scholarly journals Wing morphometrics reveals the migration patterns of Africanized honey bees in Northeast Brazil

Sociobiology ◽  
2018 ◽  
Vol 65 (4) ◽  
pp. 679
Author(s):  
Caroline Julio Moretti ◽  
Claudineia Pereira Costa ◽  
Tiago Maurício Francoy
Keyword(s):  
Geometric Morphometrics ◽  
Morphological Variation ◽  
Honey Bees ◽  
Rainy Season ◽  
Dry Season ◽  
Dispersion Pattern ◽  
Northeast Brazil ◽  
Africanized Honey Bees ◽  
Wing Morphometrics ◽  
Semi Arid

Climatic differences can directly affect the population structure of organisms. The Northeastern Brazilian covers an area of about 1.5 million square kilometres, in which the semi-arid part corresponds to approximately 60%. It is probably the most vulnerable region to climatic variations in Brazil. Here, we investigated the variability of Africanized honey bees in different localities from Northeast Brazil during the dry season and the influence of drought periods in morphological variation among populations. Analyses were carried out with data collected by traditional and geometric morphometrics of bees sampled during the dry season and showed a subtle morphological variation in agreement to the climatic pattern. Furthermore, once we added samples collected during the rainy season, we observed a change in its pattern, with a very different result from the same population sampled during drought periods. The geometric morphometrics results emphasized that samples collected during the rainy season in Mossoró would be more similar to bees from humid coastal areas. These results probably reflect the probable dispersion pattern of these bees between humid coastal and semi-arid areas.

The breeding season and diet of Arvicanthis in northern Nigeria

1989 ◽  
Vol 5 (4) ◽  
pp. 375-386 ◽  
Author(s):  
Safianu Rabiu ◽  
Martin Fisher
Keyword(s):  
Breeding Season ◽  
Food Supply ◽  
Rainy Season ◽  
Dry Season ◽  
Northern Nigeria ◽  
East African ◽  
African Savanna ◽  
Seasonal Differences ◽  
Sudan Savanna ◽  
Semi Arid

ABSTRACTThe breeding season and diet of the rat Arvicanthis was monitored from December 1983 to November 1985 in the semi-arid Sudan savanna at Kano, Nigeria, West Africa. Breeding began 1–2 months before the start of the rainy season and ceased at the beginning of the dry season. The diet of Arvicanthis was omnivorous, but with seasonal differences. Monocotyledons and dicotyledons predominated in the diet in the dry season, with seeds and insects increasing in the diet in the rainy season. The major differences between the ecology of Arvicanthis at Kano and on the East African savanna were that in East Africa the breeding season is longer and begins after the start of the rainy season. These and other dissimilarities between the biology of Arvicanthis in the two areas could be due to the effect of climatic differences on food supply and to the possible existence of different taxonomic groupings of Arvicanthis in the two regions.

scholarly journals A probabilistic model for predicting seasonal rainfall in semi-arid lands of northeast Brazil

2014 ◽  
Vol 364 ◽  
pp. 182-187
Author(s):  
B. B. da Silva ◽  
C. C. Braga ◽  
S. G. L. Montenegro ◽  
V. d. P. R. da Silva ◽  
L. M. M. de Oliveira ◽  
...  
Keyword(s):  
Probabilistic Model ◽  
Rainy Season ◽  
Arid Lands ◽  
Seasonal Rainfall ◽  
Northeast Brazil ◽  
Average Rainfall ◽  
Homogeneous Area ◽  
Semi Arid Region ◽  
Second Period ◽  
Semi Arid

