A interferometric synthetic aperture radar (InSAR) data to extract the coseismic and postseismic deformation associated with this earthquake and then determine the detailed coseismic slip and postseismic afterslip distribution of this event. Coseismic modeling results indicate that the coseismic rupture is mainly characterized by normal faulting with some dextral strike-slip components. Most coseismic slip is confined to a depth range of 2–12 km, indicating an obvious slip deficit area in the shallow fault part. Further postseismic modeling reveals that the majority of afterslip is concentrated at depths of 0 to 5.4 km. The relatively shallow postseismic afterslip makes up for the coseismic slip deficit area to some extent. Through a joint analysis of the inversions, seismic data, and regional geology and geomorphology, we infer that the occurrence of this 2016 normal-faulting event is a result of regional gravitational collapse. In addition, we investigate the relationship between the 2016 earthquake and great historical earthquakes near the subduction zone of the central Andes and find that the 2016 event is likely promoted in advance by these events through our calculations of the coseismic and postseismic Coulomb stress changes. Finally, we should pay more attention to the nearby Falla Huaytacucho-Condoroma fault and the western segment of the Vilcanota Fault because of their relatively high stress loading.

Catholic Churches of the Colonial Period in the Southern Andes of Peru: An Evocation towards the Past

Catholic Churches of the Colonial Period in the Southern Andes of Peru: An Evocation towards the Past

In the land of the apu: Cerro Llamocca as a sacred mountain and central place in the pre-Columbian Andes of southern Peru

Cerro Llamocca is a mountain with a summit elevation of 4,487 m asl in the southern Peruvian Andes. This paper presents a first overview of recent archaeological and paleoenvironmental research in its vicinity, and introduces new results from archaeological surveys and strontium isotope analyses. Our survey data show how the wider Cerro Llamocca area comprises an extensive complex of archaeological sites, composed of different sectors with public, domestic, and funerary architecture and rock shelters, occupied throughout the pre-Columbian period from the Early Archaic to the European invasion in 1532. Despite the extreme living conditions of this high-elevation environment, Cerro Llamocca includes the oldest archaeological site hitherto recorded in the larger region: a rock shelter (PAP-969) on its south-eastern slope with evidence of human occupation in the Early Archaic period ∼ 8000 BCE. Human activity in the Cerro Llamocca area reached its zenith in the Middle Horizon (CE 600–1000), at a time of a dry climate and when an expansive Wari state incorporated the worship of mountain deities into an imperial strategy to dominate local people. Our strontium isotope analyses of archaeological human dental enamel from a funerary rock shelter (PAP-942), alongside modern plants as reference data, indicate that the people buried here originated in the adjacent highlands. At a broader level, we study the roles of Cerro Llamocca as a sacred mountain or apu and central place over a long-term perspective, and how these functions integrated and focused religious, ritual, social, political, and economic activities over this high-altitude complex. Its central place function was linked to its sacredness, but also to its topography, provision of shelter, and geographical proximity to a range of critical resources such as water, creating resource dependencies that shaped socio-economic cooperation and exploitation. Although Cerro Llamocca has progressively lost many of these roles since the beginning of the colonial period, local communities continue to revere it as a sacred mountain today.

New age constraints on the break-up of Rodinia and amalgamation of southwestern Gondwana from the Choquequirao Formation in southwestern Peru

Abstract The Choquequirao Formation is a >3 km-thick amphibolite-grade succession that outcrops in the Central Andes of southern Peru. To constrain its age and tectonostratigraphic setting, detrital zircon and metamorphic zircon, titanite, and rutile U–Pb isotopic analyses were conducted. Mantle-derived c. 640 Ma detrital zircons constrain the maximum age of the lower part of the succession and 550–490 Ma metamorphic zircon domains constrain its minimum age. The absence of early Paleozoic detrital zircons suggests that deposition predated early Paleozoic orogenesis in southwestern Gondwana. The close similarity of detrital zircon age spectra to those from sediments deposited on the Arequipa basement suggests that the Choquequirao Formation was deposited on the Arequipa Terrane. Metamorphic titanite dates are highly overdispersed, yet they overlap with c. 460 Ma peak metamorphism recorded by metamorphic zircon. Pb-loss pathways displayed by metamorphic titanite have a lower intercept that overlaps with c. 325 Ma metamorphic rutile, which corresponds to Hercynian orogenesis. A poorly constrained upper intercept of c. 510 Ma may correspond to Pampean and/or early Famatinian orogenesis. We interpret the Cryogenian–Ediacaran Choquequirao Formation as having been deposited during the opening of the Palaeo-Iapetus (Puncoviscana–Clymene) Ocean between eastern Arequipa and southern Kalahari prior to the subsequent collision with southwestern Amazonia during the Pampean Orogeny.

