ABSTRACT
Natural pest and weed regulation are essential for agricultural production, but the spatial distribution of natural enemies within crop fields and its drivers are mostly unknown. Using 28 datasets comprising 1204 study sites across eight Western and Central European countries, we performed a quantitative synthesis of carabid richness, activity densities and functional traits in relation to field edges (i.e. distance functions). We show that distance functions of carabids strongly depend on carabid functional traits, crop type and, to a lesser extent, adjacent non-crop habitats. Richness of both carnivores and granivores, and activity densities of small and granivorous species decreased towards field interiors, whereas the densities of large species increased. We found strong distance decays in maize and vegetables whereas richness and densities remained more stable in cereals, oilseed crops and legumes. We conclude that carabid assemblages in agricultural landscapes are driven by the complex interplay of crop types, adjacent non-crop habitats and further landscape parameters with great potential for targeted agroecological management. In particular, our synthesis indicates that a higher edge-interior ratio can counter the distance decay of carabid richness per field and thus likely benefits natural pest and weed regulation, hence contributing to agricultural sustainability.
Subject(s)
Agriculture , Fabaceae , Crops, Agricultural , Europe , PhenotypeABSTRACT
Pest responses to landscape complexity show variable patterns globally, primarily related to species traits and specific managed habitats. Leaf-cutting ants (LCAs) are native insects and important pests of plantation forests in South America. We evaluated the responses of LCA nests in young Eucalyptus plantations to different spatial contexts: land uses, interfaces (adjacent land use pairs), agroecosystems, and landscapes. We selected 30 sites in the littoral region of Argentina representing three types of land uses neighboring Eucalyptus plantations: adult eucalypt plantations, citrus plantations, and semi-natural habitats. At each site, we quantified and identified LCA nests and characterized landscape composition and configuration in circles of 250 m radius. LCA nest abundance and presence were similar across different land uses, interfaces, and agroecosystems. Nest presence decreased in landscapes with increasing mean perimeter/area ratio and citrus coverage, whereas LCA abundance showed a similar trend. This indicates that heterogeneous landscapes and those with greater citrus plantation coverage were less likely to have LCA nests. Our findings suggest that landscape configuration was the main predictor of the LCA presence. Understanding the dynamics of LCAs populations and their complex associations with landscape components will contribute to developing successful environmental pest management strategies for plantation forests.
Subject(s)
Ants , Eucalyptus , Animals , Ecosystem , Forests , Insecta , ArgentinaABSTRACT
Winter represents a challenging period for insects inhabiting temperate regions. A plethora of studies have investigated how environmental conditions such as temperature affect insect overwintering success. However, only a few studies have focused on biotic factors and the mechanisms affecting the overwintering performance of insects. Here, we investigated the effects of the parasitic fungus Hesperomyces virescens on the overwintering performance and immune system functioning of the invasive ladybird Harmonia axyridis. Winter survival was significantly lower for infected than for uninfected ladybirds. Body mass loss during overwintering tends to be higher for infected individuals compared to uninfected ones and for larger ladybirds. In addition, parasitic infection reduced post-winter longevity without food in male but not female ladybirds. Total haemocyte and protein concentration as well as antimicrobial activity against Escherichia coli significantly decreased during ladybird overwintering. However, haemolymph parameters were only poorly affected by Hesperomyces infection, with the exception of antimicrobial activity against E. coli that tended to be higher in infected ladybirds. Interestingly, none of the pre-winter haemolymph parameters were good predictors of ladybird winter survival. Overall, our results indicate that energy exhaustion unrelated to immune system challenge is the most probable explanation for increased overwintering mortality in infected ladybirds.
