scholarly journals Monitoring population density and fluctuations of Xyleborus dispar and Xyleborinus saxesenii (Coleoptera: Scolytıdae) with red winged sticky traps in hazelnut orchards

2013 ◽  
Vol 8 (19) ◽  
pp. 2189-2194 ◽  
Author(s):  
Saruhan Islam ◽  
Akyol Huuml seyin
Keyword(s):  
Population Density ◽  
Sticky Traps ◽  
Xyleborus Dispar

scholarly journals Seasonal Phenology, Management, and Host Preferences of Potato Leafhopper on Nursery-Grown Maples

1993 ◽  
Vol 11 (3) ◽  
pp. 101-106
Author(s):  
Daniel A. Potter ◽  
Patricia G. Spicer
Keyword(s):  
Population Density ◽  
Acer Rubrum ◽  
Synthetic Pyrethroid ◽  
Potato Leafhopper ◽  
Empoasca Fabae ◽  
Red Maple ◽  
Sticky Traps ◽  
Host Preferences ◽  
Foliar Sprays ◽  
And Control

Abstract Seasonal phenology and control of the potato leafhopper (Empoasca fabae (Harris)) on red maples (Acer rubrum L.) were studied for three years in nurseries in central Kentucky. Migratory adult leafhoppers were first captured on yellow sticky traps in early May. Peak population density ranged from late May to late June. The second flush of leaves was most heavily damaged in each year. Foliar sprays of cyfluthrin (Tempo 2), a synthetic pyrethroid, beginning 1 to 2 weeks after first capture of leathoppers and repeated at biweekly intervals during May and June, greatly reduced symptoms of injury. Acephate (Orthene) was less effective than cyfluthrin, whereas treatment of the soil with disulfoton (Di-syston) was ineffective. Oviposition and development of the leafhopper on red maple were confirmed. Field evaluations of selected cultivars showed that red maples were more severely damaged than sugar (A. saccharum L.) or Norway (A. platanoides L.) maples. ‘Autumn Blaze’, an A. rubrum × saccharinum hybrid, was relatively resistant.

DENSIDAD POBLACIONAL DE MOSCABLANCA Bemisia spp. (HEMIPTERA: ALEYROIDIDAE) EN EL VALLE DE GUAYMAS-EMPALME, SONORA, MÉXICO/ POPULATION DENSITY OF WHITEFLY IN THE GUAYMAS-EMPALME VALLEY, SONORA, MEXICO

Biotecnia ◽  
2016 ◽  
Vol 18 (3) ◽  
pp. 9-13
Author(s):  
Juan José Pacheco-Covarrubias ◽  
Joel Soto Nolasco ◽  
Juan Manuel Valenzuela Valenzuela
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Bemisia Tabaci ◽  
The Other ◽  
Sticky Traps ◽  
Influence Of Temperature ◽  
Heat Units ◽  
Pest Infestation ◽  
Important Pest ◽  
Number Of Individuals

La mosca blanca (Bemisia tabaci) es la plaga más importante en el valle de Guaymas-Empalme, Sonora. Se determinó su densidad poblacional mediante la captura regional de adultos a través de trampas amarillas pegajosas. Los resultados indican valores de pendiente de 0.011, 0.014, 0.0045 y 0.0027 para los ciclos 2011-12, 2012-13, 2013-14 y 2014-15, respectivamente; dichos valores son diferentes estadísticamente entre sí (0.01) prueba de “t”. Por otra parte, el número promedio de individuos capturados por semana para los ciclos antes mencionados fue de 0.67, 0.80, 0.31 y 0.14, respectivamente. Finalmente, el cálculo del número de generaciones que en teoría se pueden acumular mediante Unidades Calor fue de 13.5, 9.36, 15.32, 11.96, para los ciclos antes mencionados. Los resultados no detectan evidencia determinante de la influencia de la temperatura ni del alimento sobre el crecimiento poblacional de la plaga, por lo que el manejo de focos de infestación de la plaga y el ordenamiento de fechas de cultivos son determinante para la definición del estatus fitosanitario de la plaga. ABSTRACT Whitefly is the most important pest in the Guaymas-Empalme valley, Sonora. México. The population density of whitefly was evaluated trough regional capture of whitefly adults through yellow sticky traps. The data indicate slope values of 0.011, 0.014, 0.0045 and 0.0027 for 2011-12 , 2012-13, 2013-14 and 2014-15 cycles, respectively; these values are statistically different from each other (0.01) test “t”. Moreover, the average number of individuals caught weekly was 0.67, 0.80, 0.31 and 0.14. Finally, the number of generations which in theory can be accumulated by heat units was 13.5, 9.36, 15.32, 11.96. The results did not detect evidence of the influence of temperature and crops on the population growth of the pest; on the other hand the management of outbreaks of pest infestation and crop dates control are crucial for defining the pest status.

