Population growth of Brevipalpus lewisi McGregor (Acarina: Tenuipalpidae) on grapevines

1980 ◽  
Vol 31 (5) ◽  
pp. 957 ◽  
Author(s):  
GA Buchanan ◽  
M Bengston ◽  
EM Exley
Keyword(s):  
Relative Humidity ◽  
Population Growth ◽  
Field Study ◽  
Growth Potential ◽  
Seasonal Abundance ◽  
Population Increase ◽  
Leaf Fall ◽  
Maximum Value ◽  
Positive Population

In the Mildura district of Victoria, Brevipalpus lewisi McGregor is responsible for 'bunch mite' symptoms on grapevines. Age-specific life and fecundity tables, compiled in the laboratory, showed that B. lewisi is capable of positive population growth over a range of temperatures at relative humidity levels commonly encountered in the field. The maximum value of rm obtained in the laboratory was 0.04/day, at 28�C and 35 % relative humidity. A field study of the seasonal abundance and intra-vine distribution of B. lewisi showed that populations increased about 60-fold during a season. The rate of population increase during summer was similar to laboratory estimates of population growth potential. Although the mites were present solely at the base of canes early in the season, later all green parts of the plant became infested. Predation and loss associated with leaf fall reduced the numbers of mites overwintering. Populations were further reduced by removal of mites during pruning.

Piping Plover population increase after Hurricane Sandy mediated by immigration and reproductive output

The Condor ◽  
2020 ◽  
Author(s):  
Samantha G Robinson ◽  
Daniel Gibson ◽  
Thomas V Riecke ◽  
James D Fraser ◽  
Henrietta A Bellman ◽  
...  
Keyword(s):  
New York ◽  
Population Growth ◽  
Reproductive Output ◽  
Hurricane Sandy ◽  
Population Increase ◽  
Piping Plover ◽  
Habitat Creation ◽  
Fire Island ◽  
Large Scale Disturbance ◽  
Positive Population

Abstract Evaluating population-level responses to conservation action following large-scale disturbance can improve the efficacy of future habitat conservation measures. In October 2012, Hurricane Sandy storm surges cleared vegetation and opened inlets through the barrier islands, Fire Island and Westhampton Island, New York, creating Piping Plover (Charadrius melodus) habitat. Storm effects prompted an island-wide stabilization project, which had the potential to negatively affect novel Piping Plover habitat. Certain sections of Fire Island were designed to create and/or improve habitat (hereafter, restoration areas) to mitigate possible habitat loss or degradation. Since Piping Plovers in New York appear to be habitat-limited, we anticipated positive population growth following habitat creation. From 2013 to 2018, we captured and banded 152 adults and 353 chicks, and monitored 279 nests and 160 broods. We developed an integrated population model to assess demographic processes in response to hurricane created-habitat (2013–2018) and the creation of restoration areas (2015–2018). We observed positive population growth in 3 of 5 yr, and overall growth throughout the period (λ¯ = 1.13). Immigration and reproductive output were correlated with population growth (r = 0.92 [95% CI: 0.22 to 0.98] and 0.84 [95% CI: –0.47 to 0.95], respectively). Compared with the rest of the study area, restoration areas had higher chick survival, and lower nest survival and after second-year site fidelity. The result was population growth in restoration areas (λ¯= 1.14) similar to the whole study area. In the short term, restoration areas seemed to mimic natural Piping Plover habitat. Vegetation removal, an important process in renewing natural Piping Plover habitat, likely will be necessary to maintain habitat suitability. Efforts to increase immigration of new breeding adults into the system, and to improve reproductive output, primarily by habitat creation or maintenance, are likely to have the greatest local effect on population growth.

