scholarly journals Geographic pattern of morphological variation of the coconut mite, Aceria guerreronis Keifer (Acari: Eriophyidae), using multivariate morphometry

2009 ◽  
Vol 69 (3) ◽  
pp. 773-783 ◽  
Author(s):  
D. Navia ◽  
GJ. Moraes ◽  
RB. Querino
Keyword(s):  
Principal Component ◽  
Distribution Area ◽  
Invasion History ◽  
Geographic Pattern ◽  
Aceria Guerreronis ◽  
Morphometric Variation ◽  
Asian Populations ◽  
Coconut Mite ◽  
Lack Of Information ◽  
Pattern Of Variation

The coconut mite, Aceria guerreronis Keifer, has become one of the most important pests of coconut in the Americas and Africa and recently in Southeast Asia. Despite the great economic importance of this mite, there is a lack of information on its origin and invasion history that are important to guide the search of biological control agents as well as the adoption of quarantine procedures. This study evaluates morphometric variation among A. guerreronis populations throughout its occurrence area, relates this variation with historical sequence of records, looking for information on its biogeography. Samples of 27 populations from the Americas, Africa and Asia were analysed using Principal Component Analysis and Canonical Discriminant Analysis. Results showed significant morphometric variability of A. uerreronis throughout its distribution area, with a high variability among American populations and otherwise a high similarity among African and Asian populations. The geographic pattern of variation of mite populations observed supports the hypothesis that A. guerreronis originated in the Americas and was introduced into Africa and Asia. Some inferences related to taxonomy of Eriophyoidea mites were included.

Relation of geographic variation in the skull of Microtus pennsylvanicus to climate

1983 ◽  
Vol 61 (6) ◽  
pp. 1232-1241 ◽  
Author(s):  
Richard R. Snell ◽  
Kimberly M. Cunnison
Keyword(s):  
Low Temperature ◽  
Geographic Variation ◽  
Multiple Regression ◽  
Minimum Spanning Tree ◽  
Climatic Factors ◽  
Principal Component ◽  
Microtus Pennsylvanicus ◽  
Annual Number ◽  
Simple Correlation ◽  
Morphometric Variation

Analyses of geographic variation in the skull of meadow voles (Microtus pennsylvanicus) indicate that phenetic distances among samples are not related to geographic distance: a minimum spanning tree based on average taxonomic distance superimposed on a map of 38 localities provides no particular phenetic clustering of those samples geographically proximate. A multiple regression of phenetic component one (skull size) onto orthogonally rotated climatic factors explains much less morphometric variation (25.6%) than a simple correlation with recorded extreme low temperature (38.9%). Multiple regression of phenetic principal component two (interorbital width) onto the same climatic factors explains minimally more morphological variation (42.1%) than a simple correlation with mean annual number of days with frost (41.7%). Microtus pennsylvanicus shows a pattern of size variation that is the reverse of Bergmann's rule: these voles are large where it is warm and small where it is cold. Since small size reduces total energy expenditure, we predict that during times of extreme low temperature (i) smaller voles will be less energetically stressed than larger voles and (ii) large size will be actively selected against.

scholarly journals Coconut destiny after the invasion of Aceria guerreronis (Acari: Eriophyidae) in India*

Zoosymposia ◽  
2011 ◽  
Vol 6 (1) ◽  
pp. 160-169 ◽  
Author(s):  
M. A. HAQ
Keyword(s):  
Management Practices ◽  
Critical Assessment ◽  
Bakery Products ◽  
Aceria Guerreronis ◽  
Agricultural Income ◽  
Northern India ◽  
Coconut Mite ◽  
Farming Community ◽  
The People ◽  
Considerable Damage

The coconut mite, Aceria guerreronis Keifer, has emerged as a common menace to most of the coconut plantations in India. After its first upsurge in Kerala at the end of the 1990´s, the mite has spread to many states in southern and northern India, causing considerable damage. Coconut provides one third of the agricultural income in the regions in which it is grown and more than 10 million people are dependent on this cash crop directly or indirectly through coconut-based industries like coir, copra, oil, honey, furniture, handicrafts, beverages, bakery products and so on. The economic instability of the coconut farming community and the people employed in coconut-based industries rank the highest order. A critical assessment of the various problems created by A. guerreronis in the agricultural economy of India is presented in order to supplement data on crop loss through nut malformation, nut fall, loss in fibre and copra. Varietal differences in susceptibility of the plant and future strategies in terms of management practices for an early control of the mite are discussed, and suggestions for future activities to alleviate mite damage are presented.

scholarly journals Imprint of Climate Change on Pan-Arctic Marine Vegetation

2020 ◽  
Vol 7 ◽  
Author(s):  
Dorte Krause-Jensen ◽  
Philippe Archambault ◽  
Jorge Assis ◽  
Inka Bartsch ◽  
Kai Bischof ◽  
...  
Keyword(s):  
Time Series ◽  
Management Strategies ◽  
Open Water ◽  
The Arctic ◽  
Distribution Area ◽  
Arctic Ecosystems ◽  
Migration Rates ◽  
Lack Of Information ◽  
Distribution Limits ◽  
And Storage

