scholarly journals Seasonal fluctuations of population density of the cabbage aphid,Brevicoryne brassicae (L.), in the Netherlands, and the role of its parasite,Aphidius (Diaeretiella) rapae (Curtis)

1961 ◽  
Vol 67 (5) ◽  
pp. 345-548 ◽  
Author(s):  
M. Hafez
Keyword(s):  
Population Density ◽  
The Netherlands ◽  
Brevicoryne Brassicae ◽  
Diaeretiella Rapae ◽  
Seasonal Fluctuations ◽  
Cabbage Aphid

scholarly journals Influence of the Surrounding Plants by Rapeseed Field on Population Density of Cabbage Aphid (Brevicoryne brassicae L.) and its Biological Enemies

2010 ◽  
Vol 7 (1) ◽  
pp. 246-253
Author(s):  
Baghdad Science Journal
Keyword(s):  
Population Density ◽  
Cover Crops ◽  
Brevicoryne Brassicae ◽  
Cabbage Aphid

The result revealed that the peak of population density of cabbage aphid Brevicoryne brassicae was 523.20 individuals/plant on 21 March in edges of rapeseed field and was 1141.67 individuals/plant in center of the field. Results revealed that population density of cabbage aphid in rapeseed fields surrounded by cover crops significantly were low compared with that of monoculture rapeseed. The location of rapeseed plants (in edges or in center) significantly affected (p

POPULATION DYNAMICS OF THE CABBAGE APHID, BREVICORYNE BRASSICAE (HOMOPTERA: APHIDIDAE) AT VANCOUVER, BRITISH COLUMBIA: V. A SIMULATION MODEL

1984 ◽  
Vol 116 (6) ◽  
pp. 895-911 ◽  
Author(s):  
D. A. Raworth
Keyword(s):  
British Columbia ◽  
Population Dynamics ◽  
Major Change ◽  
Brevicoryne Brassicae ◽  
Diaeretiella Rapae ◽  
Simulated Population ◽  
Aphidoletes Aphidimyza ◽  
Functional Responses ◽  
Cabbage Aphid ◽  
Effects Of Temperature

AbstractA computer model was written to simulate the population dynamics of the cabbage aphid, Brevicoryne brassicae (L.), on the host Maris Kestrel kale, Brassica oleracea L., at Vancouver, British Columbia. The model incorporated the effects of temperature, morph determination, plant quality, predators, parasites, and leaf fall. Comparisons of simulated results with field observations indicated that although B. brassicae, Aphidoletes aphidimyza (Rond.), and Diaeretiella rapae (M'Intosh) were reasonably well understood, syrphid predation was not, and appropriate feed-back mechanisms which could prevent monotonic increase or decrease in the simulated population were lacking. A detailed study in which the population dynamics of the prey is accounted for in terms of the numerical and functional responses of syrphid predators is necessary to understand the population dynamics of B. brassicae on Maris Kestrel kale at Vancouver. Comparisons with other aphid systems suggest that a major change in one component of the system can be compensated for by changes in other components. An overview of the cabbage aphid system at Vancouver is given.

scholarly journals Field Screening of Seven Cultivars of Cabbage Against Cabbage Butterfly (Pieris brassicae) and Cabbage Aphids (Brevicoryne brassicae) at Gkuleshor, Baitadi, Nepal

2020 ◽  
Vol 14 (1) ◽  
pp. 63-67
Author(s):  
Narendra Bahadur Singh ◽  
Santosh Dhungana ◽  
Srijana Adhikari ◽  
Dipesh Chapagain ◽  
Nawaraj Ghimire ◽  
...  
Keyword(s):  
Population Density ◽  
Pieris Brassicae ◽  
Brevicoryne Brassicae ◽  
Animal Science ◽  
Field Screening ◽  
Cabbage Aphid ◽  
Cabbage Butterfly ◽  
Science College ◽  
Butterfly Population ◽  
Cabbage Aphids

Field screening of seven cultivars of cabbage namely: Green Crown, Green Top, Green Coronet, Pioneer, Nepa Round, Copenhagen Market and Golden Acre were carried out against cabbage butterfly (Pieris brassicae) and cabbage aphid (Brevicoryne brassicae) at the research farm of entomology section, Gokuleshwor Agriculture and Animal Science College, Baitadi in RCBD design from October 2017 to February 2018. Five plants were tagged randomly after transplanting in field excluding border plants in each plot. Data were collected for the population dynamics of cabbage butterfly larvae and cabbage aphid on weekly basis. None of the seven cultivars were found resistant to cabbage butterfly and cabbage aphid, however their population density varied on tested cultivars. Cabbage butterfly population was recorded the highest on the cultivar Pioneer (22.88 larvae/plant) and the lowest on the cultivar Copenhagen Market (10.06 larvae/plant), and other cultivars were of intermediate types. Similarly, the population density of aphid ranged from 36.70 to 105.58 aphids/leaf. The highest population density of aphid was recorded on cultivar Green Crown (105.58 aphids/leaf) and the lowest on cultivar Copenhagen Market (39.82 aphids/leaf. From the results, Copenhagen Market proved to be the best against both cabbage butterfly and cabbage aphids.

The role of seasonality in vole cycles

1986 ◽  
Vol 64 (12) ◽  
pp. 2871-2872 ◽  
Author(s):  
Richard S. Ostfeld ◽  
Robert H. Tamarin
Keyword(s):  
Population Density ◽  
Food Availability ◽  
Population Fluctuations ◽  
High Population Density ◽  
Vole Population ◽  
Seasonal Fluctuations ◽  
Microtus Californicus ◽  
Vole Cycles ◽  
California Vole

We examined the assertion that seasonal fluctuations in food availability are necessary for vole cycles to take place by studying the dynamics of a California vole (Microtus californicus) population inhabiting a relatively aseasonal environment. That population was one of the most stable (noncyclic) microtine populations yet described. Reproduction was comparatively aseasonal but appeared to be suppressed at high population density. We suggest that the role of seasonality in vole population fluctuations deserves further study.

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