Subject(s)
Anti-Infective Agents , Coleoptera , Animals , Coleoptera/microbiology , Escherichia coli , Humans , Immune System , Insecta , Male , SeasonsABSTRACT
Current climate change is disrupting biotic interactions and eroding biodiversity worldwide. However, species sensitive to aridity, high temperatures, and climate variability might find shelter in microclimatic refuges, such as leaf rolls built by arthropods. To explore how the importance of leaf shelters for terrestrial arthropods changes with latitude, elevation, and climate, we conducted a distributed experiment comparing arthropods in leaf rolls versus control leaves across 52 sites along an 11,790 km latitudinal gradient. We then probed the impact of short- versus long-term climatic impacts on roll use, by comparing the relative impact of conditions during the experiment versus average, baseline conditions at the site. Leaf shelters supported larger organisms and higher arthropod biomass and species diversity than non-rolled control leaves. However, the magnitude of the leaf rolls' effect differed between long- and short-term climate conditions, metrics (species richness, biomass, and body size), and trophic groups (predators vs. herbivores). The effect of leaf rolls on predator richness was influenced only by baseline climate, increasing in magnitude in regions experiencing increased long-term aridity, regardless of latitude, elevation, and weather during the experiment. This suggests that shelter use by predators may be innate, and thus, driven by natural selection. In contrast, the effect of leaf rolls on predator biomass and predator body size decreased with increasing temperature, and increased with increasing precipitation, respectively, during the experiment. The magnitude of shelter usage by herbivores increased with the abundance of predators and decreased with increasing temperature during the experiment. Taken together, these results highlight that leaf roll use may have both proximal and ultimate causes. Projected increases in climate variability and aridity are, therefore, likely to increase the importance of biotic refugia in mitigating the effects of climate change on species persistence.
Subject(s)
Arthropods , Animals , Biodiversity , Climate Change , Ecosystem , Plant LeavesABSTRACT
The construction of shelters on plants by arthropods might influence other organisms via changes in colonization, community richness, species composition, and functionality. Arthropods, including beetles, caterpillars, sawflies, spiders, and wasps often interact with host plants via the construction of shelters, building a variety of structures such as leaf ties, tents, rolls, and bags; leaf and stem galls, and hollowed out stems. Such constructs might have both an adaptive value in terms of protection (i.e., serve as shelters) but may also exert a strong influence on terrestrial community diversity in the engineered and neighboring hosts via colonization by secondary occupants. Although different traits of the host plant (e.g., physical, chemical, and architectural features) may affect the potential for ecosystem engineering by insects, such effects have been, to a certain degree, overlooked. Further analyses of how plant traits affect the occurrence of shelters may therefore enrich our understanding of the organizing principles of plant-based communities. This data set includes more than 1000 unique records of ecosystem engineering by arthropods, in the form of structures built on plants. All records have been published in the literature, and span both natural structures (91% of the records) and structures artificially created by researchers (9% of the records). The data were gathered between 1932 and 2021, across more than 50 countries and several ecosystems, ranging from polar to tropical zones. In addition to data on host plants and engineers, we aggregated data on the type of constructs and the identity of inquilines using these structures. This data set highlights the importance of these subtle structures for the organization of terrestrial arthropod communities, enabling hypotheses testing in ecological studies addressing ecosystem engineering and facilitation mediated by constructs. There are no copyright restrictions and please cite this paper when using the data in publications.