A population study of the coconut pest Segestidea uniformis (Willemse) (Orthoptera: Tettigoniidae) on an equatorial island

1984 ◽  
Vol 74 (3) ◽  
pp. 439-451 ◽  
Author(s):  
P. M. Room ◽  
C. H. Perry ◽  
P. T. Bailey
Keyword(s):  
Biological Control ◽  
Population Density ◽  
Sex Ratio ◽  
Papua New Guinea ◽  
Population Study ◽  
Small Island ◽  
Population Fluctuations ◽  
Sticky Traps ◽  
First Instar ◽  
Nut Production

AbstractA population of the coconut pest Segestidea uniformis (Willemse) was monitored on a small island 2° from the equator in Papua New Guinea between 1973 and 1978. Totals of 54 000 first-instar nymphs were caught on sticky traps on palm trunks and 8750 other nymphs and adults were recovered from the crowns of palms. Generations were completely overlapping, and there was no evidence of seasonality in population fluctuations. The sex ratio was 50:50 in the first six instars, but 90% of seventh instars and 30% of adults were female. Explanations for these variations are given. The population declined from an annual mean of 24 individuals of all ages per palm crown in 1973 to 9 in 1976 and increased again to 29 in 1978. Most post-hatching mortality occurred as first instars climbed from the ground to the crown of palms, probably due to the lizard Gehyra oceanica and rainfall. The number of adults was more sensitive to mortality occurring after the first instars had arrived in the crowns. This mortality appeared to be related to the duration of periods without rainfall, supporting earlier observations that damaging outbreaks of S. uniformis populations do not occur in places which experience a regular dry season. Production of coconuts appeared to be inversely related to the population density of S. uniformis, which did not rise above a level estimated to cause 20% defoliation of the palms during the study. Nut production also seemed to be related to the number of hours of sunshine received in the preceding 12 months. Biological control aimed at nymphs and adults in palm crowns is suggested as an option for controlling S. uniformis which deserves investigation.

scholarly journals Evaluation of relative sampling methods for population estimation of the pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae)

1969 ◽  
Vol 72 (3) ◽  
pp. 387-393
Author(s):  
Alejandro E. Segarra-Carmona ◽  
Alberto Pantoja
Keyword(s):  
Population Density ◽  
Sampling Methods ◽  
Population Estimation ◽  
Sticky Traps ◽  
Factors Affecting ◽  
Anthonomus Eugenii ◽  
Pepper Weevil ◽  
Dark Green ◽  
Light Green ◽  
Yellow Sticky Traps

Five sampling methods were evaluated simultaneously for their efficiency in estimating pepper weevil (Anthonomus eugenii Cano) populations. The use of yellow sticky traps was assessed superior to other methods when correlated with direct weevil counts. Comparison between sticky traps of eight different colors indicated that yellow and white traps are significantly more attractive to pepper weevils than light green, red, dark green, gray, blue or black. Commercially available Pherocon AM traps were tested for efficiency. Weevil catch in these traps was positively correlated with population density, but relationship was weak and weekly catch erratic. Factors affecting trap efficiency are mentioned.

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.

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