Non-Crop Host Sampling Yields Insights into Small-Scale Population Dynamics of Drosophila suzukii (Matsumura)

The large- and small-scale vortical motions produced by ‘delta tabs’ in a two-stream shear layer have been studied experimentally. An increase in mixing was observed when the base of the triangular shaped tab was affixed to the trailing edge of the splitter plate and the apex was pitched at some angle with respect to the flow axis. Such an arrangement produced a pair of counter-rotating streamwise vortices. Hot-wire measurements detailed the velocity, time-averaged vorticity (Ωx) and small-scale turbulence features in the three-dimensional space downstream of the tabs. The small-scale structures, whose scale corresponds to that of the peak in the dissipation spectrum, were identified and counted using the peak-valley-counting technique. The optimal pitch angle, θ, for a single tab and the optimal spanwise spacing, S, for a multiple tab array were identified. Since the goal was to increase mixing, the optimal tab configuration was determined from two properties of the flow field: (i) the large-scale motions with the maximum Ωx, and (ii) the largest number of small-scale motions in a given time period. The peak streamwise vorticity magnitude [mid ]Ωx−max[mid ] was found to have a unique relationship with the tab pitch angle. Furthermore, for all cases examined, the overall small-scale population was found to correlate directly with [mid ]Ωx−max[mid ]. Both quantities peaked at θ≈±45°. It is interesting to note that the peak magnitude of the corresponding circulation in the cross-sectional plane occurred for θ≈±90°. For an array of tabs, the two quantities also depended on the tab spacing. An array of contiguous tabs acted as a solid deflector producing the weakest streamwise vortices and the least small-scale population. For the measurement range covered, the optimal spacing was found to be S≈1.5 tab widths.

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Aquatic beetles of the alpine lakes: diversity, ecology and small-scale population genetics

Knowledge and Management of Aquatic Ecosystems ◽

10.1051/kmae/2011064 ◽

2011 ◽

pp. 10 ◽

Cited By ~ 7

Author(s):

Z. Čiamporová-Zaovičová ◽

F. Čiampor

Keyword(s):

Population Genetics ◽

Alpine Lakes ◽

Small Scale ◽

Aquatic Beetles ◽

Scale Population

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Population dynamics of spotted wing drosophila (Drosophila suzukii) in orchards in the Zagreb area

Pomologia Croatica ◽

10.33128/pc.23.3-4.2 ◽

2020 ◽

Vol 23 (3-4) ◽

pp. 91-102

Author(s):

Ivana Pajač Živković ◽

Irena Brlić Puškarić ◽

Darija Lemić

Keyword(s):

Invasive Species ◽

Population Dynamics ◽

Overlapping Generations ◽

Host Plants ◽

Climatic Conditions ◽

Spotted Wing Drosophila ◽

Drosophila Suzukii ◽

Research Population ◽

Zagreb Area ◽

The City

The invasive species Drosophila suzukii (Matsumura, 1931), the spotted wing drosophila, was first recorded in Croatia in 2010. Since then, it has spread on Croatian territory but its presence has not yet been confirmed in the City of Zagreb. In this research population dynamics of D. suzukii was investigated in three orchards in Zagreb (Maksimir, Jelenovac, Zelenjak) in the period from 20th of March to 27th of November 2017. Feeding traps with apple vinegar were used for catching D. suzukii. The flight began in the period from 27th of June to 11th of July and lasted until 27th of November. The total pest catches were 874 specimens (Jelenovac 187, Maksimir 232 and Zelenjak 455). From September to November there was a continuous flight and a large increase in the number of caught flies, suggesting the presence of more overlapping generations. Besides the host plants, the development of the pest in this area is also enabled by suitable climatic conditions. The present population in the City of Zagreb County poses a danger to fruit producers in the Zagreb County. The results of this research are a contribution to better understanding of the population and the spread of the pest in Croatia.