Summertime precipitation extremes and the influence of atmospheric flows on the western slopes of the southern Andes of Perú

AbstractAlthough climatologically dry, the western slopes of the southern Andes of Peru (WSA) can experience precipitation extremes (PEs) during the summer (December–February) resulting in great economic and human losses. Generally, WSA has a positive upslope gradient in precipitation, meaning more rain falls at higher elevations, but observations have shown this gradient can become negative with higher rainfall near the coastal cities. In this study we analyse 2000–2019 regional atmospheric patterns associated with different upslope precipitation gradients and PEs in WSA using principal component analysis methods and surface station observations. Results show important changes in the atmospheric circulation patterns during the occurrence of PE events. A prevailing pattern of negative southerly wind anomalies and regional warming of the southeastern Pacific Ocean leads to significant increases in moisture along the coast of WSA. Eastern moisture flows associated with the presence of the Bolivian High are observed at upper levels of the atmosphere and transport water vapour from the Amazon to the western side of the Andes. Additionally, there is a blocking effect aloft in response to an intense gradient of geopotential height that attenuates the easterly circulations. These large‐scale mechanisms act to concentrate high precipitable water amounts and high levels of convective available potential energy in the troposphere which favours the vertical velocities essential to trigger PEs. These results increase our knowledge of the large‐scale characteristics of PEs to help with forecasting these impactful events and protecting the more than 1.8 million people living in WSA.

La Familia versus The Family: Matriarchal Patriarchies in Peruvian Mormonism

By sacralizing the Western categories of gender and kinship and by exalting the husband-centric, nuclear version of family, The Church of Jesus Christ of Latter-day Saints not only alienated its transgender and feminist members, but also its Peruvian families. This study employs ethnographic encounters, kinterm linguistics, and home décor analysis to situate the existence of Peruvian Mormon matriarchies in the context of a phallocentric religion that spanned two strikingly different, patriarchal societies: one in the Southern Andes of Peru and the other in the US state of Utah. Thus situated, the article then dwells on the transcribed oral history of Ofelia, a Peruvian single mother who utilized the power of the male-only Mormon priesthood to preside over her household as the acting matriarch. Ofelia’s fealty to patriarchy during the very enactment of forbidden priestesshood brings to the fore the profound contradictions that some Peruvian Mormons in the late 2010s disentangled as they sought to become legible to their church as participants in eternal families.

A site formation model for Cuncaicha rock shelter: Depositional and postdepositional processes at the high‐altitude keysite in the Peruvian Andes

AbstractWe report results from geoarchaeological investigations at Cuncaicha rock shelter (4480 m above sea level) in the high Andes of southern Peru. Using field observations, geomorphological, micromorphological, micro‐Fourier transform infrared spectroscopy, Bayesian modeling of radiocarbon ages, and archaeological data, we analyzed the entire stratigraphic sequence to determine depositional and postdepositional processes and agents to assess the impact of bioturbation and to correlate the deposits with regional paleoenvironmental information. The archaeological record is represented well on a microscale, and bioturbation has not destroyed the stratigraphic integrity. The Terminal Pleistocene sediments that contain the oldest archaeological material at the site, dating to ~12.3–11.1 ka, are especially well preserved and capped by a layer of tufa. Depositional changes from autochthonous carbonate precipitation during the Terminal Pleistocene toward allochthonous aeolian sedimentation in the Early Holocene reflect changing environmental and climatic conditions. Formation of a soil during the Late‐Middle Holocene caused postdepositional alterations and likely correlates to variable environmental conditions. We use these results to formulate a site formation model for Cuncaicha rock shelter that integrates archaeological, chronological, and paleoenvironmental data.