Abstract. In most of the northeast region of Brazil rainfall is relatively low, presenting significant inter-annual fluctuations, especially when compared to rainfall in other areas of Brazil. Moreover, evaporative rates (like the ones found in the northeast semi-arid region) are too high, sometimes reaching over 2800 mm annually. Owing to such a climate character, very large areas in northeast Brazil are subjected to recurrent droughts. This paper presents a methodology for the prediction of seasonal rainfall in semi-arid lands of northeast Brazil. A total of 72 raingauge stations of Paraiba State, and 84 in Ceará State were employed, all of them distributed in three and seven homogeneous areas, respectively. A rainy season with different subdivisions was established for each homogeneous area. The zi proportions – the ratio between the cumulative rainfall of the first rainy season period and the rain that falls during the whole rainy season were made to fit the Beta probabilistic model used for calculating the second and eighth deciles and the probability of rainfall above the average rainfall for the second period of the rainy season. The performance of the prognostic model for individual stations of Paraíba State in the period 1996–2000 was evaluated. In the period 1996 to 2000, with rainfall above average, the error was less than 20 %. The methodology adopted proved very accurate for forecasting droughts in northeast Brazil.

scholarly journals Identification of Africanized honey bees through wing morphometrics: two fast and efficient procedures

Apidologie ◽  
2008 ◽  
Vol 39 (5) ◽  
pp. 488-494 ◽  
Author(s):  
Tiago Mauricio Francoy ◽  
Dieter Wittmann ◽  
Martin Drauschke ◽  
Stefan Müller ◽  
Volker Steinhage ◽  
...  
Keyword(s):  
Honey Bees ◽  
Africanized Honey Bees ◽  
Wing Morphometrics

scholarly journals Short-term variability of copepod abundance in Jurumirim Reservoir, São Paulo, Brazil

2001 ◽  
Vol 61 (4) ◽  
pp. 577-598 ◽  
Author(s):  
E. A. PANARELLI ◽  
M. G. NOGUEIRA ◽  
R. HENRY
Keyword(s):  
Rainy Season ◽  
Sampling Period ◽  
Abundant Species ◽  
Sao Paulo ◽  
Dry Season ◽  
Dispersion Pattern ◽  
São Paulo ◽  
Short Term ◽  
Copepod Abundance ◽  
Short Term Variability

Short-term variability in composition and abundance of copepod populations were studied during the dry (winter) and rainy (summer) seasons, at the dam region of Jurumirim Reservoir, São Paulo, Brazil. An intensive sampling program was carried out during 30 days in each period of the year. Samples and measurements were taken every other day at 0, 5, 10, 15, 20 and 25 m depths. The relationship between variability of the populations and some environmental factors was analyzed. The main species were: Argyrodiaptomus furcatus (Sars), Notodiaptomus iheringi (Wright), Mesocyclops longisetus (Thiébaud), Thermocyclops decipiens (Fischer), and T. minutus (Lowndes). Thermocyclops minutus was the most abundant species in dry season and its abundance varied significantly between sampling days. A large increase in abundance of calanoids occurred during the rainy season. This increase was correlated with higher temperature values. At that time, Notodiaptomus iheringi was dominant. This species showed significant short-term variations in abundance in both dry and rainy seasons. Significant variation in density of populations within the same sampling period might result from either the dispersion pattern of the populations or continuous substitution of the water masses. Significant correlation was observed between copepod abundance and temperature, especially for species of calanoids and there was also some correlations between densities of particular species of copepods and some phytoplankton taxa, mainly during the dry season. As for vertical distribution, most organisms were found between the surface and 15 m deep. During the rainy season, there was some evidence of the occurrence of spatial segregation between species of cyclopoids and calanoids, with the cyclopoids in a deeper position within the water column.

scholarly journals Vegetation indices as proxies for spatio-temporal variations in water availability in the Rio Santa valley (Peruvian Andes)

2021 ◽  
Author(s):  
Lorenz Hänchen ◽  
Cornelia Klein ◽  
Fabien Maussion ◽  
Wolfgang Gurgiser ◽  
Pierluigi Calanca ◽  
...  
Keyword(s):  
Water Availability ◽  
Rainy Season ◽  
Vegetation Indices ◽  
Growing Season ◽  
Dry Season ◽  
Season Length ◽  
Wet Season ◽  
Peruvian Andes ◽  
Spatio Temporal ◽  
Semi Arid

