Life-history parameters and population dynamics of Ericaphis fimbriata (Hemiptera: Aphididae) on blueberry, Vaccinium corymbosum

2006 ◽  
Vol 138 (2) ◽  
pp. 205-217 ◽  
Author(s):  
D.A. Raworth ◽  
Daynika Schade
Keyword(s):  
Population Growth ◽  
Development Time ◽  
Adult Life ◽  
Vaccinium Corymbosum ◽  
Reproductive Period ◽  
Temperature Threshold ◽  
Leaf Type ◽  
Population Growth Rates ◽  
Mature Leaves ◽  
Young Leaves

AbstractDevelopment rate and age-specific fecundity and survival of Ericaphis fimbriata (Richards) virginoparae were determined during the spring on young leaves of blueberry, Vaccinium corymbosum L., as functions of temperature. The same traits were measured during the summer and the autumn on both young and mature leaves at 21.2 °C. The temperature threshold for development was 4.1 ± 0.5 °C (SE). For apterae, development time from birth to adult was 157.7 ± 5.9 day-degrees (dd). Proportional lengths of instars I–IV were 0.16, 0.14, 0.34, and 0.36, respectively. Adult life was 434.5 ± 17.5 dd and proportional lengths of the pre-reproductive, reproductive, and post-reproductive periods were 0.05, 0.74, and 0.21, respectively. Mean fecundity was 23.6 ± 1.0 nymphs per female. Mean survival was 602.9 ± 14.6 dd, and more than 80% of apterae survived the peak reproductive period. Alate fecundity was 16.5 ± 3.2 nymphs per female and alate survival was 460.9 ± 47.5 dd. Leaf type and season of measurement had significant effects on development time and fecundity: development time was 158.2 dd (+4.9 upper asymmetric SE) on young V. corymbosum ‘Duke’ leaves in the spring but 312.4 dd (–16.9 lower asymmetric SE) on mature ‘Bluecrop’ leaves, the dominant leaf type, from a commercial field in the summer. Fecundity for the respective leaf types and seasons was 16.7 (–1.6) and 1.4 (+0.5) nymphs per female. From summer to autumn, development time increased on young ‘Duke’ and ‘Bluecrop’ leaves but decreased on mature ‘Bluecrop’ leaves; fecundity decreased on young ‘Duke’ and ‘Bluecrop’ leaves but remained at low levels on mature ‘Bluecrop’ leaves. A simulation model showed that seasonal changes in development time and fecundity were capable of reducing population growth rates to near zero depending on aphid distribution with respect to young and mature leaves. The results support a combined bottom-up and top-down view of aphid population regulation and suggest that control efforts should focus on the spring, when the population growth rate is maximal.

The Effect of Temperature and Host Species on the Population Growth Potential of the Cowpea Aphid, Aphis Craccivora Koch (Homoptera: Aphididae).

1984 ◽  
Vol 32 (3) ◽  
pp. 345 ◽  
Author(s):  
GN Berg
Keyword(s):  
Population Growth ◽  
Host Plant ◽  
Host Species ◽  
Natural Increase ◽  
Reproductive Period ◽  
Aphis Craccivora ◽  
Growth Potential ◽  
Effect Of Temperature ◽  
Temperature Threshold ◽  
Aphis Craccivora Koch

Age-specific life and fecundity tables were compiled to determine the effect of temperature and host plant on the population growth potential of Aphis craccivora Koch. The intrinsic rate of natural increase (r*m) increased from zero at 5� to a maximum at 30�C, and then declined rapidly to zero at 35�C for aphids reared on all the host species tested. At 25�C aphids on Vicia faba showed a greater population growth potential than those on Capsella bursa-pastoris, followed by those on two Trifolium subterraneum cultivars and finally those on Medicago minima. An increase of temperature resulted in an earlier onset of mortality, irrespective of host-plant species. At higher temperatures the reproductive period began earlier and was shorter than at lower temperatures. The rate of reproduction appeared to be the key determinant in the aphid's population growth rate. The estimated lower temperature threshold of development of the aphid was 8.1�C.

