scholarly journals Spatio-temporal variation of predatory hoverflies (Diptera: Syrphidae) and their relationship with aphids in organic horticultural crops in La Plata, Buenos Aires

2020 ◽  
Vol 79 (4) ◽  
pp. 15-22
Author(s):  
María F. Diaz Lucas ◽  
Lilián M. Passareli ◽  
Noelia Maza ◽  
Daniel A. Aquino ◽  
Nancy M. Greco ◽  
...  
Keyword(s):  
Buenos Aires ◽  
Wild Plants ◽  
Immature Stages ◽  
Matricaria Chamomilla ◽  
Horticultural Crops ◽  
Direct Observations ◽  
Parasitism Rates ◽  
Diplazon Laetatorius ◽  
Wild Vegetation ◽  
Spatio Temporal

Population variations of predatory hoverflies in agroecosystems depend mainly on the resources that crops and wild vegetation provides them as well as death caused by natural enemies. We identified I) aphidophagous hoverfly species in lettuce and broccoli crops in Buenos Aires, II) the seasonal variations of the immature stages and their larval parasitism, and III) the wild plants, surrounding the crops, visited by adults. Fortnightly, 30 leaves were randomly selected in both crops during 2018-2019 and immature stages of syrphids and aphids per leaf were recorded. Adults were manually collected in patches of the wild plants (during 10 min of direct observations), and plants visited by adults were determined. The hoverflies were Allograpta exotica Wiedemann and Toxomerus duplicatus Wiedemann. Only A. exotica was recorded in crops. The dominant aphids were Myzus persicae (Sulzer) in lettuce and Brevycorine brassicae (L.) in broccoli. Parasitism rates ranged between 8 and 100% and the species were Diplazon laetatorius (Fabricius), in both crops, and Pachyneuron aff. nelsoni only in broccoli. Galinsoga parviflora Cav. and Matricaria chamomilla L. were the wild plants most often visited by hoverflies. This work provides basic information for the control of aphids by hoverflies in the framework of conservation biological control

Influence of emission inventory resolution on the modeled spatio-temporal distribution of air pollutants in Buenos Aires, Argentina, using WRF-Chem

2021 ◽  
pp. 118839
Author(s):  
Ana I. López-Noreña ◽  
Lucas Berná ◽  
Maria Florencia Tames ◽  
Emmanuel N. Millán ◽  
S. Enrique Puliafito ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Emission Inventory ◽  
Buenos Aires ◽  
Temporal Distribution ◽  
Spatio Temporal

Effects of Constant and Fluctuating Low Temperatures on the Development of Aedes aegypti (Diptera: Culicidae) from a Temperate Region

2019 ◽  
Vol 56 (6) ◽  
pp. 1661-1668 ◽  
Author(s):  
María Sol De Majo ◽  
Gabriela Zanotti ◽  
Raúl E Campos ◽  
Sylvia Fischer
Keyword(s):  
Aedes Aegypti ◽  
Low Temperatures ◽  
Buenos Aires ◽  
High Survival ◽  
Immature Stages ◽  
Temperate Region ◽  
Development Times ◽  
Average Survival ◽  
Geographical Regions ◽  
Aegypti Population

Abstract Most studies of the effects of low temperature on the development of immature stages of Aedes aegypti (L.) have been performed at constant temperatures in the laboratory, which may not accurately reflect the variable environmental conditions in the field. Thus, the aim of this study was to assess the effect of constant temperatures (CT) and fluctuating low temperatures (FT) on the fitness of Ae. aegypti of Buenos Aires, Argentina. Three CT treatments (12, 14, and 16°C) and three FT treatments (12, 14, and 16°C ± 4°C) were performed and then survival, development time, and size of adults analyzed for each treatment. The immature stages completed development in all the treatments, with an average survival of 88% at 16°C, 85% at 14°C, and 22% at 12°C, and showed no differences between the CT and FT treatments. Development times were similar between the CT and FT treatments at 16°C (average ± SD: 22.7 ± 2.0 d) and at 14°C (average ± SD: 30.5 ± 2.5 d), whereas at 12°C, they lasted longer under CT (average ± SD: 46.6 ± 5.1 d) than under FT (average ± SD: 37 ± 6.5 d). The sizes of the adults at 12 and 14°C were similar but larger than those at 16°C, and showed no differences between the CT and FT treatments. Compared to populations of other geographical regions assessed in previous studies, the shorter development times and the high survival at 14 and 16°C, and the ability to complete development at 12°C, a fact not previously reported, suggest that the Ae. aegypti population of Buenos Aires city has a higher tolerance to these conditions.