Life Table Evaluation of Chronic Exposure to a Pesticide

1981 ◽  
Vol 38 (5) ◽  
pp. 485-494 ◽  
Author(s):  
Richard E. Daniels ◽  
J. David Allan
Keyword(s):  
Population Growth ◽  
Life Table ◽  
Daphnia Pulex ◽  
Sublethal Effect ◽  
Intrinsic Rate ◽  
Growth Potential ◽  
Population Increase ◽  
Toxic Substances ◽  
Eurytemora Affinis

The copepod Eurytemora affinis and the cladoceran Daphnia pulex were cultured at sublethal concentrations of dieldrin to test the usefulness of the intrinsic rate of population increase, r, as a bioassay statistic. The 48-h LC50 for E. affinis was 23 μg/L, but population growth rate measured by the life table method was only 12% of its control value at 5 μg/L and was zero at 10 μg/L, indicating a substantial sublethal effect. In contrast, D. pulex had a higher EC50 (251 μg/L) and showed little impairment of population growth potential below 220 μg/L. We suggest that the cladoceran was less sensitive than the copepod in both short- and long-term tests because of its simpler life cycle and larger size at hatching. The life table estimate of r appears to be an ecologically realistic measure of sublethal stress and requires an equivalent or shorter time to conduct than conventional long-term tests.Key words: acute toxicity, chronic toxicity, life table, r, toxic substances, Daphnia pulex, Eurytemora affinis, pesticide, dieldrin

scholarly journals Toward a Dualistic Growth? Population Increase and Land-Use Change in Rome, Italy

Land ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 749
Author(s):  
Leonardo Bianchini ◽  
Gianluca Egidi ◽  
Ahmed Alhuseen ◽  
Adele Sateriano ◽  
Sirio Cividino ◽  
...  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Population Growth ◽  
Mediterranean Basin ◽  
Urban Expansion ◽  
Arable Land ◽  
Central Italy ◽  
Agricultural Landscapes ◽  
Population Increase ◽  
Per Capita

The spatial mismatch between population growth and settlement expansion is at the base of current models of urban growth. Empirical evidence is increasingly required to inform planning measures promoting urban containment in the context of a stable (or declining) population. In these regards, per-capita indicators of land-use change can be adopted with the aim at evaluating long-term sustainability of urbanization processes. The present study assesses spatial variations in per-capita indicators of land-use change in Rome, Central Italy, at five years (1949, 1974, 1999, 2008, and 2016) with the final objective of quantifying the mismatch between urban expansion and population growth. Originally specialized in agricultural productions, Rome’s metropolitan area is a paradigmatic example of dispersed urban expansion in the Mediterranean basin. By considering multiple land-use dynamics, per-capita indicators of landscape change delineated three distinctive waves of growth corresponding with urbanization, suburbanization, and a more mixed stage with counter-urbanization and re-urbanization impulses. By reflecting different socioeconomic contexts on a local scale, urban fabric and forests were identified as the ‘winner’ classes, expanding homogeneously over time at the expense of cropland. Agricultural landscapes experienced a more heterogeneous trend with arable land and pastures declining systematically and more fragmented land classes (e.g., vineyards and olive groves) displaying stable (or slightly increasing) trends. The continuous reduction of per-capita surface area of cropland that’s supports a reduced production base, which is now insufficient to satisfy the rising demand for fresh food at the metropolitan scale, indicates the unsustainability of the current development in Rome and more generally in the whole Mediterranean basin, a region specialized traditionally in (proximity) agricultural productions.

Plant Resistance in Some Modern Soybean Varieties May Favor Population Growth and Modify the Stylet Penetration of Bemisia tabaci (Hemiptera: Aleyrodidae)

2021 ◽  
Author(s):  
Mauricélia F Almeida ◽  
Clébson S Tavares ◽  
Euires O Araújo ◽  
Marcelo C Picanço ◽  
Eugênio E Oliveira ◽  
...  
Keyword(s):  
Population Growth ◽  
Bemisia Tabaci ◽  
Intrinsic Rate ◽  
Reproductive Rate ◽  
Genetically Engineered ◽  
Population Increase ◽  
Net Reproductive Rate ◽  
Bt Toxin ◽  
Demographic Performance