Subject(s)
Arthropods , Animals , Biodiversity , Ecosystem , Insecta , Plant Leaves , PlantsABSTRACT
Little data is available on the bleeding risk and outcomes of cancer patients with chronic thrombocytopenia who underwent cardiac catheterization. We sought to assess the safety of coronary angiography, percutaneous coronary intervention, and antiplatelet therapy in cancer patients with acute coronary syndrome (ACS) and chronic thrombocytopenia. We performed a retrospective study of patients with chronic thrombocytopenia who underwent cardiac catheterization for ACS between November 2009 and November 2015. Preprocedural platelet counts were classified into 3 groups: mild thrombocytopenia (50,000 to 100,000/µL), moderate thrombocytopenia (30,000 to 50,000/µL), and severe thrombocytopenia (<30,000/µL). Postprocedural bleeding complications and overall survival (OS) were recorded. A total of 98 patients were included. Mean platelet count on admission was 47.63 ± 29.85 K/µL. Severe thrombocytopenia was identified in 36 patients (36.7%), moderate thrombocytopenia in 20 patients (20.4%), and mild thrombocytopenia in 42 patients (42.9%). Aspirin therapy (alone or in combination with clopidogrel) was used in 66 patients (67.3%), whereas 27 patients (27.6%) were on dual antiplatelet therapy. One procedure-related retroperitoneal hematoma and 3 procedure-related small hematomas were identified. No cerebrovascular events related to the procedure or the antiplatelet therapy were noted. Moderate thrombocytopenia was associated with decreased OS, whereas aspirin, dual antiplatelet therapy, and statin use showed a trend of improved OS. In conclusion, we suggest that coronary angiography and percutaneous coronary intervention can be performed safely in cancer patients with chronic thrombocytopenia. Aspirin therapy and dual antiplatelet therapy should be considered in cancer patients with chronic thrombocytopenia and ACS.
Subject(s)
Acute Coronary Syndrome/complications , Acute Coronary Syndrome/therapy , Cardiac Catheterization , Neoplasms/complications , Platelet Aggregation Inhibitors/therapeutic use , Thrombocytopenia/complications , Acute Coronary Syndrome/mortality , Adult , Aged , Aged, 80 and over , Aspirin/therapeutic use , Chronic Disease , Clopidogrel/therapeutic use , Coloring Agents/therapeutic use , Coronary Angiography , Drug Therapy, Combination , Female , Heart Failure/mortality , Hematoma/chemically induced , Humans , Male , Middle Aged , Neoplasms/mortality , Percutaneous Coronary Intervention , Retrospective Studies , Severity of Illness Index , Texas/epidemiology , Thrombocytopenia/mortalityABSTRACT
South America is undergoing a rapid and large-scale conversion of natural habitats to cultivated land. Ecosystem services still remain important but their level and sustainability are not known. We quantified predation intensity in an Argentinian agricultural landscape containing remnants of the original chaco serrano forest using artificial sentinel prey. We sought to identify the main predators and the effect of landscape configuration and maize phenology on predation pressure by invertebrate and vertebrate predators in this landscape. The most common predators were chewing insects (50.4% predation events), birds (22.7%), and ants (17.5%). Overall predation rates in forest fragments (41.6% per day) were significantly higher than in the surrounding maize fields (21.5% per day). Invertebrate predation was higher inside and at the edge of forest fragments than within fields, and did not change with increasing distance from a fragment edge, indicating a lack of spillover from the native habitat remnants to the cultivated matrix at the local scale. Distance from a continuous forest had a positive impact on predation by invertebrates and a negative impact on vertebrate predation.
ABSTRACT
Human activities have led to global simplification of ecosystems, among which Neotropical dry forests are some of the most threatened. Habitat loss as well as edge effects may affect insect communities. Here, we analyzed insects sampled with pan traps in 9 landscapes (at 5 scales, in 100-500 m diameter circles) comprising cultivated fields and Chaco Serrano forests, at overall community and taxonomic order level. In total 7043 specimens and 456 species of hexapods were captured, with abundance and richness being directly related to forest cover at 500 m and higher at edges in comparison with forest interior. Community composition also varied with forest cover and edge/interior location. Different responses were detected among the 8 dominant orders. Collembola, Hemiptera, and Orthoptera richness and/or abundance were positively related to forest cover at the larger scale, while Thysanoptera abundance increased with forest cover only at the edge. Hymenoptera abundance and richness were negatively related to forest cover at 100 m. Coleoptera, Diptera, and Hymenoptera were more diverse and abundant at the forest edge. The generally negative influence of forest loss on insect communities could have functional consequences for both natural and cultivated systems, and highlights the relevance of forest conservation. Higher diversity at the edges could result from the simultaneous presence of forest and matrix species, although "resource mapping" might be involved for orders that were richer and more abundant at edges. Adjacent crops could benefit from forest proximity since natural enemies and pollinators are well represented in the orders showing positive edge effects.