Karakter Morfologi Daun Ubi Jalar Sebagai Bahan Pangan Suku Dani Distrik Kurulu Jayawijaya

Agrotek ◽  
2018 ◽  
Vol 2 (3) ◽  
Author(s):  
Antonius Suparno ◽  
Opalina Logo ◽  
Dwiana Wasgito Purnomo
Keyword(s):  
Sweet Potato ◽  
Leaf Morphology ◽  
Food Source ◽  
Staple Food ◽  
Sweet Potatoes ◽  
General Outline ◽  
Leaf Vein ◽  
Mature Leaves ◽  
Young Leaves ◽  
Tuber Roots

Sweet potato serves as a staple food for people in Jayawijaya. Many cultivars of sweet potatoes have been cultivated by Dani tribe in Kurulu as foot for their infant, child and adult as well as feeding especially for pigs. Base on the used of sweet potatoes as food source for infant and child, this study explored 10 different cultivars. As for the leaf morphology, it was indentified that the mature leaves have size around 15 � 18 cm. general outline of the leaf is reniform (40%), 60% have green colour leaf, 50% without leaf lobe, 60% of leaf lobes number is one, 70% of shape of central leaf lobe is toothed. Abazial leaf vein pigmentation have purple (40%), and petiole pigmentation is purple with green near leaf (60%), besides its tuber roots, sweet potatoes are also harvested for its shoots and green young leaves for vegetables.

scholarly journals The role of JrPPOs in the browning of walnut explants

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shugang Zhao ◽  
Hongxia Wang ◽  
Kai Liu ◽  
Linqing Li ◽  
Jinbing Yang ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Production Efficiency ◽  
Phenolic Content ◽  
Leaf Tissue ◽  
Limiting Factor ◽  
Mature Leaves ◽  
Survival Percentage ◽  
Highly Active ◽  
Young Leaves

Abstract Background Tissue culture is an effective method for the rapid breeding of seedlings and improving production efficiency, but explant browning is a key limiting factor of walnut tissue culture. Specifically, the polymerization of PPO-derived quinones that cause explant browning of walnut is not well understood. This study investigated explants of ‘Zanmei’ walnut shoot apices cultured in agar (A) or vermiculite (V) media, and the survival percentage, changes in phenolic content, POD and PPO activity, and JrPPO expression in explants were studied to determine the role of PPO in the browning of walnut explants. Results The results showed that the V media greatly reduced the death rate of explants, and 89.9 and 38.7% of the explants cultured in V media and A media survived, respectively. Compared with that of explants at 0 h, the PPO of explants cultured in A was highly active throughout the culture, but activity in those cultured in V remained low. The phenolic level of explants cultured in A increased significantly at 72 h but subsequently declined, and the content in the explants cultured in V increased to a high level only at 144 h. The POD in explants cultured in V showed high activity that did not cause browning. Gene expression assays showed that the expression of JrPPO1 was downregulated in explants cultured in both A and V. However, the expression of JrPPO2 was upregulated in explants cultured in A throughout the culture and upregulated in V at 144 h. JrPPO expression analyses in different tissues showed that JrPPO1 was highly expressed in stems, young leaves, mature leaves, catkins, pistils, and hulls, and JrPPO2 was highly expressed in mature leaves and pistils. Moreover, browning assays showed that both explants in A and leaf tissue exhibited high JrPPO2 activity. Conclusion The rapid increase in phenolic content caused the browning and death of explants. V media delayed the rapid accumulation of phenolic compounds in walnut explants in the short term, which significantly decreased explants mortality. The results suggest that JrPPO2 plays a key role in the oxidation of phenols in explants after branch injury.

scholarly journals Estimates of regional annual abundance and population growth rates of white sharks off central California

2021 ◽  
Vol 257 ◽  
pp. 109104
Author(s):  
Paul E. Kanive ◽  
Jay J. Rotella ◽  
Taylor K. Chapple ◽  
Scot D. Anderson ◽  
Timothy D. White ◽  
...  
Keyword(s):  
Population Growth ◽  
Growth Rates ◽  
Central California ◽  
Population Growth Rates