Toxic endurance and social becoming: Environmentalism in the shadows of Andean extraction

As industrial mining has expanded its global frontiers so too have critiques of the environmental impacts on isolated peasant and indigenous populations. In the Andes of southern Peru, contemporary mining enfolds impoverished and ‘forgotten’ regions into the promises of bright new futures, animated by the promises of extractive development discourse. In doing so, contemporary industrial mining enacts and evokes latent forms of ‘social becoming’. While the poisonous consequences of living in the vicinity of extraction and environmental degradation are popularly known, they are understood, initially, as a price to be paid for development and historical neglect. The ‘externalities’ of industrial promise for local populations require what this paper terms as ‘toxic endurance’. However, ‘endurance’ is an exhaustible and unequally distributed quality, and calculations must consistently be recalibrated to determine whether silence and uncertainty remain viable strategies in the Andean search for a ‘better life’. Through the parameters and limits of endurance, and contrary to assumptions, this paper will highlight the incentives for complicity with, and acquiescence towards, environmental degradation by those in the precarious shadows of mining.

Una nueva especie de lagartija del género Liolaemus (Iguania: Liolaemidae) endémica de la Puna del sur de Perú

The Andes of southern Peru contain a biodiversity with high degree of endemism due to itspeculiar geography and bioclimate. In this work a new endemic species of the genus Liolaemusis described which would be restricted to an altitude between 3870–4100 m s.n.m., in theSalado river basin of the district and province of Espinar, department of Cusco. This speciesis characterized by the unique combination of morphological characters and the color patternthat distinguish it from the rest of the species of the genus Liolaemus, mainly within of L. ortiziclade of the L. montanus group, where the new species is located according to our phylogenetichypothesis based on morphological evidence presented in this study.

Spatiotemporal patterns of ENSO‐precipitation relationships in the tropical Andes of southern Peru and Bolivia

AbstractPrecipitation in the outer tropical Andes is highly seasonal, exhibits considerable interannual variability, and is vital for regulating freshwater availability, flooding, glacier mass balance, and droughts. The primary driver of interannual variability is El Niño Southern Oscillation (ENSO), with most investigations reporting that the El Niño (La Niña) results in negative (positive) precipitation anomalies across the region. Recent investigations, however, have identified substantial spatiotemporal differences in ENSO‐precipitation relationships. Motivated by the dissimilarity of these findings, this study examines a carefully selected data set (≥ 90% completeness) of ground‐based precipitation observations from 75 high‐elevation (≥ 2,500 m above sea level) meteorological stations in the tropical Andes of southern Peru and Bolivia for the period 1972–2016. Distinct groups of stations and associated variability in precipitation characteristics (e.g., total seasonal precipitation, wet season onset, and wet season length) are identified. Using no spatial constraints, the K‐Means algorithm optimally grouped stations into five easily identifiable groups. The groups farthest from the Amazon basin had significant negative (positive) precipitation anomalies (p < .05) during El Niño (La Niña), aligning with the traditional view of ENSO‐precipitation relationships while groups closest to the Amazon had opposite relationships. Additionally, though studies have reported delays in the wet season, years characterized by El Niño had an earlier wet season onset in all five groups. These findings may aid in improving seasonal climate prediction and managing water resources, and could allow for improved interpretation of tropical Andean ice cores.

The Subnival Vegetation of Moquegua, South Peru: Chasmophytes, Grasslands and Cushion Communities

