Key-factor analysis of immature stages of Aedes scapularis (Diptera: Culicidae) populations in southeastern Brazil

2002 ◽  
Vol 92 (4) ◽  
pp. 271-277 ◽  
Author(s):  
C. Casanova ◽  
A.P. do Prado
Keyword(s):  
Larval Instar ◽  
Southeastern Brazil ◽  
Population Fluctuations ◽  
Mortality Factors ◽  
Breeding Sites ◽  
Final Population ◽  
Key Factor ◽  
Synchronous Development ◽  
Population Sizes ◽  
Key Factor Analysis

AbstractDevelopment times and mortality factors were investigated for populations of Aedes scapularis (Rondani) occurring in natural temporary ground pools in southeastern Brazil. Analysis of life tables by the key-factor method showed that mortality caused by desiccation of breeding sites was the principal factor accounting for fluctuations in population sizes throughout the study period. For cohorts that completed development, mortality attributed to predation by aquatic insects ranged from 68 to 96% and was the most important cause of death. In these cohorts, final population size was determined by the high mortality rates that occurred during the fourth larval instar and pupal stages; however, the key-factor best accounting for the population fluctuations was predation of fourth instar larvae. The short mean time of 7.1 days for synchronous development of the larvae and the lack of evidence of density-dependent mortality suggested that the A. scapularis populations were not strongly regulated and can attain relatively high densities.

scholarly journals Population dynamics of Saissetia oleae. II. Life-tables and key-factor analysis

2017 ◽  
Vol 8 ◽  
pp. 59 ◽  
Author(s):  
E. T. Kapatos ◽  
E.T. Stratopoulou
Keyword(s):  
Factor Analysis ◽  
Population Dynamics ◽  
Population Change ◽  
Life Tables ◽  
Population Fluctuations ◽  
Mortality Factors ◽  
Population System ◽  
Key Factor ◽  
Key Factor Analysis ◽  
Table Data

A series of life-tables for the population of Saisselia oleae (Oliv.) (Homoptera: Coccidae) during five yearly generations (1981-86) were constructed in Corfu. Key-factor analysis carried out on the life-table data indicated that mortality of young stages during summer, caused mainly by the high temperatures, and mortality during spring, caused mainly by predation, determine total population change within each generation. These two mortality factors are the predominant factors of the population dynamics of S. oleae determining population fluctuations. The other mortality factors of the population system of S. oleae were less important. Summer parasites and egg predators, in particular, do not play any significant role on the population dynamics of S. oleae.

A key-factor analysis of population fluctuations in Andraca bipunctata Walker (Lepidoptera: Bombycidae)

1979 ◽  
Vol 69 (1) ◽  
pp. 195-201 ◽  
Author(s):  
B. Banerjee
Keyword(s):  
Factor Analysis ◽  
Statistical Tests ◽  
Population Fluctuations ◽  
Female Mortality ◽  
Mortality Factors ◽  
Density Dependent ◽  
Key Factor ◽  
Key Factor Analysis ◽  
Insect Populations ◽  
Sampling Procedures

AbstractThe causes of fluctuation and stabilisation in a population of Andraca bipunctata Wlk. on tea in India were assessed over three years using the technique of key-factor analysis. Failure to produce the maximum complement of eggs, together with female mortality and adult migration, is shown to be the key-factor. Other mortality factors include non-viability of eggs and parasitism of the caterpillars by the tachinid Cylindromyia sp. Mortality of the female pupae tends to stabilise the population by compensating for losses due to the key-factor, but neither this nor any other mortality factors appear to be significantly density-dependent. The need for devising specialised sampling procedures and statistical tests for tropical insect populations is discussed.

scholarly journals Comparing sterile male releases and other methods for integrated control of the tiger mosquito in temperate and tropical climates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Léa Douchet ◽  
Marion Haramboure ◽  
Thierry Baldet ◽  
Gregory L’Ambert ◽  
David Damiens ◽  
...  
Keyword(s):  
Vector Control ◽  
Mosquito Species ◽  
Integrated Control ◽  
Mass Trapping ◽  
Southwest Indian Ocean ◽  
Breeding Sites ◽  
Key Factor ◽  
Trapping Methods ◽  
Combination Of Methods ◽  
Tropical Climates

AbstractThe expansion of mosquito species worldwide is creating a powerful network for the spread of arboviruses. In addition to the destruction of breeding sites (prevention) and mass trapping, methods based on the sterile insect technique (SIT), the autodissemination of pyriproxyfen (ADT), and a fusion of elements from both of these known as boosted SIT (BSIT), are being developed to meet the urgent need for effective vector control. However, the comparative potential of these methods has yet to be explored in different environments. This is needed to propose and integrate informed guidelines into sustainable mosquito management plans. We extended a weather-dependent model of Aedes albopictus population dynamics to assess the effectiveness of these different vector control methods, alone or in combination, in a tropical (Reunion island, southwest Indian Ocean) and a temperate (Montpellier area, southern France) climate. Our results confirm the potential efficiency of SIT in temperate climates when performed early in the year (mid-March for northern hemisphere). In such a climate, the timing of the vector control action was the key factor in its success. In tropical climates, the potential of the combination of methods becomes more relevant. BSIT and the combination of ADT with SIT were twice as effective compared to the use of SIT alone.

Diversity and distribution of assemblages of estuarine decapod larvae (Crustacea: Decapoda: Anomura, Brachyura) in tropical southeastern Brazil

Zootaxa ◽  
2011 ◽  
Vol 2758 (1) ◽  
pp. 26 ◽  
Author(s):  
R. A. MAGRIS ◽  
L. F. LOUREIRO FERNANDES
Keyword(s):  
Spatial Heterogeneity ◽  
Relative Abundance ◽  
Southeastern Brazil ◽  
Spatial Gradient ◽  
Estuarine System ◽  
Ecological Stability ◽  
Tropical Estuaries ◽  
Key Factor ◽  
Decapod Larvae

Decapod larvae assemblages were studied in the tropical estuaries off southeastern Brazil (Piraquê-açú and Piraquê-mirim rivers estuaries). A total of 32 taxa of decapod larvae were recorded. Brachyuran larvae dominated in Piraquê-açú estuary, with 62% of the relative abundance, and 49% in Piraquê-mirim estuary. Mean larvae concentrations ranged from 17.2 m -3 at Piraquê-mirim (August 2003) to 221.1 m -3 at Piraquê-açú (April 2003). The assemblage of larvae in both estuaries was diverse, especially at Piraquê-mirim, which showed higher ecological stability. The high spatial heterogeneity of the Piraquê-açú and Piraquê-mirim estuarine system resulted in the division of the assemblage into two well-defined groups (truly estuarine and euryhaline). Salinity spatial gradient was a key factor in the structure and distribution of larvae.

Key Factor Analysis to Assess Cormorant Depredation on Inland Fisheries in the UK

2007 ◽  
pp. 14-27 ◽  
Author(s):  
J. R. Britton ◽  
J. P. Harvey ◽  
I. G. Cowx ◽  
T. Holden ◽  
M. J. Feltham ◽  
...  
Keyword(s):  
Factor Analysis ◽  
Inland Fisheries ◽  
Key Factor ◽  
Key Factor Analysis ◽  
The Uk
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