Demography of Xenosaurus platyceps (Squamata: Xenosauridae): a comparison between tropical and temperate populations

2008 ◽  
Vol 29 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Carissa Jones ◽  
Isaac Rojas-González ◽  
Julio Lemos-Espinal ◽  
Jaime Zúñiga-Vega
Keyword(s):  
Life History ◽  
Population Growth ◽  
Adult Mortality ◽  
Life History Strategies ◽  
Relative Importance ◽  
Theoretical Frameworks ◽  
Population Growth Rates ◽  
Relative Contribution ◽  
Two Populations ◽  
Average Fitness

Abstract There appears to be variation in life-history strategies even between populations of the same species. For ectothermic organisms such as lizards, it has been predicted that demographic and life-history traits should differ consistently between temperate and tropical populations. This study compares the demographic strategies of a temperate and a tropical population of the lizard Xenosaurus platyceps. Population growth rates in both types of environments indicated populations in numerical equilibrium. Of the two populations, we found that the temperate population experiences lower adult mortality. The relative importance (estimated as the relative contribution to population growth rate) of permanence and of the adult/reproductive size classes is higher in the temperate population. In contrast, the relative importance for average fitness of fecundity and growth is higher in the tropical population. These results are consistent with the theoretical frameworks about life-historical differences among tropical and temperate lizard populations.

scholarly journals Meteorological conditions, ozone concentration and leaf age affect gas exchange in Psidium guajava ‛Palumaʼ

Hoehnea ◽  
2017 ◽  
Vol 44 (2) ◽  
pp. 236-245 ◽  
Author(s):  
Juliana Moreno Pina ◽  
Sérgio Tadeu Meirelles ◽  
Regina Maria de Moraes
Keyword(s):  
Gas Exchange ◽  
Ozone Concentration ◽  
Leaf Age ◽  
Psidium Guajava ◽  
Meteorological Conditions ◽  
Gas Exchanges ◽  
Mature Leaves ◽  
Young Leaves ◽  
Entire Experiment ◽  
The City

ABSTRACT This study aimed to investigate the importance of leaf age, meteorological conditions and ozone concentration (O3) on gas exchange of Psidium guajava ‛Paluma'. Saplings were grown and exposed in standard conditions in the city of São Paulo, in six periods of three months with weekly measurements in young and mature leaves. Gas exchanges were higher in young leaves for almost the entire experiment. Mature leaves showed greater reduction in gas exchange. The multivariate analysis of biotic and abiotic variables indicated that vapor pressure deficit (VPD), O3 concentration and radiation were the main variables associated with gas exchange decrease in young leaves. In mature leaves the influence of VPD is lower, but the temperature importance is higher. Moreover, the opposition between assimilation and O3 is more evident in mature leaves, indicating their greater sensitivity to O3.

scholarly journals A New Bacterial Disease on Bluberry (Vaccinium Corymbosum) Caused by Pseudomonas Spp.

2013 ◽  
Vol 53 (1) ◽  
pp. 32-36 ◽  
Author(s):  
Monika Kałużna ◽  
Joanna Puławska ◽  
Beata Meszka
Keyword(s):  
Hypersensitivity Reaction ◽  
Pseudomonas Syringae ◽  
Vaccinium Corymbosum ◽  
Leaf Spot Disease ◽  
Bacterial Disease ◽  
Pseudomonas Spp ◽  
Leaf Spots ◽  
Pectolytic Activity ◽  
Young Leaves ◽  
First Time

Abstract In 2011, leaf spot disease was observed on the blueberry (Vaccinium corymbosum) cv. Nelson growing on a commercial field located in Central Poland. The disease symptoms could be seen as russet brown, irregular spots. The diameter of the spots was 0.3-0.5 cm, and the spots often coalesced. From these leaf spots, a fluorescent bacterium was repeatedly isolated in almost pure culture. Polymerase chain reaction (PCR) using primers Ps-for and Ps-rev, specific for Pseudomonas spp. confirmed that they belong to this genus. Based on LOPAT tests [levan production from sucrose (L), presence of oxidase (O), pectolytic activity on potato (P), the presence of arginine dihydrolase (A), hypersensitivity reaction on tobacco (T)], 6 isolates were classified to the LOPAT group Ib - group of Pseudomonas syringae subsp. savastanoi and Pseudomonas delphini, and one isolate to group Ia - P. syringae. All isolates caused a hypersensitivity reaction on tobacco plants, and symptoms similar to those under natural conditions, when young leaves of blueberry cv. Nelson were inoculated. Sequence analysis of 16S rRNA and rpoB genes showed the highest similarity of 6 studied strains to the species P. avellanae. Further taxonomic study is necessary to enable definitive classification of these isolates. It is the first time that a bacterial disease caused by the Pseudomonas spp. was observed in Poland.

