The Role of Predators and Other Biotic Agents in Regulating the Population Density of Phytophagous Mites in Ontario Peach Orchards

1966 ◽  
Vol 98 (8) ◽  
pp. 808-820 ◽  
Author(s):  
W. L. Putman ◽  
D. H. C. Herne
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Tetranychus Urticae ◽  
Considerable Extent ◽  
Panonychus Ulmi ◽  
Apple Orchards ◽  
Rapid Population Growth ◽  
One Year ◽  
Heavy Mortality

AbstractMore than 40 species of insects and arachnids attack Panonychus ulmi (Koch), Tetranychus urticae Koch, T. canadensis (McGregor), Bryobia arborea Morgan and Anderson, or Aculus cornutus (Banks) in peach orchards of the Niagara Peninsula. The most effective predators attacking P. ulmi are Typhlodromus caudiglans Schuster, Haplothrips faurei Hood, Stethorus punctillum Weise, and Chrysopa spp. Peach orchards lack the predatory mirids characteristic of apple orchards. A condition, presumably disease, caused heavy mortality in one year. Endemic densities of P. ulmi are maintained in that state by predators, chiefly T. caudiglans, that subsist to a considerable extent on other sources of food, whereas epidemics of P. ulmi are reduced largely by other predators, chiefly H. faurei and S. punctillum, that increase in numbers by feeding on the mite during its period of rapid population growth but exert their greatest effect later in the season by destroying the winter eggs.

PREY PREFERENCES OF ADULT AND IMMATURE ZETZELLIA MALI EWING (ACARI: STIGMAEIDAE) AND TYPHLODROMUS CAUDIGLANS SCHUSTER (ACARI: PHYTOSEIIDAE)

1993 ◽  
Vol 125 (5) ◽  
pp. 967-969 ◽  
Author(s):  
David R. Clements ◽  
Rudolf Harmsen
Keyword(s):  
Biological Control ◽  
Potential Role ◽  
Panonychus Ulmi ◽  
Economic Damage ◽  
Apple Orchards ◽  
Effective Management ◽  
Phytoseiid Mites ◽  
Prey Preferences ◽  
Eriophyid Mites

Effective management of the interactions within the mite community is critical to biological control of economically damaging phytophagous mites such as Panonychus ulmi Koch (Tetranychidae) (Clements and Harmsen 1990). Although much is known about the potential role of phytoseiid mites in controlling P. ulmi (Dover et al. 1979), mites from at least seven other families may be present in apple orchards (Thistlewood 1991). Stigmaeid mites are predators which may play a beneficial role in biological control in conjunction with phytoseiids (Clements and Harmsen 1992). Eriophyid mites are phytophagous but seldom cause economic damage, and may compete with tetranychids and provide alternative food for predators of tetranychids (Croft and Hoying 1977).

Species Dominance of Tetranychus urticae and Panonychus ulmi (Acari: Tetranychidae) in Apple Orchards in the Southern part of Korea

2014 ◽  
Vol 53 (4) ◽  
pp. 415-425 ◽  
Author(s):  
Kyung-Hee Choi ◽  
◽  
Dong-Hyuk Lee ◽  
Soon-Won Lee ◽  
Changmann Yoon ◽  
...  
Keyword(s):  
Tetranychus Urticae ◽  
Panonychus Ulmi ◽  
Apple Orchards ◽  
Species Dominance

scholarly journals Immature culicidae (Diptera) collected from the Igapó lake located in the urban area of Londrina, Paraná, Brazil

2002 ◽  
Vol 45 (4) ◽  
pp. 465-471 ◽  
Author(s):  
José Lopes ◽  
João A. C. Zequi ◽  
Valdecir Nunes ◽  
Osmar de Oliveira ◽  
Bertolino P. de O. Neto ◽  
...  
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Urban Area ◽  
Culex Quinquefasciatus ◽  
Human Life ◽  
Abundant Species ◽  
Mosquito Population ◽  
One Year ◽  
And Control

The Igapó lake dam is located in an urban area in Londrina, Paraná, Brazil. A one year study of the Culicidae immature forms was conducted in this ecosystem. From a total of 962 collected larvae following genera were identified: Anopheles (59.36%), Culex (19.65%) Aedeomyia (19.23%) Aedes (1.50%), and Uranotaenia (0.10%). The 10 most abundant species were Anopheles strodei, Aedeomyia squamipennis, Culex (Melanoconium) spp., Culex mollis, Anopheles oswaldoi, Anopheles evansae, Culex coronator, Culex quinquefasciatus, Anopheles argyritarsis and Aedes terrens respectively. An. strodei prevailed with greater averages during July and September, showing a significant negative lineal correlation in relation to the rainfall. Ad. squamipennis showed a positive lineal correlation with the temperature with smaller population averages during June, August and September of 1997. Cx. (Melanoconium) spp. populations were constant throughout the year. High Culicidae population density could bring problems to quality of human life, thus strong measures to avoid and control of mosquito population growth in the lake are recommended.