Abstract Complaints of severe damage by whiteflies in soybean fields containing genetically engineered (GE) varieties led us to investigate the role of transgenic soybean varieties expressing resistance to some insects (Cry1Ac Bt toxin) and to herbicide (glyphosate) on the population growth and feeding behavior of Bemisia tabaci (Gennadius) MEAM1 (Hemiptera: Aleyrodidae). In the laboratory, the whiteflies reared on the GE Bt soybeans had a net reproductive rate (R0) 100% higher and intrinsic rate of population increase (rm) 15% higher than those reared on non-GE soybeans. The increased demographic performance was associated with a higher lifetime fecundity. In electrical penetration graphs, the whiteflies reared on the GE soybeans had fewer probes and spent 50% less time before reaching the phloem phase from the beginning of the first successful probe, indicating a higher risk of transmission of whitefly-borne viruses. Data from Neotropical fields showed a higher population density of B. tabaci on two soybean varieties expressing glyphosate resistance and Cry1Ac Bt toxin. These results indicate that some GE soybean varieties expressing insect and herbicide resistances can be more susceptible to whiteflies than non-GE ones or those only expressing herbicide resistance. Most likely, these differences are related to varietal features that increase host-plant susceptibility to whiteflies. Appropriate pest management may be needed to deal with whiteflies in soybean fields, especially in warm regions, and breeders may want to consider the issue when developing new soybean varieties.

scholarly journals Impact of abiotic factors on build-up of citrus psylla, Diaphorina citri Kuwayama population in Punjab, India

2014 ◽  
Vol 6 (2) ◽  
pp. 371-376 ◽  
Author(s):  
Hijam S. Devi ◽  
D. R. Sharma
Keyword(s):  
Relative Humidity ◽  
Disease Transmission ◽  
Minimum Temperature ◽  
Abiotic Factors ◽  
Winter Season ◽  
Seasonal Abundance ◽  
Maximum Temperature ◽  
Weak Links ◽  
Diaphorina Citri ◽  
Citrus Psylla

Seasonal abundance of citrus psylla (Diaphorina citri) Kuwayama was studied on Kinnow mandarin under Punjab conditions during 2012 and 2013. Population of D. citri was present throughout the year but only adults found surviving during December and February. There was no nymphal population when maximum temperature was > 39°C or < 7°C. Two population peaks of nymphs wer e observed, first in April-May and second in August- September. Thereafter, there was abrupt decline in nymphal population during June and July during both the years when the weather conditions i.e. maximum, minimum temperature (°C), relative humidity (%), rainfall (m m) and sunshine (hrs) ranged from 24.4-44, 22.4-31.8, 25.5-100, 0-108.0 and 0-13.5, respectively. Highest peaks of adult were found during May followed by June. With the decrease in temperature from the end of September, the population of D. citri started to decrease and reached its lowest during winter season. Correlation analysis for both the years indicated that maximum and minimum temperature, sunshine and rainfall were positively correlated with nymphal, adult and mixed population but the effect of rainfall on adult population was non-significant, while relative humidity was negatively correlated. The study is useful to find out the weak links of psyllid populations in relation to abiotic factors and that could be exploited to curb its infestation and disease transmission.

scholarly journals Determinants of the development of the Mazowieckie Province in 2007-2016

2018 ◽  
Vol 4 (2) ◽  
pp. 65-74
Author(s):  
Łukasz Grzęda
Keyword(s):  
Population Growth ◽  
College Graduates ◽  
National Average ◽  
Gdp Per Capita ◽  
Demographic Situation ◽  
Factors Influencing ◽  
Central Statistical ◽  
Central Statistical Office ◽  
Per Capita ◽  
Positive Population

The article presents the results of the analysis of factors influencing the development of the Mazowieckie Province (Masovia) in the years 2007–2016. Data for the study were collected from the Central Statistical Office and Statistical Yearbooks of the Mazowieckie Province. The results indicate that the level of development of Masovia is considerably higher than of other provinces in the country. At the end of the analyzed period, in Masovia the GDP per capita was almost twice as high as the national average. Masovia held the highest share in Poland’s GDP (22%). Important factors positively affecting the development of Masovia are: positive population growth and improving demographic situation, and broad access to telecommunications. Additional factors of the dynamic Masovia’s development are: extensive transportation infrastructure (104.3 km per 100 km2) and high number of students (236.5 thousand) and college graduates (60.8 thousand) who constitute the future substantive resources of the province’s economy.