Assessment of invasive rodent impacts on island avifauna: methods, limitations and the way forward

2015 ◽  
Vol 42 (2) ◽  
pp. 185 ◽  
Author(s):  
Lise Ruffino ◽  
Diane Zarzoso-Lacoste ◽  
Eric Vidal
Keyword(s):  
Population Growth ◽  
Population Level ◽  
Bird Conservation ◽  
Bird Population ◽  
Breeding Parameters ◽  
Population Growth Rates ◽  
Bird Populations ◽  
Field Evidence ◽  
Bird Breeding

Bird conservation is nowadays a strong driving force for prioritising rodent eradications, but robust quantitative estimates of impacts are needed to ensure cost-effectiveness of management operations. Here, we review the published literature to investigate on what methodological basis rodent effects on island bird communities have been evaluated for the past six decades. We then discuss the advantages and limitations of each category of methods for the detection and quantification of impacts, and end with some recommendations on how to strengthen current approaches and extend our knowledge on the mechanisms of impacts. Impact studies (152 studies considered) emphasised seabirds (67%), black rats (63%) and the Pacific Ocean (57%). Among the most commonly used methods to study rodent impacts on birds were the observation of dead eggs or empty nests while monitoring bird breeding success, and the analyses of rodent diets, which can both lead to misleading conclusions if the data are not supported by direct field evidence of rodent predation. Direct observations of rodent–bird interactions (19% of studies) are still poorly considered despite their potential to reveal cryptic behaviours and shed light on the mechanisms of impacts. Rodent effects on birds were most often measured as a change or difference in bird breeding parameters (74% of studies), while estimates of bird population growth rates (4%) are lacking. Based on the outcomes of this literature review, we highlight the need for collecting unbiased population-level estimates of rodent impacts, which are essential prerequisites for predicting bird population growth scenarios and prioritising their conservation needs. This could be achieved by a more systematic integration of long-term monitoring of bird populations into rodent management operations and modelling bird population dynamics. We also strongly recommend including various complementary methods in impact assessment strategies to unravel complex interactions between rodents and birds and avoid faulty evidence. Finally, more research should be devoted to a better understanding of the cases of non-impacts (i.e. long-term coexistence) and those impacts mediated by mechanisms other than predation and ecosystem-level processes.

scholarly journals ATIVIDADE ACARICIDA DE ÓLEOS ESSENCIAIS SOBRE Tetranychus ludeni (Zacher) (Acari: Tetranychidae) EM DUAS CULTIVARES DE ALGODOEIRO

Nativa ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 469
Author(s):  
Yasmin Bruna de Siqueira Bezerra ◽  
José Vargas de Oliveira ◽  
Taciana Keila dos Anjos Ramalho ◽  
Douglas Rafael e Silva Barbosa ◽  
Carlos Romero Ferreira de Oliveira ◽  
...  
Keyword(s):  
Population Growth ◽  
Essential Oils ◽  
Growth Rates ◽  
Ocimum Basilicum ◽  
Alternative Control ◽  
Population Growth Rates ◽  
Colored Cotton ◽  
Potential Alternative ◽  
Tetranychus Ludeni ◽  
Corymbia Citriodora