Abstract. In the semi-arid Peruvian Andes, the growing season is mostly determined by the timing of the onset and retreat of the wet season, to which annual crop yields are highly sensitive. Recently, local farmers in the Rio Santa basin (RSB) reported decreasing predictability of the onset of the rainy season and further challenges related to changes in rainfall characteristics. Previous studies based on time series of local rain gauges however, did not find any significant changes in either the timing or intensity of the wet season. Both in-situ and satellite rainfall data for the region lack the necessary spatial resolution to capture the highly variable rainfall distribution typical for complex terrain, and are often questionable in terms of quality and temporal consistency. To date, there remains considerable uncertainty in the RSB regarding hydrological changes over the last decades. In this study, we overcome this limitation by exploiting satellite-derived information on vegetation greenness to reveal a robust and highly resolved picture of recent changes in rainfall and vegetation phenology across the region: As the semi-arid climate causes water availability (i.e. precipitation) to be the key limiting factor for plant growth, patterns of precipitation occurrence and the seasonality of vegetation indices (VIs) are tightly coupled. Therefore, VIs can serve as an integrated proxy of rainfall. By combining MODIS Aqua and Terra VIs for 2000–2020 and several datasets of precipitation, we explore recent spatio-temporal changes in vegetation and water availability. Furthermore, we examine their links to El Niño Southern Oscillation (ENSO). While different rainfall datasets tend to be incoherent in the period of observation, we find significant greening over the majority of the RSB domain in VI data, particularly pronounced during the dry season (Austral winter). This indicates an overall increase of plant available water over time. The rainy season onset and consequently the start of the growing season (SOS) exhibits high inter-annual variability and dominates the growing season length (LOS). The end of the growing season (EOS) is significantly delayed in the analysis which matches the observed dry-season greening. By partitioning the results into periods of three stages of ENSO (neutral, Niño, Niña), we find an earlier SOS and an overall increased season length in years associated with El Niño. However, the appearance of Niño/Niña events during the analysed period cannot explain the observed greening and delayed EOS. While our study could not corroborate anecdotal evidence for recent changes in the SOS, we confirm that the SOS is highly variable and conclude that rainfed farming in the RSB would profit from future efforts being directed towards improving medium-range forecasts of the rainy season onset.

scholarly journals Acceptance rate of Africanized honey bee larvae in hives maintained in the shade and under full sunlight in Northeast Brazil

2016 ◽  
Vol 4 (2) ◽  
pp. 13-16
Author(s):  
Ricardo Gonçalves Santos ◽  
Daiana Da Silva Sombra ◽  
Herica Girlane Tertulino Domingos ◽  
Lionel Segui Gonçalves
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Acceptance Rate ◽  
Northeastern Brazil ◽  
Semiarid Region ◽  
Northeast Brazil ◽  
Africanized Honey Bees ◽  
Africanized Honey Bee ◽  
Full Sunlight ◽  
Semiarid Climate

