Seasonal succession and spatial–temporal distribution patterns of six larval cytospecies of the Simulium venustum/verecundum complex (Diptera: Simuliidae)

1993 ◽  
Vol 71 (1) ◽  
pp. 116-124 ◽  
Author(s):  
John W. McCreadie ◽  
Murray H. Colbo
Keyword(s):  
Spatial Distribution ◽  
Second Generation ◽  
Seasonal Succession ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Seasonal Occurrence ◽  
Generation Number ◽  
Avalon Peninsula ◽  
Ecological Profiles

The seasonal succession of S. venustum/verecundum cytospecies found in both sublacustrine and downstream habitats on the Avalon Peninsula, Newfoundland, was investigated. EFG/C venustum (= Simulium truncatum Lundström) appeared 1–5 weeks earlier than other cytospecies. ACD verecundum (= S. rostratum Lundström) and AA verecundum usually appeared later and remained in streams longer than EFG/C, AC(gb) venustum, CC2 venustum, or CC3 venustum. Seasonal occurrence of sympatric cytospecies often overlapped, though development was typically staggered and population peaks were asynchronous. EFG/C, and probably CC3, are univoltine in Newfoundland. AC(gb) may have a second generation at a few sites. CC2 has two or more generations per year in Newfoundland, though generation number varied among sites. ACD and AA are multivoltine. Proportionally more ACD and AA were found on vegetation than on rocks, whereas the reverse was true for EFG/C. As well, the density of a mixed ACD–AA population was usually higher on vegetation than on rocks. Cytospecies composition at sublacustrine sites was different from sites farther downstream. The results of the present investigation were also combined with those of a previous study on spatial distribution to construct spatial–temporal ecological profiles for four cytospecies (EFG/C, AC(gb), ACD, AA). Each cytospecies showed a distinct profile.

Spatial distribution patterns of larval cytotypes of the Simulium venustum/verecundum complex (Diptera: Simuliidae) on the Avalon Peninsula, Newfoundland: factors associated with occurrence

1991 ◽  
Vol 69 (10) ◽  
pp. 2651-2659 ◽  
Author(s):  
John W. McCreadie ◽  
Murray H. Colbo
Keyword(s):  
Spatial Distribution ◽  
Distribution Patterns ◽  
Geographic Area ◽  
Emergent Vegetation ◽  
Spatial Distribution Patterns ◽  
Factors Associated ◽  
Summer Generation ◽  
Small Streams ◽  
Almost All ◽  
Avalon Peninsula

Larval macrodistribution of cytotypes of the Simulium venustum/verecundum complex among 60 stream sites over a limited geographic area (Avalon Peninsula, Newfoundland) was investigated. Cytotypes included EFG/C, ACD, AA AC(gb), and CC2-3 (combined CC2 and CC3). Stream sites were classified into four types: outlets, trickles, small streams, and large streams. Factors that might explain patterns of occurrence (presence or absence) were examined using correlation, frequency, and cluster analyses. The data showed that larval EFG/C and ACD dominated outlet sites. The CC2-3 and AC(gb) cytotypes were most frequent at downstream sites. In downstream locations CC2-3 was found at almost all sites, whereas AC(gb) was most frequently found in cool, canopied streams, where the bottom consisted mainly of small stones and rubble. In the spring AA was most common at outlet sites. In the summer AA was most frequently found at outlets and trickles. The summer generation(s) of AA was associated with the distribution of trailing and emergent vegetation.

scholarly journals Spatial and Temporal Distribution of Ripe Muskmelon Fruit

HortScience ◽  
1997 ◽  
Vol 32 (7) ◽  
pp. 1178-1181 ◽  
Author(s):  
Yael Edan ◽  
James E. Simon
Keyword(s):  
Spatial Distribution ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Ripe Fruit ◽  
Chi Square ◽  
Spatial Distribution Patterns ◽  
Harvesting Systems ◽  
Chi Square Analysis ◽  
Best Fit ◽  
Over Time

The spatial distribution patterns of five melon cultivars (Cucumis melo L. var. reticulatus) were evaluated by measuring XY coordinates of ripe fruit locations in the field. Fruit ripeness distribution over time was also evaluated for three cultivars by measuring the number of ripe fruit, fruit mass, and location over time. Spatial distribution curves for distances between fruit clusters and individual fruit from cluster centroids varied between clusters and were derived for each cultivar from the best fit curves based on chi-square analysis from the two-dimensional spatial fruit distribution. These equations can be used for predicting actual fruit locations in the field. Ripeness distribution patterns indicated that, while the exact duration of the effective harvesting period is cultivar-dependent, the ripeness trend for each of the cultivars was similar. Spatial distribution patterns vary among melon cultivars and must be recognized in the design of automated harvesting systems.