O presente trabalho teve como objetivo avaliar os efeitos repelentes e as taxas de crescimento populacional de óleos essenciais de Corymbia citriodora, Ocimum basilicum e Myracroduon urundeuva sobre o ácaro vermelho Tetranychus ludeni (Zacher) em algodoeiro de fibra colorida. Para o teste de repelência, óleos de Corymbia citriodora, Ocimum basilicum e Myracroduon urundeuva foram testados em diferentes concentrações sobre fêmeas adultas de T. ludeni, assim como para o teste de crescimento populacional, onde as cultivares foram tratadas com óleos essenciais.  O efeito repelente foi verificado para todos os óleos testados nas duas cultivares de algodão colorida. As taxas instantâneas de crescimento populacional para T. ludeni nas cultivares de algodoeiro BRS Verde e BRS Rubi foram todas positivas (ri> 0), indicando que a população está em estado ascendente, no entanto, a população cresceu a uma taxa menor quando comparada ao controle. Os óleos essenciais de C. citriodora, O. basilicum e M. urundeuva apresentam efeito acaricida e potencial controle alternativo de T. ludeni em algodoeiro de fibras coloridas sem causar danos ao algodoeiro.Palavras-chave: ácaro vermelho; algodão colorido; controle alternativo; taxa instantânea de crescimento; repelência. ACARICIDAL ACTIVITY OF ESSENTIAL OILS ON RED MITETetranychus ludeni (Zacher) (Acari: Tetranychidae) IN TWO COTTON CULTIVARS ABSTRACT: The objective of this work was to evaluate the repellent and population growth rates of essential oils of Corymbia citriodora, Ocimum basilicum and Myracroduon urundeuva on the red mite Tetranychus ludeni (Zacher) in cotton fiber. For the repellency test, oils of Corymbia citriodora, Ocimum basilicum and Myracroduon urundeuva were tested in different concentrations on adult females of T. ludeni, as well as for the population growth test, where the cultivars were treated with essential oils. The repellent effect was verified for all tested oils the two cultivars of colored cotton. The instant population growth rates for T. ludeni in the cultivars BRS Verde and BRS Rubi were all positive (ri> 0), indicating that the population is in an upward, however, the population grew at a lower rate when compared to the control. The essential oils of C. citriodora, O. basilicum and M. urundeuva have an acaricidal effect and potential alternative control of T. ludeni in cotton from colored fibers without causing damage to the cotton.Keywords: Red mite; colored cotton; essential oils; instant growth rate; repellency.

scholarly journals Antioxidant Activity Sonneratia caseolaris Leaves Extract at Different Maturity Stages

2020 ◽  
Vol 8 (3) ◽  
pp. 130
Author(s):  
Winarti Winarti ◽  
Boedi Setya Rahardja ◽  
Sudarno Sudarno
Keyword(s):  
Antioxidant Activity ◽  
Free Radical ◽  
Heart Attack ◽  
Total Content ◽  
Reactive Component ◽  
Mature Leaves ◽  
Maturity Stages ◽  
Sonneratia Caseolaris ◽  
Young Leaves ◽  
Ic50 Values

Free radical is a reactive component because it has one or more electrons. Free radical is very dangerous for our body because it can cause degenerative diseases, such as cancer, heart attack, and aging. Cancer and heart attack are one of the most killer disease. All we can do to decrease the free radical effect is consume antioxidant. S. caseolaris leaves has antioxidant activity, but it has known yet which stage of maturity is the best one for produce the highest antioxidant activity. This purpose of this research is knowing the influence between maturity and antioxidant activity at different maturity stages. This method of this research is experimental with Completely Randomized Design. The treatment in this research is vitamin C, fresh leaves in ethanol 96% extract, young leaves in ethanol 96% extract, and mature leaves in ethanol 96% extract. The main parameter of this research is IC50 values and the secondary parameters are total content of phytochemical in every extract. Data analysis using descriptive method with 4 treatments and five replications. The result of this research show that the maturity has influence in antioxidant activity. Inhibitory concentration 50 (IC50) values of shoot leaves extract, young leaves extract and mature leaves extract is 12.0013 ppm, 13.9915 ppm and 14.6613 ppm. All of them are called antioxidant which has very strong activities. The highest phytochemical compound is found on shoot leaves extract with ethanol 96% solvent.

Sign in / Sign up

Export Citation Format

Share Document