PREDATION BY WASPS, BIRDS, AND MAMMALS ON HYPHANTRIA CUNEA

1972 ◽  
Vol 104 (10) ◽  
pp. 1581-1591 ◽  
Author(s):  
R. F. Morris
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Social Wasps ◽  
Rapid Population Growth ◽  
Hyphantria Cunea ◽  
Regulatory Influence

AbstractPredation by birds and social wasps (Vespula spp.) on larval colonies of Hyphantria cunea Drury was studied in both natural and artificial populations, and predation by mammals on overwintering pupae in the ground was studied in artificial populations. The species of predators are listed and some important differences in their habits of attack are described. Per cent predation by birds is directly related to the population density of H. cunea over a range of densities, but inversely related after density exceeds this range. When habitat and weather favor rapid population growth, H. cunea "escapes" from the population range in which predation exerts a regulatory influence.

scholarly journals Which Gridded Population Data Product Is Better? Evidences from Mainland Southeast Asia (MSEA)

2021 ◽  
Vol 10 (10) ◽  
pp. 681
Author(s):  
Xu Yin ◽  
Peng Li ◽  
Zhiming Feng ◽  
Yanzhao Yang ◽  
Zhen You ◽  
...  
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Southeast Asia ◽  
Anthropogenic Impacts ◽  
Local Population ◽  
Population Data ◽  
Rapid Population Growth ◽  
Ongoing Research ◽  
New Findings ◽  
Mainland Southeast Asia

The release of global gridded population datasets, including the Gridded Population of the World (GPW), Global Human Settlement Population Grid (GHS-POP), WorldPop, and LandScan, have greatly facilitated cross-comparison for ongoing research related to anthropogenic impacts. However, little attention is paid to the consistency and discrepancy of these gridded products in the regions with rapid changes in local population, e.g., Mainland Southeast Asia (MSEA), where the countries have experienced fast population growth since the 1950s. This awkward situation is unsurprisingly aggravated because of national scarce demographics and incomplete census counts, which further limits their appropriate usage. Thus, comparative analyses of them become the priority of their better application. Here, the consistency and discrepancy of the four common global gridded population datasets were cross-compared by combing the 2015 provincial population statistics (census and yearbooks) via error-comparison based statistical methods. The results showed that: (1) the LandScan performs the best both in spatial accuracy and estimated errors, then followed by the WorldPop, GHS-POP, and GPW in MSEA. (2) Provincial differences in estimated errors indicated that the LandScan better reveals the spatial pattern of population density in Thailand and Vietnam, while the WorldPop performs slightly better in Myanmar and Laos, and both fit well in Cambodia. (3) Substantial errors among the four gridded datasets normally occur in the provincial units with larger population density (over 610 persons/km2) and a rapid population growth rate (greater than 1.54%), respectively. The new findings in MSEA indicated that future usage of these datasets should pay attention to the estimated population in the areas characterized by high population density and rapid population growth.

scholarly journals Rapid Population Growth in Chinese Floodplains from 1990 to 2015

2018 ◽  
Vol 15 (8) ◽  
pp. 1602 ◽  
Author(s):  
Yongqiang Fang ◽  
Shiqiang Du ◽  
Paolo Scussolini ◽  
Jiahong Wen ◽  
Chunyang He ◽  
...  
Keyword(s):  
Climate Change ◽  
Population Density ◽  
Population Growth ◽  
Flood Risk ◽  
Socioeconomic Development ◽  
Total Population ◽  
Spatiotemporal Pattern ◽  
Rapid Population Growth ◽  
Over Time

Although China suffers from frequent and disastrous floods, the spatiotemporal pattern of its population living in the floodplain (PopF) is still unknown. This strongly limits our understanding of flood risk and the effectiveness of mitigation efforts. Here we present the first quantification of Chinese PopF and its dynamics, based on newly-available population datasets for years 1990, 2000, 2010, and 2015 and on a flood map. We found that the PopF in 2015 was 453.3 million and accounted for 33.0% of the total population, with a population density 3.6 times higher than outside floodplains. From 1990 to 2015, the PopF increased by 1.3% annually, overwhelmingly faster than elsewhere (0.5%). A rising proportion (from 53.2% in 1990 to 55.6% in 2015) of the PopF resided in flood zones deeper than 2 m. Moreover, the PopF is expected to increase rapidly in the coming decades. We also found the effect of flood memory on controlling PopF growth and its decay over time. These findings imply an exacerbating flood risk in China, which is concerning in the light of climate change and rapid socioeconomic development.

scholarly journals Population priorities: the challenge of continued rapid population growth