The present work is a phytosociological synthesis and syntaxonomic overview of the vegetation of the highest subnival parts (superpuna) of the open alpine vegetation of the high plateaus (puna) of the Andes of Moquegua, South West Peru, as related to the main environmental gradients. Using TWINSPAN and DCA ordination analysis, 153 phytosociological relevés were analyzed. For each association, subassociation and community, the syntaxonomy, floristic diversity and relation with environmental variables are described. The syntaxonomy and synecology of superpuna vegetation was studied in 19 localities at an altitude of 4450–4800 m. The study area has a pluviseasonal climate with yearly rainfall (December-April). Four main highland vegetation types were distinguished: 1. slope and scree chasmophyte vegetation composed of shrubs, cushions, ground rosettes and grasses, 2. grasslands (grazed and ungrazed) characterized by great species richness in shrubs, cushions, ground rosettes, grasses and herbs, 3. vegetation of plateaus with cushions, shrubs, ground rosettes, herbs and grasses and 4. nitrophilous vegetation with high cover and low species richness. Within the vegetation of the orotropical and cryorotropical bioclimatic belts three phytosociological classes can be distinguished: Argyrochosmetea niveae (chasmophytic vegetation), Calamagrostietea vicunarum (grasslands with cushions), Anthochloo lepidulae-Dielsiochloetea floribundae (highland slopes and plateaus) and a nitrophylous community. One new association from rock and scree slopes was described within the Saxifragion magellanicae (Argyrochosmetea niveae). Within the Calamagrostion minimae, which comprises grasslands with cushions and mat-forming plants, one new association with two subassociations could be distinguished. Within the grassland and cushion associations of the Azorello-Festucion (Calamagrostietea vicunarum), three new associations were described, comprising nine subassociations. In the Anthochloo-Dielsiochloetalia one new and one previously described association and one community are distinguished. In addition, the nitrophilous community of Tarasa nototrichoides and Urtica flabellata has been described. In total the vegetation comprised 172 vascular species belonging to 32 families. Our study provides the first syntaxonomic revision of chasmophytes, cushion associations and high-altitude grasslands in the Andes of North Moquegua. The proposed syntaxonomic scheme contains the associations distributed under similar habitat conditions throughout the Southern Andes of Peru, but also the associations reflecting the local floristic and environmental patterns. The subnival vegetation of Moquegua hosts some rare endangered and/or protected plant species.

A new species and a new record of Pero Herrich-Schäffer, 1855 (Lepidoptera, Geometridae) in the Andes of southern Peru

Two species of the moth genusPeroHerrich-Schäffer, 1855 (Lepidoptera, Geometridae, Ennominae, Odontoperini) are added to the fauna of the Andes of southern Peru in the Arequipa Department.Pero lopeziVargas & Palaciossp. nov.is described and illustrated based on male adults collected in Pocsi, at 2900 m elevation.Pero atridiscaDognin, 1906, previously known from Angasmarca (La Libertad), is recorded for the first time in Arequipa, significantly expanding its distribution range.

A combined view on precipitation and temperature climatology and trends in the southern Andes of Peru

AbstractIn the southern Peruvian Andes, communities are highly dependent on climatic conditions due to the mainly rain‐fed agriculture and the importance of glaciers and snow melt as a freshwater resource. Longer‐term trends and year‐to‐year variability of precipitation or temperature severely affect living conditions. This study evaluates seasonal precipitation and temperature climatologies and trends in the period 1965/66–2017/18 for the southern Peruvian Andes using quality‐controlled and homogenized station data and new observational gridded data. In this region, precipitation exhibits a strong annual cycle with very dry winter months and most of the precipitation falling from spring to autumn. Spatially, a northeast–southwest gradient in austral spring is observed, related to an earlier start of the rainy season in the northeastern part of the study area. Seasonal variations of maximum temperature are weak with an annual maximum in austral spring, which is related to reduced cloud cover in austral spring compared to summer. On the contrary, minimum temperatures show larger seasonal variations, possibly enhanced through changes in longwave incoming radiation following the precipitation cycle. Precipitation trends since 1965 exhibit low spatial consistency except for austral summer, when in most of the study area increasing precipitation is observed, and in austral spring, when stations in the central‐western region of the study area register decreasing precipitation. All seasonal and annual trends in maximum temperature are larger than trends in minimum temperature. Maximum temperature exhibits strong trends in austral winter and spring, whereas minimum temperature trends are strongest in austral winter. We hypothesize, that these trends are related to precipitation changes, as decreasing (increasing) precipitation in spring (summer) may enhance maximum (minimum) temperature trends through changes in cloud cover. El Niño Southern Oscillation (ENSO), however, has modifying effects onto precipitation and temperature, and thereby leads to larger trends in maximum temperatures.