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Fine-scale population dynamics in a marine fish species inferred from dynamic state-space models

Journal of Animal Ecology ◽

10.1111/1365-2656.12678 ◽

2017 ◽

Vol 86 (4) ◽

pp. 888-898 ◽

Cited By ~ 6

Author(s):

Lauren A. Rogers ◽

Geir O. Storvik ◽

Halvor Knutsen ◽

Esben M. Olsen ◽

Nils C. Stenseth

Keyword(s):

Population Dynamics ◽

State Space ◽

Marine Fish ◽

Fish Species ◽

State Space Models ◽

Dynamic State ◽

Fine Scale ◽

Marine Fish Species ◽

Scale Population

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The Random Forest-Based Method of Fine-Resolution Population Spatialization by Using the International Space Station Nighttime Photography and Social Sensing Data

Remote Sensing ◽

10.3390/rs10101650 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1650 ◽

Cited By ~ 16

Author(s):

Kangning Li ◽

Yunhao Chen ◽

Ying Li

Keyword(s):

Random Forest ◽

International Space Station ◽

Population Distribution ◽

Space Station ◽

Small Scale ◽

International Space ◽

Point Of Interest ◽

Scale Population ◽

Fine Resolution ◽

Population Mapping

Despite the importance of high-resolution population distribution in urban planning, disaster prevention and response, region economic development, and improvement of urban habitant environment, traditional urban investigations mainly focused on large-scale population spatialization by using coarse-resolution nighttime light (NTL) while few efforts were made to fine-resolution population mapping. To address problems of generating small-scale population distribution, this paper proposed a method based on the Random Forest Regression model to spatialize a 25 m population from the International Space Station (ISS) photography and urban function zones generated from social sensing data—point-of-interest (POI). There were three main steps, namely HSL (hue saturation lightness) transformation and saturation calibration of ISS, generating functional-zone maps based on point-of-interest, and spatializing population based on the Random Forest model. After accuracy assessments by comparing with WorldPop, the proposed method was validated as a qualified method to generate fine-resolution population spatial maps. In the discussion, this paper suggested that without help of auxiliary data, NTL cannot be directly employed as a population indicator at small scale. The Variable Importance Measure of the RF model confirmed the correlation between features and population and further demonstrated that urban functions performed better than LULC (Land Use and Land Cover) in small-scale population mapping. Urban height was also shown to improve the performance of population disaggregation due to its compensation of building volume. To sum up, this proposed method showed great potential to disaggregate fine-resolution population and other urban socio-economic attributes.

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Population Dynamics of Drosophila suzukii in Coastal and Mainland Sweet Cherry Orchards of Greece

Insects ◽

10.3390/insects11090621 ◽

2020 ◽

Vol 11 (9) ◽

pp. 621

Author(s):

Stella A. Papanastasiou ◽

Vasilis G. Rodovitis ◽

Evmorfia P. Bataka ◽

Eleni Verykouki ◽

Nikos T. Papadopoulos

Keyword(s):

Population Dynamics ◽

Coastal Area ◽

Sweet Cherry ◽

Coastal Areas ◽

Drosophila Suzukii ◽

Apple Cider ◽

Mediterranean Countries ◽

Southern Mediterranean ◽

Wild Hosts ◽

Of Greece

Despite the recent invasion and wide spread of Drosophila suzukii Matsumura (Diptera: Drosophilidae) in Europe, little is known regarding its population trends in coastal areas of the southern Mediterranean countries. Using adult trapping and fruit sampling, we studied the population dynamics of D. suzukii in coastal and mainland (semi-highland) cherry orchards of Greece, from 2018 to 2020. Adults were captured in traps baited with apple cider vinegar, placed in conventional and unmanaged sweet-cherry orchards, and in neighbouring wild growing hosts. Sampling of sweet-cherry fruit to assess infestation levels was conducted from early and late-ripening cherry cultivars in both areas. Adults were captured throughout the year in the coastal area with two peaks registered in spring and late-autumn. Captures were nearly zero during the hot summer months. Flight activity exhibited only one peak in autumn at the mainland area, and ceased during winter and spring. Captures in wild hosts were lower during the sweet-cherry ripening period than later in the season. Higher sweet-cherry infestation levels were recorded in the coastal than in the mainland area and in unmanaged than in commercial orchards. Both early and late-ripening cultivars were highly susceptible to D. suzukii infestation in the coastal area. Infestation rates were higher in late-ripening cultivars than in early-ripening ones in the mainland area. We conclude that D. suzukii has well adapted to the Mediterranean climate of Greece, and is able to progressively exploit several crops and wild hosts of mainland and coastal areas.

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