scholarly journals The Nigerian population: A treasure for national development or an unsurmountable national challenge

2021 ◽  
Vol 2 (1) ◽  
pp. 136-142
Author(s):  
Vitalis Jafla Pontianus ◽  
Oruonye E.D.
Keyword(s):  
Economic Growth ◽  
Human Capital ◽  
Population Growth ◽  
National Development ◽  
Developed Countries ◽  
Resource Scarcity ◽  
Population Increase ◽  
High Population ◽  
Major Player ◽  
The World

Nigeria is the most populous black nation in the world. It is equally one of the Less Developed Countries (LDCs) with very high population. Population growth is a very important element and a challenge in the development process in LDCs. The population of Nigeria is expected to continue to grow up to 239 million by 2025 and 440 million by 2050, thereby ranking it to 4th position among countries of the World with high population. This without doubt will place Nigeria in a position of major player in the global system, and more importantly in the African region. It is against this background that this study examines Nigeria’s population composition by poising the following questions; will Nigeria’s present and future population structure be a benefit or a burden? How can Nigeria’s relative share of working-age composition (15- 64) and dependents (under 15 and 65 and over) contribute to long term economic growth and development of the country? The findings of the study reveals that population growth is a critical factor in the development of any economy, providing workforce for production of goods and services to boost economic development and a critical determinant of the potentials of a country’s investment. The study findings also show that continuous population growth militates against economic growth through inducement of poverty, falling medical care/services and environmental degradation, worsen resource scarcity in areas where a large proportion of the population already relies on natural resource-based livelihoods. The study argued that population increase is not a problem in itself to any nation, and that there are some impeding factors associated with population growth such as corruption, inadequate planning, inappropriate implementation of development plans, poor budget/implementation and complacency in developing human capital. These are issues that the Nigerian state since independence have continued to battle with which has invariably made it a seemingly failed state. The study concludes that how much any country can benefit from its population size is dependent on the quality of human capital. Based on the findings, the study recommends economic diversification, government empowerment of Small and Medium scale Enterprises, paying attention to human capital development and target-oriented education.

scholarly journals Seasonal Abundance and Infestation of Fruit Fly on Cucumber

2021 ◽  
Vol 18 (2) ◽  
pp. 233-241
Author(s):  
S Nahid ◽  
MR Amin ◽  
MM Haque ◽  
SJ Suh
Keyword(s):  
Relative Humidity ◽  
Light Intensity ◽  
Meteorological Factors ◽  
Fruit Fly ◽  
Methyl Eugenol ◽  
Seasonal Abundance ◽  
Bactrocera Cucurbitae ◽  
Larval Population ◽  
Weather Parameters ◽  
Positive Light

Population dynamics and infestation of fruit fly, Bactrocera cucurbitae Coquillett (Diptera: Tephritidae) was monitored on cucumber, Cucumis sativus using methyl eugenol trap during summer and autumn in 2017 at Gazipur, Bangladesh. Relationship between the abundance of fruit fly and meteorological factors was also studied. The fruit fly showed significantly higher abundance in summer compared to autumn. The larval population per fruit was found higher in summer (24.9 fruit-1) than that in autumn (1.5 fruit-1). The daily mean temperature had significant positive, light intensity had insignificant positive, relative humidity had insignificant negative and rainfall had insignificant negative correlation with fruit fly abundance. The temperature, light intensity, relative humidity and rainfall individually contributed to fruit fly abundance of 14.1 %, 24.0 %, 0.8 % and 1.8 %, respectively. The combined effect of the weather parameters on fruit fly abundance was 40.7 % and the equations were insignificant. The fruit fly showed significantly lower level of infestation in methyl eugenol treated plots as compared to controls in both summer and autumn. SAARC J. Agri., 18(2): 233-241 (2020)

Abstract P266: The Association Of Recent Age-specific Growth Of The > 65 Years Population With Heart Disease Mortality In The United States, 2005-2017