Diagnosing an ancient shallow-angle subduction event from Cenozoic depositional and deformational records in the central Andes of southern Peru

The spectrum of responses exhibited by upper plates to changes in the subduction zone geometry remains poorly constrained. In the Paleogene, the central Andes in southern Peru potentially experienced an episode of flat or shallow-angle subduction. Presented here are new geochronologic, thermochronologic, basin subsidence backstripping analysis, and 2D flexural modeling results. These are synthesized with existing records on the temporal variation of the volcanic arc position, basin fill chronostratigraphy, deformation style and location, and geophysical constraints on lithospheric architecture to investigate how this segment of the Andes developed during a proposed ancient modification to the subduction zone dip. Basin chronostratigraphy confirms persistent contribution from volcanic arc products during the Eocene–Miocene, arguing against complete cessation of arc magmatism. Sediment accumulation was pulsed and generally more rapid during the late Eocene–Oligocene event. The subsidence curve is generally concave-up, atypical for a foreland basin situated within the compressional central Andes. The tectonic subsidence magnitude observed from backstripping analysis is at least 1 km less than the magnitude of subsidence predicted by 2D flexural model results. This suggests a component of basin uplift, potentially as a dynamic response to subduction shallowing, may have opposed flexural subsidence that was driven by crustal thickening and topographic loading. New geo- and thermochronologic results constrain the timing of Late Triassic pluton emplacement, and initial unroofing that predates the proposed timing of flat or shallow-angle subduction. This new timing suggests initial deformation, with mixed thin- and thick-skinned deformation style, in the Eastern Cordillera may be linked to reactivation of inherited structures rather than inboard deformation advance as a response to subduction flattening. The lack of basement-cored uplifts, preservation of mantle lithosphere beneath this segment of the central Andes, and volcanic arc patterns argue against the occurrence of a flat slab event. Instead, these results point to a shallow-angle subduction event and highlight the diverse behaviors of Cordilleran margins affected by variable subduction zone geometry and upper plates with inherited crustal heterogeneities.

Schizaraeus fouquei sp. nov., the first record of Schizaraeus from Peru (Coleoptera: Tenebrionidae: Stenosini)

A new species of Stenosini (Coleoptera: Tenebrionidae: Pimeliinae), Schizaraeus fouquei sp. nov. is described from southern Andes of Peru: Apurímac and Cusco regions. Prior to this study, Schizaraeus Kulzer, 1955 was monotypic with one species, S. acuticosta Kulzer, 1955 from Catamarca Province in Argentina. We present habitus photographs of both species, scanning electron micrographs of external morphology of the new species, a distribution map, and a comparison of the characters of both species of the genus.

Optimal mesh design methodology considering geometric parameters for rock fragmentation in open-pit mining in the Southern Andes of Peru

Blasting is one of the most important stages in the productive process of a mine due to its direct impact on rock fragmentation, which determines the degree of productivity of operations and the extraction costs generated. In this scenario, an optimized methodology is presented for designing blasting meshes by using mathematical models that help calculate the geometric parameters of a blasting mesh, such as burden, considering the variables of the rock mass and the type of explosive to measure its impact on rock fragmentation and loading productivity (tons/hour). The main advantage of this method is the reliability of the design, which takes into account a greater number of variables that influence fragmentation and uses the principle of distribution and amount of energy in an optimal way. The results obtained in the case of application show that a change in design (2.7 x 2.7 square mesh to 2.2 x 2.5 triangular mesh) reduces P80 by 65%, from 17 to 6 inches, approximately. Additionally, the results show that greater operational efficiency was achieved by increasing excavator productivity by approximately 15.6%.

First record of Alucita danunciae (Lepidoptera: Alucitidae) in Peru

ABSTRACT The little-known Alucita danunciae Vargas, 2011 (Lepidoptera: Alucitidae) is recorded for the first time from Peru, expanding its altitudinal, geographic and host plant ranges. Its larvae were found on fruits of Tecoma fulva arequipensis (Bignoniaceae) at 2900 m elevation in Pocsi, Arequipa, on the western slopes of the Andes of southern Peru. Genetic divergence between the Chilean (type locality) and Peruvian DNA barcode haplotypes was 0.6–0.9% K2P.