Strip-intercropping canola with annual alfalfa improves biological control of Plutella xylostella (L.) and crop yield

2017 ◽  
Vol 37 (03) ◽  
pp. 208-216 ◽  
Author(s):  
Pejman Tajmiri ◽  
Seyed Ali Asghar Fathi ◽  
Ali Golizadeh ◽  
Gadir Nouri-Ganbalani
Keyword(s):  
Species Diversity ◽  
Plutella Xylostella ◽  
Diversity Index ◽  
Cropping Systems ◽  
Diamondback Moth ◽  
Immature Stages ◽  
Spring Canola ◽  
Percent Parasitism ◽  
Parasitism Rates ◽  
Egg Density

AbstractThe population density of the diamondback moth (DBM),Plutella xylostella(L.), the species diversity of its predators, parasitism on eggs, larvae and pupae, and associated yield of canola were evaluated in experimental plots where spring canola was grown either as a monoculture or strip-intercropped with annual alfalfa in the ratio of 3C:3A, 6C:3A and 9C:3A over a 2-year period. The egg density was significantly higher in monoculture than in intercrops. The highest and lowest densities of larvae and pupae of DBM were recorded in monoculture (2.9–3.2 larvae per plant and 1.14–1.20 pupae per plant) and intercrop 3C:3A (0.7–0.6 larvae per plant and 0.34–0.29 pupae per plant), respectively. Shannon diversity index (H') for species composition of the predators of DBM immature stages was lower in monoculture than in intercrops, and was similar amongst the three intercrops. Moreover, the percent parasitism for eggs, larvae and pupae was higher in intercrops than in monoculture. The dry seed weight loss was higher in monocrop (37.6–40.1%) compared to 3C:3A (7.9–8.6%), 6C:3A (19.5–21.4%) and 9C:3A (21.6–25.4%). Our results indicate that intercropping canola with annual alfalfa, especially in the ratio 3C:3A, can increase the species diversity, parasitism rates of DBM immature stages, and enhance the yield of canola. The implications of these findings, in relation to integrated pest management (IPM) in canola cropping systems, are discussed.

scholarly journals Using Temporally Resolved Floral Resource Maps to Explain Bumblebee Colony Performance in Agricultural Landscapes

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1993
Author(s):  
Philipp W. Eckerter ◽  
Lars Albus ◽  
Sharumathi Natarajan ◽  
Matthias Albrecht ◽  
Lolita Ammann ◽  
...  
Keyword(s):  
Agricultural Land ◽  
Bombus Terrestris ◽  
Colony Growth ◽  
Agricultural Landscapes ◽  
Wild Plants ◽  
Floral Resources ◽  
Colony Development ◽  
Pollination Services ◽  
Spatio Temporal ◽  
Floral Resource

Wild bumblebees are key pollinators of crops and wild plants that rely on the continuous availability of floral resources. A better understanding of the spatio-temporal availability and use of floral food resources may help to promote bumblebees and their pollination services in agricultural landscapes. We placed colonies of Bombus terrestris L. in 24 agricultural landscapes with various degrees of floral resource availability and assessed different parameters of colony growth and fitness. We estimated pollen availability during different periods of colony development based on detailed information of the bumblebee pollen diet and the spatial distribution of the visited plant species. Total pollen availability did not significantly explain colony growth or fitness. However, when using habitat maps, the weight gain of colonies, the number of queen cells, and colony survival decreased with increasing distance from the forest. The better explanation of bumblebee performance by forest proximity than by (plant-inferred) pollen availability indicates that other functions of forests than pollen provision were important. The conservation of forests next to agricultural land might help to sustain high populations of these important wild pollinators and enhance their crop pollination services. Combining different mapping approaches might help to further disentangle complex relationships between B. terrestris and their environment in agricultural landscapes.

scholarly journals Unravelling respiratory syncytial virus outbreaks in Buenos Aires, Argentina: Molecular basis of the spatio-temporal transmission

Virology ◽  
2017 ◽  
Vol 508 ◽  
pp. 118-126 ◽  
Author(s):  
Gabriel Lihue Rojo ◽  
Stephanie Goya ◽  
Mariana Orellana ◽  
Andrea Sancilio ◽  
Alberto Rodriguez Perez ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Molecular Basis ◽  
Buenos Aires ◽  
Spatio Temporal ◽  
Syncytial Virus

Long-term spatio-temporal dynamics of the mosquito Aedes aegypti in temperate Argentina

2016 ◽  
Vol 107 (2) ◽  
pp. 225-233 ◽  
Author(s):  
S. Fischer ◽  
M.S. De Majo ◽  
L. Quiroga ◽  
M. Paez ◽  
N. Schweigmann
Keyword(s):  
Aedes Aegypti ◽  
Buenos Aires ◽  
Temporal Dynamics ◽  
Spatial Dynamics ◽  
Climatic Conditions ◽  
Buenos Aires Province ◽  
Southern Limit ◽  
Spatio Temporal ◽  
Lower Temperature

AbstractBuenos Aires city is located near the southern limit of the distribution of Aedes aegypti (Diptera: Culicidae). This study aimed to assess long-term variations in the abundance of Ae. aegypti in Buenos Aires in relation to changes in climatic conditions. Ae. aegypti weekly oviposition activity was analyzed and compared through nine warm seasons from 1998 to 2014, with 200 ovitraps placed across the whole extension of the city. The temporal and spatial dynamics of abundances were compared among seasons, and their relation with climatic variables were analyzed. Results showed a trend to higher peak abundances, a higher number of infested sites, and longer duration of the oviposition season through subsequent years, consistent with a long-term colonization process. In contrast, thermal favorability and rainfall pattern did not show a consistent trend of changes. The long-term increase in abundance, and the recently documented expansion of Ae. aegypti to colder areas of Buenos Aires province suggest that local populations might be adapting to lower temperature conditions. The steadily increasing abundances may have implications on the risk of dengue transmission.

