scholarly journals Use of pheromones for monitoring of the Asiatic leafroller, Archippus breviplicanus (Lepidoptera: Tortricidae). I. Effect of trap height, flight activity and population density on male catches.

1987 ◽  
Vol 31 (2) ◽  
pp. 103-109 ◽  
Author(s):  
Rikio SATO ◽  
Kaoru YAGINUMA ◽  
Hajime SUGIE
Keyword(s):  
Population Density ◽  
Flight Activity ◽  
Trap Height

scholarly journals Monitoring Flight Activity of Ambrosia Beetles in Ornamental Nurseries with Ethanol-Baited Traps: Influence of Trap Height on Captures

2010 ◽  
Vol 28 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Michael Reding ◽  
Jason Oliver ◽  
Peter Schultz ◽  
Chris Ranger
Keyword(s):  
Flight Activity ◽  
Cornus Florida ◽  
Ambrosia Beetles ◽  
Main Trunk ◽  
Baited Traps ◽  
Trap Height ◽  
Ground Monitoring ◽  
Xylosandrus Germanus

Abstract Ethanol-baited bottle traps were used to monitor spring flight activity of the ambrosia beetles Xylosandrus crassiusculus and Xylosandrus germanus in Ohio, Tennessee, and Virginia. The traps were deployed at three different heights to determine if height influenced captures. X. germanus was captured in all three states, while X. crassiusculus was captured in TN and VA only. Traps 0.5 m above the ground captured more X. germanus than traps at 1.7 or 3.0 m. Traps 0.5 or 1.7 m above the ground captured more X. crassiusculus than traps at 3.0 m. In TN and VA, first activity of X. crassiusculus and X. germanus occurred from mid-March to early April. In OH, first activity of X. germanus occurred early to mid-April. Analysis of attacks by X. germanus on Cornus florida revealed that more than 90% of the attacks occurred on the main trunk within 1 m (3 ft) of the ground. Monitoring will be most effective when traps are suspended 0.5 or < 1.7 m above the ground for X. germanus or X. crassiusculus, respectively. To detect first flight of X. crassiusculus or X. germanus, traps should be deployed by early to mid-March in TN and VA and late March in OH.

Convergence of regional population density in Russia over 120 years

2020 ◽  
pp. 133-158
Author(s):  
K. A. Kholodilin ◽  
Y. I. Yanzhimaeva
Keyword(s):  
Population Density ◽  
Spatial Dependence ◽  
Population Distribution ◽  
Regional Level ◽  
Capital City ◽  
County Level ◽  
Spatial Effects ◽  
Russian Regions ◽  
Regional Population ◽  
Regional Population Density

A relative uniformity of population distribution on the territory of the country is of importance from socio-economic and strategic perspectives. It is especially important in the case of Russia with its densely populated West and underpopulated East. This paper considers changes in population density in Russian regions, which occurred between 1897 and 2017. It explores whether there was convergence in population density and what factors influenced it. For this purpose, it uses the data both at county and regional levels, which are brought to common borders for comparability purposes. Further, the models of unconditional and conditional β-convergence are estimated, taking into account the spatial dependence. The paper concludes that the population density equalization took place in 1897-2017 at the county level and in 1926—1970 at the regional level. In addition, the population density increase is shown to be influenced not only by spatial effects, but also by political and geographical factors such as climate, number of GULAG camps, and the distance from the capital city.

Extension of the Spatial PDI Model to Three Dimensions

1997 ◽  
Vol 84 (1) ◽  
pp. 176-178
Author(s):  
Frank O'Brien
Keyword(s):  
Population Density ◽  
Dimensional Space ◽  
Finite Lattice ◽  
Three Dimensional ◽  
Upper Bounds ◽  
Three Dimensions ◽  
Lower And Upper Bounds ◽  
Density Index ◽  
Three Dimensional Space

The author's population density index ( PDI) model is extended to three-dimensional distributions. A derived formula is presented that allows for the calculation of the lower and upper bounds of density in three-dimensional space for any finite lattice.

Crop infestation by aphids is related to flight activity detected with 75 metre high suction traps

2004 ◽  
Vol 57 ◽  
pp. 227-232 ◽  
Author(s):  
D.A.J. Teulon ◽  
M.A.W. Stufkens ◽  
J.D. Fletcher
Keyword(s):  
Positive Relationship ◽  
Rhopalosiphum Padi ◽  
Flight Activity ◽  
Aphid Infestation ◽  
Potato Aphid ◽  
Suction Traps ◽  
Suction Trap ◽  
Trap Catches ◽  
The Relationship ◽  
High Suction

The flight activity of aphid pests of wheat potato lettuce and squash is currently monitored in New Zealand using 75 m suction traps However there has been little research comparing aphid suction trap catches with crop infestation levels The relationship between the average number of aphids (Rhopalosiphum padi) sampled from wheat plants and the average number of aphids caught in weekly 75 m suction trap samples was examined A significant positive relationship indicated that numbers of aphids caught in suction traps reflected the numbers of aphids infesting wheat fields In another experiment potato aphid flights (mostly Myzus persicae) caught in a 75 m suction trap were compared with a nearby windvane trap Aphid numbers in both traps reflected similar trends However the suction trap caught approximately 10 times more aphids than the windvane trap Thus 75 m suction traps provide a useful tool for assessing aphid infestation levels in crops

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