2009 ◽  
Vol 364 (1532) ◽  
pp. 2977-2984 ◽  
Author(s):  
Adair Turner
Keyword(s):  
Nineteenth Century ◽  
Population Density ◽  
Population Growth ◽  
Economic Performance ◽  
Developed Countries ◽  
Modern World ◽  
World Population ◽  
High Fertility ◽  
Rapid Population Growth ◽  
Per Capita

Rapid population growth continues in the least developed countries. The revisionist case that rapid population could be overcome by technology, that population density was advantageous, that capital shallowing is not a vital concern and that empirical investigations had not proved a correlation between high population growth and low per capita income was both empirically and theoretically flawed. In the modern world, population density does not play the role it did in nineteenth-century Europe and rates of growth in some of today's least developed nations are four times than those in nineteenth-century Europe, and without major accumulation of capital per capita , no major economy has or is likely to make the low- to middle-income transition. Though not sufficient, capital accumulation for growth is absolutely essential to economic growth. While there are good reasons for objecting to the enforced nature of the Chinese one-child policy, we should not underestimate the positive impact which that policy has almost certainly had and will have over the next several decades on Chinese economic performance. And a valid reticence about telling developing countries that they must contain fertility should not lead us to underestimate the severely adverse impact of high fertility rates on the economic performance and prospects of many countries in Africa and the Middle East.

scholarly journals Pronatalism: An Antithetical Value to Nigeria’s Reforms

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Chinyere C.P. Nnorom ◽  
Michael O.N. Kunnuji
Keyword(s):  
Population Growth ◽  
Population Size ◽  
Present State ◽  
Rapid Population Growth ◽  
Beliefs And Practices

The Nigerian state is heterogeneous. Despite some very sharp differences, certain values are common to all parts of the country. This paper focuses on one of such values with a view to assessing its role in bringing the Nigerian society to its present state. The value of attention is the value of pronatalism, which is here defined as beliefs and practices which underlie preference for many children. It is unfortunate that the ongoing reforms in Nigeria disregard the role of the value of pronatalism in the decay they seek to undo. A question is raised: What role has the constancy of the value of pronatalism and the resultant surge in population size played in getting the nation into the present political predicament? The paper appraises the stance of government on population matters over the years and notes that the co-incidence of the ills of rapid population growth and non-responsive governance has, more than any other factor, contributed to the present state of socio-political deformation. Based on this diagnosis, therefore, it is advocated that a negation of the value of pronatalism be factored into the reforms, if they must work.

scholarly journals Greenhouse and field evaluation of two biopesticides against Tetranychus urticae and Panonychus ulmi (Acari: Tetranychidae)

2012 ◽  
Vol 27 (4) ◽  
pp. 313-320 ◽  
Author(s):  
Dejan Marcic ◽  
Mirjana Prijovic ◽  
Tanja Drobnjakovic ◽  
Irena Medjo ◽  
Pantelija Peric ◽  
...  
Keyword(s):  
Population Density ◽  
Tetranychus Urticae ◽  
Chinese Herb ◽  
Field Evaluation ◽  
Panonychus Ulmi ◽  
Effective Control ◽  
Density Reduction ◽  
Botanical Pesticide ◽  
High Control ◽  
Two Spotted Spider Mite

The mycopesticide Naturalis (based on Beauveria bassiana strain ATCC 74040) and botanical pesticide Kingbo (based on oxymatrine, an alkaloid from Sophora flavescens, a traditional Chinese herb) were tested against the two-spotted spider mite (Tetranychus urticae) on greenhouse vegetables and the European red mite (Panonychus ulmi) on apples. These biopesticide products were applied twice at 5-day interval and concentrations of 0.1% and 0.2%, and their effectiveness was compared to abamectin-based products and the synthetic acaricides acrinathrin and spirodiclofen, applied once at their recommended rates. The mycopesticide Naturalis, applied at 0.1% concentration against T. urticae on cucumber, reduced mite population density by 85-86%, achieving 91-93% efficacy. In a trial on tomato, efficacy reached some 96%, while population density was reduced by 93%. In a field trial on apple, Naturalis demonstrated an increasing and long-lasting effectiveness against the summer population of P. ulmi of nearly 100%, and population reduction was achieved in assessments 30 days after the first treatment. Naturalis applied at a double rate achieved a somewhat better effect but only in the first trial. The botanical pesticide Kingbo, applied at 0.1% concentration, demonstrated very high control efficacy (?98%) and population density reduction (?96%) of T. urticae in both trials. A high and long-lasting effectiveness of this bioacaricide was also achieved in a trial on P. ulmi. Its concentration of 0.2% achieved similar effect. The results in these trials indicate that applications of the mycopesticide Naturalis and the botanical pesticide Kingbo can provide effective control of T. urticae on cucumber and tomato grown in greenhouses, as well as P. ulmi on apple.

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