In the Semiarid region of Northeast Brazil, adverse environmental conditions such as high radiation and temperature affect the balance of homeostasis of the colonies of Africanized honey bees (Apis mellifera L.). This research aimed to evaluate the rate of acceptance of Africanized honey bees larvae (Important stage of process of queen-rearing) in hives installed in the shade and under full sunlight in the semiarid climate of Northeastern Brazil. 10 colonies of honeybees (5 in the shade and 5 under full sunlight) were orphaned and prepared with young workers and food, having standardized biomass (equal population conditions) to receive frames containing 60-100 queen cell cups with larvae up to 24 hour-old. The acceptance percentage of transferred or grafted larvae to each colony was measured 72 hours after carrying out transfers and means were compared by the Student’s t-test at 5% probability. The colonies under shade conditions showed acceptance rate of 68.82 ± 17.03%, significantly higher (P = 0.0044) than the colonies subjected to direct sunlight with only 52.13 ± 16.29%. Thus, for the production of queens and royal jelly of Africanized honeybees in the semiarid climate of Northeast Brazil, it is strongly recommended the installation of apiaries in shady locations.Taxa de aceitação de larvas de abelhas africanizadas em colmeias mantidas em sombreamento e sob exposição solar direta no Nordeste BrasileiroNo Semiárido do Nordeste Brasileiro, as condições adversas do ambiente como alta radiação e temperatura afetam o equilíbrio da homeostase das colônias de abelhas africanizadas (Apis mellifera L.). Este trabalho objetivou avaliar a porcentagem de aceitação de larvas de abelhas africanizadas (etapa importante do processo de produção de rainha) em colmeias instaladas à sombra e sob radiação direta do sol na região semiárida do Nordeste Brasileiro. Para isso, 10 colônias (5 no sol e 5 na sombra) foram orfanadas e tiveram a biomassa padronizada para receber quadros portando de 60 a 100 cúpulas contendo larvas com até 24 horas de vida. O percentual de aceitação das larvas transferidas para cada colônia foi avaliado 72 horas após a realização das transferências e os dados foram comparadas pelo teste t-Student a 5% de probabilidade. As colônias sob condições de sombra apresentaram taxa de aceitação de 68,82 ± 17,03%, sendo significativamente maior (P = 0,0044) do que as colônias submetidas à radiação direta do sol, com apenas 52,13 ± 16,29%. Conclui-se que para a produção de rainhas e de geleia real de abelhas africanizadas no semiárido nordestino, torna-se extremamente recomendável a instalação de apiários em locais sombreados.

STUDI BIONOMIK VEKTOR MALARIA DI KECAMATAN KALIBAWANG, KULONPROGO

2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Sardjito Eko Windarso dkk
Keyword(s):  
Land Use ◽  
Malaria Vector ◽  
Rainy Season ◽  
Dry Season ◽  
Physical Factors ◽  
Mosquito Vector ◽  
Anopheles Species ◽  
Commercial Farming ◽  
Study Results ◽  
Dry And Rainy Seasons

The increasing of malaria cases in recent years at Kecamatan Kalibawang has been suspected correspond with the conversion of farming land-use which initiated in 1993. Four years after the natural vegetation in this area were changed become cocoa and coffee commercial farming estates, the number of malaria cases in 1997 rose more than six times, and in 2000 it reached 6085. This study were aimed to observe whether there were any differences in density and diversity of Anopheles as malaria vector between the cocoa and mix farming during dry and rainy seasons. The results of the study are useful for considering the appropriate methods, times and places for mosquito vector controlling. The study activities comprised of collecting Anopheles as well as identifying the species to determine the density and diversity of the malaria vector. Both activities were held four weeks in dry season and four weeks in rainy season. The mea-surement of physical factors such as temperature, humidity and rainfall were also conducted to support the study results. Four dusuns which meet the criteria and had the highest malaria cases were selected as study location. Descriptively, the results shows that the number of collected Anopheles in cocoa farming were higher compared with those in mix horticultural farming; and the number of Anopheles species identifi ed in cocoa farming were also more varied than those in the mix horticultural farming.Key words: bionomik vektor malaria, anopheles,

Seismic stratigraphy of a partially filled incised valley on a semi-arid continental shelf, Northeast Brazil

2021 ◽  
Vol 41 (2) ◽  
Author(s):  
Antonio Rodrigues Ximenes Neto ◽  
Paulo Roberto Silva Pessoa ◽  
Lidriana de Souza Pinheiro ◽  
Jáder Onofre de Morais
Keyword(s):  
Continental Shelf ◽  
Seismic Stratigraphy ◽  
Northeast Brazil ◽  
Incised Valley ◽  
Semi Arid
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