scholarly journals Research on Prediction of Shanghai’s Population Development from 2008 to 2050

2009 ◽  
Vol 1 (3) ◽  
Author(s):  
Kepei Men ◽  
Ping Zhou ◽  
Jing Liu ◽  
Liangyu Jiang
Keyword(s):  
Population Development

scholarly journals Is High Whitefly Abundance on Cassava in Sub-Saharan Africa Driven by Biological Traits of a Specific, Cryptic Bemisia tabaci Species?

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 260
Author(s):  
Habibu Mugerwa ◽  
Peter Sseruwagi ◽  
John Colvin ◽  
Susan Seal
Keyword(s):  
Food Security ◽  
Bemisia Tabaci ◽  
Development Time ◽  
Adult Emergence ◽  
Sub Saharan Africa ◽  
Biological Traits ◽  
Population Development ◽  
Species Classification ◽  
First Instar ◽  
Sub Saharan

In East Africa, the prevalent Bemisia tabaci whiteflies on the food security crop cassava are classified as sub-Saharan Africa (SSA) species. Economically damaging cassava whitefly populations were associated with the SSA2 species in the 1990s, but more recently, it has been to SSA1 species. To investigate whether biological traits (number of first instar nymphs, emerged adults, proportion of females in progeny and development time) of the cassava whitefly species are significant drivers of the observed field abundance, our study determined the development of SSA1 sub-group (SG) 1 (5 populations), SG2 (5 populations), SG3 (1 population) and SSA2 (1 population) on cassava and eggplant under laboratory conditions. SSA1-(SG1-SG2) and SSA2 populations’ development traits were similar. Regardless of the host plant, SSA1-SG2 populations had the highest number of first instar nymphs (60.6 ± 3.4) and emerged adults (50.9 ± 3.6), followed by SSA1-SG1 (55.5 ± 3.2 and 44.6 ± 3.3), SSA2 (45.8 ± 5.7 and 32.6 ± 5.1) and the lowest were SSA1-SG3 (34.2 ± 6.1 and 32.0 ± 7.1) populations. SSA1-SG3 population had the shortest egg–adult emergence development time (26.7 days), followed by SSA1-SG1 (29.1 days), SSA1-SG2 (29.6 days) and SSA2 (32.2 days). Regardless of the whitefly population, development time was significantly shorter on eggplant (25.1 ± 0.9 days) than cassava (34.6 ± 1.0 days). These results support that SSA1-(SG1-SG2) and SSA2 B. tabaci can become highly abundant on cassava, with their species classification alone not correlating with observed abundance and prevalence.

Spring population development of cereal aphids on durum wheat in Lleida, NE of Spain

1989 ◽  
Vol 107 (1-5) ◽  
pp. 203-210 ◽  
Author(s):  
X. Pons ◽  
R. Albajes ◽  
J. Avilla ◽  
M. J. Sarasúa ◽  
M. Artigues ◽  
...  
Keyword(s):  
Durum Wheat ◽  
Cereal Aphids ◽  
Population Development

Population development of the invader ctenophore Mnemiopsis leidyi , in the Black Sea and in other seas of the Mediterranean basin

2001 ◽  
Vol 139 (3) ◽  
pp. 431-445 ◽  
Author(s):  
Shiganova T. ◽  
Mirzoyan Z. ◽  
Studenikina E. ◽  
Volovik S. ◽  
Siokou-Frangou I. ◽  
...  
Keyword(s):  
Black Sea ◽  
Mediterranean Basin ◽  
The Black Sea ◽  
Mnemiopsis Leidyi ◽  
Population Development ◽  
The Mediterranean ◽  
The Mediterranean Basin

scholarly journals Types of changes of population development of settlements in South Banat (Serbia)

2018 ◽  
Vol 98 (1) ◽  
pp. 91-120
Author(s):  
Danica Djurkin
Keyword(s):  
Rural Areas ◽  
Spatial Organization ◽  
Population Development ◽  
Socioeconomic Conditions ◽  
Rural Settlements ◽  
Demographic Situation ◽  
Selective Transformation ◽  
Socioeconomic Transformation ◽  
Urban And Rural Areas ◽  
Relative Change

The existing spatial organization and current demographic situation of settlements in South Banat are the result of the synchronized processes of industrialization, urbanization and deagrarization, which determined the selective transformation of urban and rural areas. The processes mentioned above led to the concentration of population in urban and suburban zones, municipal centers and functionally most developed rural settlements, but also to depopulation of their rural hinterland. The paper discusses changes in the spatial-demographic settlement organization and examines the socioeconomic conditions of settlements transformation. Changes in the population development of settlements were considered based on the analysis of the net relative change in the number of inhabitants in urban and rural settlements, for period from 1961 to 2011. In this way, four main types of settlements were determined: progressive, stagnant, regressive and dominantly regressive type. In order to show the correlation between demographic changes and socioeconomic transformation of settlements, the method of successive (alternating) coefficients was applied. By comparative analysis of these quantitative and qualitative indicators (types), with the application of geographical and historical-genetic methods, a clearer view of changes in the population development of settlements was made, which was the goal of the research.

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