Circulation ◽  
2020 ◽  
Vol 141 (Suppl_1) ◽  
Author(s):  
Stephen Sidney ◽  
Sadiya S Khan ◽  
Yariv Gerber ◽  
Donald M Lloyd-jones ◽  
Alan S Go ◽  
...  
Keyword(s):  
Heart Disease ◽  
Mortality Rate ◽  
Population Growth ◽  
Total Population ◽  
Age Groups ◽  
The United States ◽  
Population Increase ◽  
Age Group ◽  
Specific Population ◽  
Time Periods

Introduction: In 2011, the number of deaths with an underlying cause of heart disease (HD) reached its lowest level in 56 years. However, there has subsequently been a steady increase in the annual number of total HD deaths, owing to a rapid increase (23%) in the size of the population ≥65 years of age in the U.S. To understand these trends, we sought to characterize differences between 2005-2011 and 2011-2017 in population and mortality by age subgroups among those ≥65 years. Methods: We determined age-specific population size, HD mortality rate, and absolute number of HD deaths in the ≥65 age group for the time periods 2005-2011 and 2011-2017, as well as for the <65 years age group, using the CDC WONDER online data set. Results: Age-specific population growth was greatest among those 65-74 years between 2005-2011 and 2011-2017, representing 76% of the total population growth among those ≥65 years old in both time periods (Table) and 51% of the growth for the entire population from 2011-2017. From 2005-2011, decreases in the mortality rate of 20% or greater in each of the age subgroups (65-74, 75-84, 85+) resulted in a decline in the number of total HD deaths in each of the age groups in spite of substantial population increases in the 65-74 and 85+ age groups. However, subsequent changes in the age-specific mortality rate among those ≥65 years were lower than population increases from 2011-2017, resulting in an increased number of total HD deaths in all > 65 years age subgroups. This was most notable among those age 65-74 years in whom the 32% population increase with a 1.5% decline in the mortality rate resulted in a 30% increase in the number of HD deaths, representing 61.3% of the increase in number of HD deaths in the 65+ years age group and 53% of the increase of HD deaths in all age groups from 2011-2017. Conclusions: The rapid growth of the 65-74 years age group (baby boomers) accounts for most of the population growth in the ≥65 years age group and more than half the increase in both total population growth and the total number of HD deaths from 2011-2017.

scholarly journals Influence of Temperature on Age-Stage, Two-Sex Life Tables for a Minnesota-Acclimated Population of the Brown Marmorated Stink Bug (Halyomorpha halys)

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 108 ◽  
Author(s):  
Byju N. Govindan ◽  
William D. Hutchison
Keyword(s):  
Population Growth ◽  
Life Table ◽  
Growth Potential ◽  
Intrinsic Rate Of Increase ◽  
Halyomorpha Halys ◽  
Brown Marmorated Stink Bug ◽  
Stink Bug ◽  
Current Limit ◽  
Rate Of Increase ◽  
Survival And Reproduction

Temperature is a critical single factor influencing insect population dynamics, and is foundational for improving our understanding of the phenology of invasive species adapting to new agroecosystems or in the process of range expansion. An age-stage, two-sex life table was therefore developed to analyze fundamental demographic features such as development, survival, and reproduction of a Minnesota-acclimated population of the invasive brown marmorated stink bug (Halyomorpha halys), in the north central USA. All salient life history parameters were estimated to better understand the population growth potential of H. halys at the current limit of its northern range in North America. We examined the effect of selected constant temperatures on immature development and survival (15–39 °C), adult reproduction and longevity (17–36 °C) of H. halys in the laboratory. The Minnesota population developed faster and survived at higher rates relative to a population that had previously established in Pennsylvania, USA. Mean generation time for the Minnesota population was minimized at 30 °C, while survival and fecundity were maximized at 27 and 23 °C, respectively. Given these findings, we assessed the effect of temperature on the intrinsic rate of increase ( r m ), the life table parameter that integrates the effects of temperature on development, survival, and reproduction. A Ratkowsky model predicted r m was maximized (0.0899) at 27.5 °C. We discuss the implications of our findings for understanding population growth rates for H. halys in the context of a warming climate, and potential to emerge as a serious crop pest in the Midwest U.S. region.

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