The Arctic climate is changing rapidly. The warming and resultant longer open water periods suggest a potential for expansion of marine vegetation along the vast Arctic coastline. We compiled and reviewed the scattered time series on Arctic marine vegetation and explored trends for macroalgae and eelgrass (Zostera marina). We identified a total of 38 sites, distributed between Arctic coastal regions in Alaska, Canada, Greenland, Iceland, Norway/Svalbard, and Russia, having time series extending into the 21st Century. The majority of these exhibited increase in abundance, productivity or species richness, and/or expansion of geographical distribution limits, several time series showed no significant trend. Only four time series displayed a negative trend, largely due to urchin grazing or increased turbidity. Overall, the observations support with medium confidence (i.e., 5–8 in 10 chance of being correct, adopting the IPCC confidence scale) the prediction that macrophytes are expanding in the Arctic. Species distribution modeling was challenged by limited observations and lack of information on substrate, but suggested a current (2000–2017) potential pan-Arctic macroalgal distribution area of 820.000 km2 (145.000 km2 intertidal, 675.000 km2 subtidal), representing an increase of about 30% for subtidal- and 6% for intertidal macroalgae since 1940–1950, and associated polar migration rates averaging 18–23 km decade–1. Adjusting the potential macroalgal distribution area by the fraction of shores represented by cliffs halves the estimate (412,634 km2). Warming and reduced sea ice cover along the Arctic coastlines are expected to stimulate further expansion of marine vegetation from boreal latitudes. The changes likely affect the functioning of coastal Arctic ecosystems because of the vegetation’s roles as habitat, and for carbon and nutrient cycling and storage. We encourage a pan-Arctic science- and management agenda to incorporate marine vegetation into a coherent understanding of Arctic changes by quantifying distribution and status beyond the scattered studies now available to develop sustainable management strategies for these important ecosystems.

scholarly journals Structure of the Chemical and Genetic Diversity of the True Lavender over Its Natural Range

Plants ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1640
Author(s):  
Yolande Despinasse ◽  
Sandrine Moja ◽  
Catherine Soler ◽  
Frédéric Jullien ◽  
Bernard Pasquier ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Environmental Variability ◽  
Principal Component ◽  
Common Garden ◽  
Distribution Area ◽  
Cultivated Plants ◽  
Native Range ◽  
Massif Central ◽  
Multiple Datasets ◽  
Natural Range

The true lavender Lavandula angustifolia Miller is a Mediterranean aromatic shrub widely cultivated for its high quality essential oil used in perfumery and phytotherapy. Despite its economic importance, the intra-specific diversity among wild, non-cultivated plants remains poorly understood. We analyzed the structure of the chemical and genetic diversity of plants from 14 sites sampled over the entire native range of the true lavender. Volatile organic compounds of inflorescences were analyzed using gas chromatography coupled to mass spectrometry. Genotyping was performed with fingerprinting genetic markers. To limit the influence of environmental variability on chemical composition, plants were grown in the same conditions in a common garden. Without prior knowledge, discriminant analysis of principal component identified unambiguously four distinct chemotypes among three genetic populations. Co-inertia analysis and supervised analysis which integrated multiple datasets indicated a strong congruency between chemical and genetic patterns. Two distinct genetic units were located at the edge of the distribution area in the south of Italy and in the northeast of Spain, and were associated with two distinct chemotypes. Our results confirmed the existence of three genetically distinct entities, suggesting speciation. All French populations and the Italian Piedmontese population were genetically homogeneous but separated in two distinct chemotypes. The dominant chemotype was present in the center of the native range in southeastern France and was at the origin of the current most cultivated French varieties. Its main compounds were linalyl acetate, linalool, and caryophyllene oxide. The second French chemotype was found in south of Massif Central and presented high abundance of valuable linalyl and lavandulyl acetates. Linalool, eucalyptol, β-caryophyllene, borneol, camphor, and cis-sabinene-hydrate were significantly associated with southern latitudes and their role would be worth exploring.

scholarly journals Developing a deprivation index to study geographical health inequalities in Ecuador

2019 ◽  
Vol 53 ◽  
pp. 97
Author(s):  
Andrés Peralta ◽  
Verónica Espinel-Flores ◽  
Mercè Gotsens ◽  
Glòria Pérez ◽  
Joan Benach ◽  
...  
Keyword(s):  
Health Inequalities ◽  
Principal Component ◽  
Positive Association ◽  
Well Being ◽  
Deprivation Index ◽  
Population Census ◽  
Subjective Well Being ◽  
Poisson Regression Model ◽  
Geographic Pattern ◽  
Standardised Mortality Ratios