Modeling spatial distribution of the unionid mussels and the core-satellite hypothesis

1998 ◽  
Vol 38 (7) ◽  
pp. 73-79 ◽  
Author(s):  
Hooi-Ling Lee ◽  
Donald DeAngelis ◽  
Hock-Lye Koh
Keyword(s):  
Spatial Distribution ◽  
Life Cycle ◽  
Success Rate ◽  
Distribution Patterns ◽  
Fish Host ◽  
Limited Movement ◽  
Unionid Mussels ◽  
Species Characteristics ◽  
Major Factors ◽  
Fish Hosts

This paper discusses the spatial distribution patterns of the various species of the Unionid mussels as functions of their respective life-cycle characteristics. Computer simulations identify two life-cycle characteristics as major factors governing the abundance of a species, namely the movement range of their fish hosts and the success rate of the parasitic larval glochidia in finding fish hosts. Core mussels species have fish hosts with large movement range to disperse the parasitic larval glochidia to achieve high levels of abundance. Species associated with fish host of limited movement range require high success rate of finding fish host to achieve at least an intermediate level of abundance. Species with low success rate of finding fish hosts coupled with fish hosts having limited movement range exhibit satellite species characteristics, namely rare in numbers and sparse in distributions.

scholarly journals Intra-Storm Pattern Recognition through Fuzzy Clustering

Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 57
Author(s):  
Konstantinos Vantas ◽  
Epaminondas Sidiropoulos
Keyword(s):  
Fuzzy Clustering ◽  
A Priori ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Rainfall Data ◽  
Rainfall Runoff ◽  
Domain Specific ◽  
Runoff Modeling ◽  
National Bank ◽  
Rainfall Patterns

The identification and recognition of temporal rainfall patterns is important and useful not only for climatological studies, but mainly for supporting rainfall–runoff modeling and water resources management. Clustering techniques applied to rainfall data provide meaningful ways for producing concise and inclusive pattern classifications. In this paper, a timeseries of rainfall data coming from the Greek National Bank of Hydrological and Meteorological Information are delineated to independent rainstorms and subjected to cluster analysis, in order to identify and extract representative patterns. The computational process is a custom-developed, domain-specific algorithm that produces temporal rainfall patterns using common characteristics from the data via fuzzy clustering in which (a) every storm may belong to more than one cluster, allowing for some equivocation in the data, (b) the number of the clusters is not assumed known a priori but is determined solely from the data and, finally, (c) intra-storm and seasonal temporal distribution patterns are produced. Traditional classification methods include prior empirical knowledge, while the proposed method is fully unsupervised, not presupposing any external elements and giving results superior to the former.

scholarly journals Spatio-temporal distribution patterns of Plutella xylostella (Lepidoptera: Plutellidae) in a fine-scale agricultural landscape based on geostatistical analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian-Yu Li ◽  
Yan-Ting Chen ◽  
Meng-Zhu Shi ◽  
Jian-Wei Li ◽  
Rui-Bin Xu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Plutella Xylostella ◽  
Agricultural Landscape ◽  
Seasonal Pattern ◽  
Distribution Patterns ◽  
Geostatistical Analysis ◽  
Distribution Model ◽  
Detailed Knowledge ◽  
Fine Scale ◽  
Spatio Temporal

AbstractA detailed knowledge on the spatial distribution of pests is crucial for predicting population outbreaks or developing control strategies and sustainable management plans. The diamondback moth, Plutella xylostella, is one of the most destructive pests of cruciferous crops worldwide. Despite the abundant research on the species’s ecology, little is known about the spatio-temporal pattern of P. xylostella in an agricultural landscape. Therefore, in this study, the spatial distribution of P. xylostella was characterized to assess the effect of landscape elements in a fine-scale agricultural landscape by geostatistical analysis. The P. xylostella adults captured by pheromone-baited traps showed a seasonal pattern of population fluctuation from October 2015 to September 2017, with a marked peak in spring, suggesting that mild temperatures, 15–25 °C, are favorable for P. xylostella. Geostatistics (GS) correlograms fitted with spherical and Gaussian models showed an aggregated distribution in 21 of the 47 cases interpolation contour maps. This result highlighted that spatial distribution of P. xylostella was not limited to the Brassica vegetable field, but presence was the highest there. Nevertheless, population aggregations also showed a seasonal variation associated with the growing stage of host plants. GS model analysis showed higher abundances in cruciferous fields than in any other patches of the landscape, indicating a strong host plant dependency. We demonstrate that Brassica vegetables distribution and growth stage, have dominant impacts on the spatial distribution of P. xylostella in a fine-scale landscape. This work clarified the spatio-temporal dynamic and distribution patterns of P. xylostella in an agricultural landscape, and the distribution model developed by geostatistical analysis can provide a scientific basis for precise targeting and localized control of P. xylostella.

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