Subject(s)
Forests , Insecta , Animals , ArgentinaABSTRACT
Edges have become prevailing habitats, mainly as a result of habitat fragmentation and agricultural expansion. The interchange of functionally relevant organisms like insects occurs through these edges and can influence ecosystem functioning in both crop and non-crop habitats. However, very few studies have focused on the directionality of insect movement through edges, and the role of crop and non-crop amount has been ignored. Using bi-directional flight interception traps we investigated interchange of herbivore, natural enemy, pollinator and detritivore insects between native forest fragments and soybean crops, simultaneously considering movement direction, forest cover in the landscape and crop phenology. In total, 52,173 specimens and 877 morphospecies were collected. We found that, within most functional and taxonomic groups, movement intensity was similar (richness and/or abundance) between directions, whereas a predominantly forest-to-crop movement characterized natural enemies. Insect movement was extensively affected by crop phenology, decreasing during crop senescence, and was enhanced by forest cover particularly at senescence. Mainly the same herbivore species moved to and from the forest, but different natural enemy species predominated in each direction. Finally, our analyses revealed greater forest contribution to natural enemy than to herbivore communities in the crop, fading with distance to the forest in both groups. By showing that larger amounts of forest lead to richer insect interchange, in both directions and in four functional groups, our study suggests that allocation to natural and cultivated habitats at landscape level could influence functioning of both systems. Moreover, natural enemies seemed to benefit more than pests from natural vegetation, with natural enemy spillover from forests likely contributing to pest control in soybean fields. Thus consequences of insect interchange seem to be mostly positive for the agroecosystem, although consequences for the natural system deserve further study.
Subject(s)
Crops, Agricultural/parasitology , Forests , Glycine max/parasitology , Insecta/physiology , Agriculture/methods , Animals , Argentina , Arthropods/physiology , Ecosystem , Geography , Herbivory/physiology , Host-Parasite Interactions , Movement , Pollination/physiology , Population Dynamics , Predatory Behavior/physiologyABSTRACT
Loss and fragmentation of natural ecosystems are widely recognized as the most important threats to biodiversity conservation, with Neotropical dry forests among the most endangered ecosystems. Area and edge effects are major factors in fragmented landscapes. Here, we examine area and edge effects and their interaction, on ensembles of arthropods associated to native vegetation in a fragmented Chaco Serrano forest. We analyzed family richness and community composition of herbivores, predators, and parasitoids on three native plant species in 12 fragments of varying size and at edge/interior positions. We also looked for indicator families by using Indicator Species Analysis. Loss of family richness with the reduction of forest fragment area was observed for the three functional groups, with similar magnitude. Herbivores were richer at the edges without interaction between edge and area effects, whereas predators were not affected by edge/interior position and parasitoid richness showed an interaction between area and position, with a steeper area slope at the edges. Family composition of herbivore, predator, and parasitoid assemblages was also affected by forest area and/or edge/interior situation. We found three indicator families for large remnants and five for edges. Our results support the key role of forest area for conservation of arthropods taxonomic and functional diversity in a highly threatened region, and emphasize the need to understand the interactions between area and edge effects on such diversity.