OBJECTIVES: To develop a deprivation index to study health inequalities in 221 areas of Ecuador, to describe the pattern of deprivation in Ecuador, and to explore the applications of the index to study health inequalities by analysing the association between deprivation and mortality in the study areas. METHODS: We performed principal component analyses of available indicators of the 221 cantons of Ecuador. A set of 41 sociodemographic, social capital, and subjective well-being variables were obtained from the 2010 National Population Census and the National Living Conditions Survey 2013–2014. To explore the application of the index in public health, the association between the index and standardised mortality ratios was estimated through a Poisson regression model. RESULTS: The final index was constructed with 17 indicators. The first component explained 51.8% of the total variance of the data. A geographic pattern and a positive association of the index with the standardised mortality ratios of the cantons were observed in both men and women. CONCLUSIONS: We constructed a deprivation index that can identify disadvantaged areas in Ecuador. This index could be a valuable tool for the detection of vulnerabilised populations and the development of interventions and policies adapted to local needs.

scholarly journals Morphological Variability of Pterocarpus erinaceus Poir. in Togo

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Benziwa N. Johnson ◽  
Marie Luce A. Quashie ◽  
Kossi Adjonou ◽  
Kossi N. Segla ◽  
Adzo D. Kokutse ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Morphological Variability ◽  
Principal Component ◽  
West African ◽  
Distribution Area ◽  
Terminal Leaflet ◽  
Forest Species ◽  
Morphological Descriptors ◽  
Pterocarpus Erinaceus ◽  
Relevant Variables

Pterocarpus erinaceus Poir. (Fabaceae), also called Vène or West African rosewood, is a multipurpose endemic forest species of Sahelo-Sudanian and Sudano-Guinean savannas and forests of West Africa. In Togo, the species is overexploited, which dangerously hinders its survival. The need and emergency of restoring declining stands, using seeds, or propagating material suggests an assessment of its morphological variability. The purpose of this study is to identify the discriminating morphological descriptors, allowing us to describe and also to characterize the species. Five provenances distributed over the whole geographical distribution area in Togo were evaluated for leaf (7 descriptors), fruit (4 descriptors), and seed (4 descriptors) traits. The coefficient of variation (CV) and the principal component analysis (PCA) are used to assess the variability among tree populations. Results show that the discriminating morphological descriptors for P. erinaceus in Togo are the width of the leaf and the terminal leaflet, the length and the width of the fruit, and length and the weight of the seed. These six main relevant variables allow us to discriminate three morphological groups of P. erinaceus population.

scholarly journals Morphological and molecular identification of hairtail (Trichiurus spp.) caught in Pangandaran Waters

2020 ◽  
Vol 147 ◽  
pp. 02021
Author(s):  
Tia Aprianti Lestari ◽  
Murwantoko Murwantoko ◽  
Eko Setyobudi
Keyword(s):  
Principal Component Analysis ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Molecular Identification ◽  
Principal Component ◽  
Component Analysis ◽  
Rrna Gene ◽  
Morphometric Variation ◽  
Dorsal Fin ◽  
Fish Samples

This study aimed to identify the species of hairtail caught in Pengandaran waters based on morphological, meristic character and molecular approach. In total 135 fish samples were collected from Pangandaran Waters, during March-April 2017. Each sample was identified, measured on 22 morphometric and 4 meristic characters, then analyzed using Principal Component Analysis (PCA). Molecular identification was conducted by sequenced of 16S rRNA gene. The result of the research showed that hairtail characterized by III spines and 125-140 soft rays of dorsal fin (D.III, 125-140), the anal fin situated below 38th to 41th of dorsal-fin soft ray, I spine and 10 soft rays of pectoral fin (P.I.10), and I spine and 91 to 112 spinules of anal fin (A.I.91-112). Based on the morphological identification, the hairtail was belonged to Trichiurus lepturus. Principal Component Analysis showing the morphometric variation was presented in the caudal peduncle length. Molecular analysis of mitochondrial DNA of the partial 16S rRNA gene confirmed the hairtail as T. lepturus with similarity 98-99% based on previously published data. Phylogenetic analysis showed that T. lepturus from Pangandaran were closely similar to related species caught from the Southern Coast of Yogyakarta Special Territory (Indian Ocean) and Hainan China (Pacific Ocean).

Clinal Variation in the Common Brown Butterfly Heteronympha merope merope (Lepidoptera: Satyrinae)

1981 ◽  
Vol 29 (4) ◽  
pp. 631 ◽  
Author(s):  
K Pearse ◽  
ND Murray
Keyword(s):  
Indirect Evidence ◽  
Principal Component ◽  
Random Processes ◽  
Adaptive Significance ◽  
Clinal Variation ◽  
Wing Pattern ◽  
The Common ◽  
Interpopulation Variation ◽  
Pattern Of Variation ◽  
East West

Analyses of variation in seven wing pattern characters in H. merope merope females, from 22 sites throughout the range of the subspecies, show that the variation generally has a substantial genetic component. All characters exhibit significant interpopulation variation and one character (S) shows an obvious clinal pattern in a north-south direction. Variation in the total wing phenotype was examined by a multivariate principal component analysis. The first two principal components identified also show a clinal pattern: a north-south cline in component 1 and an east-west cline in component 2. Variation in component 1 is significantly associated with winter humidity and that in the second with yearly rainfall. Because the components cannot be identified simply as size, shape or colour vectors the possible adaptive significance of the results is not clear, although there is some indirect evidence that the pattern of variation is due to natural selection rather than random processes.

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