Description of a new Corythucha Stål from Argentina (Hemiptera: Heteroptera: Tingidae), with a description of its life cycle

Zootaxa ◽  
2009 ◽  
Vol 2170 (1) ◽  
pp. 61-68 ◽  
Author(s):  
SARA I. MONTEMAYOR
Keyword(s):  
Life History ◽  
New Species ◽  
Quercus Robur ◽  
Buenos Aires ◽  
The Other ◽  
South American ◽  
Immature Stages ◽  
South American Species ◽  
History Of ◽  
A New Species

A new species of the genus Corythucha, C. bonaerensis n. sp., is described along with its egg and all immature stages. It was found in the province of Buenos Aires (Argentina) feeding on Quercus robur, its host plant. Comments on the life history of C. bonaerensis are provided together with photographs, and illustrations. The main differences with the other South American species, and other Corythucha species that feed on Quercus worldwide, are also discussed.

scholarly journals Spatial distribution and activities of the estuarine dolphin Sotalia guianensis (van Bénédén, 1864) (Cetacea, Delphinidae) in Pontal Bay, Ilhéus, Bahia, Brazil

2010 ◽  
Vol 10 (2) ◽  
pp. 67-73 ◽  
Author(s):  
Urânia Amaral dos Santos ◽  
Martin Roberto Alvarez ◽  
Ana Cristina Schilling ◽  
Gil Marcelo Reuss Strenzel ◽  
Yvonnick Le Pendu
Keyword(s):  
Spatial Distribution ◽  
Water Depth ◽  
High Tide ◽  
Temporal Distribution ◽  
Sotalia Guianensis ◽  
Direct Observations ◽  
Average Group ◽  
Spatio Temporal ◽  
Estuarine Dolphin ◽  
Average Group Size

We analyzed the influence of time, tide and water depth on the activity and spatial distribution of estuarine dolphins Sotalia guianensis in Pontal Bay, Ilhéus, Brazil. Direct observations were carried out at four fixed points from January to December of 2006. Estuarine dolphins were sighted in 11 out of 12 months and in 30% of 181 sampling periods. The average group size, which was 3.75 ± 1.59 (n = 64), did not vary significantly by month (Kruskal-Wallis, H = 10.6729; p = 0.3836). Infants and adults represented 18 and 82% of the individuals whose age we were able to determine, respectively. Estuarine dolphins were more frequently present than expected in areas deeper than 3 m (regression GLM, z = 3.773; p = 0.0002). The animals were more frequently observed between 7:00 and 8:00 AM and between 3:00 and 5:00 PM (X² = 83.815; p < 0.0001). Their presence in the bay tripled between the fourth hour of the flood and high tide, remaining elevated during the ebb tide (X² = 22.152; p = 0.02). The tide also influenced the animals' feeding and travelling direction, mainly toward the open see during the flood and to the back of the bay during others stages. Further studies are necessary to analyze the influence of the hydrographic characteristics of Pontal Bay on the spatio-temporal distribution of estuarine dolphins and their prey.

scholarly journals Acute bottlenecks to the survival of juvenile Pygoscelis penguins occur immediately after fledging

2020 ◽  
Vol 16 (12) ◽  
pp. 20200645
Author(s):  
Jefferson T. Hinke ◽  
George M. Watters ◽  
Christian S. Reiss ◽  
Jarrod A. Santora ◽  
M. Mercedes Santos
Keyword(s):  
Satellite Telemetry ◽  
Weight Of Evidence ◽  
Juvenile Mortality ◽  
Marine Predators ◽  
Tag Loss ◽  
Direct Observations ◽  
Order Of Magnitude ◽  
Juvenile Stages ◽  
Spatio Temporal ◽  
Free Ranging

Estimating when and where survival bottlenecks occur in free-ranging marine predators is critical for effective demographic monitoring and spatial planning. This is particularly relevant to juvenile stages of long-lived species for which direct observations of death are typically not possible. We used satellite telemetry data from fledgling Adélie, chinstrap and gentoo penguins near the Antarctic Peninsula to estimate the spatio-temporal scale of a bottleneck after fledging. Fledglings were tracked up to 106 days over distances of up to 2140 km. Cumulative losses of tags increased to 73% within 16 days of deployment, followed by an order-of-magnitude reduction in loss rates thereafter. The timing and location of tag losses were consistent with at-sea observations of penguin carcasses and bioenergetics simulations of mass loss to thresholds associated with low recruitment probability. A bootstrapping procedure is used to assess tag loss owing to death versus other factors. Results suggest insensitivity in the timing of the bottleneck and quantify plausible ranges of mortality rates within the bottleneck. The weight of evidence indicates that a survival bottleneck for fledgling penguins is acute, attributable to predation and starvation, and may account for at least 33% of juvenile mortality.

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