Subject(s)
Arthropods/physiology , Biodiversity , Ecosystem , Animals , Argentina , Feeding Behavior , ForestsABSTRACT
El tratamiento conservador es el de elección en el cáncer de mama en estadios iniciales. La irradiación parcial acelerada de la mama es una estrategia que permite tratar únicamente el lecho quirúrgico con 1-2 cm de margen, en contraposición al tratamiento clásico, que consiste en irradiar toda la mama. La reducción del volumen a irradiar nos permite aumentar la dosis/fracción administrada, acortando la duración total del tratamiento. El interés creciente por este esquema terapéutico ha motivado la realización de ensayos fase I-III, que evalúan esta modalidad terapéutica mediante diferentes técnicas: braquiterapia intersticial multicatéter, braquiterapia intracavitaria mediante balón, radioterapia externa conformada y radioterapia intraoperatoria. La braquiterapia mediante balón incluye MammoSite, Axxent y Contura, y dispositivos híbridos como SAVI y ClearPath. Este artículo revisa las diferentes técnicas, reflejando las ventajas e inconvenientes de cada una de ellas. Aunque estamos a la espera de los resultados a largo plazo de los ensayos fase III, parece evidente que la irradiación parcial acelerada de la mama tendrá un papel importante en el manejo de un grupo seleccionado de pacientes con cáncer de mama precoz
Breast conservation therapy is the procedure of choice of early-stage breast cancer. Accelerated partial breast irradiation is an approach that treats only the lumpectomy bed plus a 1-2 cm margin, rather than the whole breast. Because of the small volume of irradiation, a higher dose can be delivered, thus reducing the total length of treatment. Growing interest in accelerated partial breast irradiation has prompted the development of phase I-III clinical studies evaluating distinct techniques within this therapeutic modality; these techniques include multicatheter interstitial brachytherapy, balloon-catheter brachytherapy, conformal external beam radiation therapy, and intraoperative radiation therapy. Balloon-based brachytherapy approaches include MammoSite, Axxent and Contura electronic brachytherapy. Hybrid brachytherapy devices include SAVI and ClearPath. This article reviews the different techniques, identifying the weaknesses and strengths of each approach, and proposes a direction for future research and development. Although further follow-up and mature phase III data are needed, it seems evident that accelerated partial breast irradiation will play a role in the management of a selected group of patients with early-stage breast cancer
Subject(s)
Humans , Female , Adult , Middle Aged , Radiotherapy/instrumentation , Radiotherapy/methods , Radiotherapy , Breast Neoplasms/radiotherapy , Mammaplasty/instrumentation , Mammaplasty/methods , Mammaplasty , Brachytherapy/instrumentation , Brachytherapy/methods , Brachytherapy , Breast Neoplasms/physiopathology , Breast Neoplasms/surgery , Prostheses and ImplantsABSTRACT
AIM: To evaluate the resources and techniques used in the irradiation of patients with breast cancer after lumpectomy or mastectomy and the status of implementation of new techniques and therapeutic schedules in our country. BACKGROUND: The demand for cancer care has increased among the Spanish population, as long as cancer treatment innovations have proliferated. Radiation therapy in breast cancer has evolved exponentially in recent years with the implementation of three-dimensional conformal radiotherapy, intensity modulated radiotherapy, image guided radiotherapy and hypofractionation. MATERIAL AND METHODS: An original survey questionnaire was sent to institutions participating in the SEOR-Mama group (GEORM). In total, the standards of practice in 969 patients with breast cancer after surgery were evaluated. RESULTS: The response rate was 70% (28/40 centers). In 98.5% of cases 3D conformal treatment was used. All the institutions employed CT-based planning treatment. Boost was performed in 56.4% of patients: electrons in 59.8%, photons in 23.7% and HDR brachytherapy in 8.8%. Fractionation was standard in 93.1% of patients. Supine position was the most frequent. Only 3 centers used prone position. The common organs of risk delimited were: homolateral lung (80.8%) and heart (80.8%). In 84% histograms were used. An 80.8% of the centers used isocentric technique. In 62.5% asymmetric fields were employed. CTV was delimited in 46.2%, PTV in 65% and both in 38.5%. A 65% of the centers checked with portal films. IMRT and hypofractionation were used in 1% and in 5.5% respectively. CONCLUSION: In most of centers, 3D conformal treatment and CT-based planning treatment were used. IMRT and hypofractionation are currently poorly implemented in Spain.