THE DYNAMICS OF APHIS POMI DE GEER (HOMOPTERA: APHIDIDAE) AND ITS PREDATOR, APHIDOLETES APHIDIMYZA (RONDANI) (DIPTERA: CECIDOMYIIDAE), ON APPLE IN NOVA SCOTIA

1997 ◽  
Vol 129 (4) ◽  
pp. 627-636 ◽  
Author(s):  
Heather C. Stewart ◽  
Sandra J. Walde
Keyword(s):  
Population Dynamics ◽  
Nova Scotia ◽  
Density Dependence ◽  
Growing Season ◽  
Predation Rate ◽  
Apple Orchard ◽  
Predator Population ◽  
Aphidoletes Aphidimyza ◽  
Predator Density ◽  
Aphis Pomi

AbstractThe dynamics of Aphis pomi De Geer (Homoptera: Aphididae) and its predator, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae), were studied over two seasons in a commercial apple orchard in Nova Scotia. Aphid and predator population dynamics were very different in the two seasons. The most numerous predator in both years was A. aphidimyza. This predator was found in the earliest colonies sampled each season and was present throughout the growing season. In the year with relatively high aphid densities a single peak in aphid and predator density was seen in mid-July, just prior to maximum predation rate. The predator’s numerical response resulted in delayed density dependence in predation rate. In the year of low aphid densities, predator and prey dynamics appeared uncoupled, and a higher rate of colony turnover may have been caused by other predators such as mirids. Aphidoletes aphidimyza tended to aggregate oviposition in high-density aphid colonies, but this aggregation resulted in predation that was only very weakly spatially density dependent.

PREDATION BY INSECTS AND SPIDERS INHABITING COLONIAL WEBS OF HYPHANTRIA CUNEA

1972 ◽  
Vol 104 (8) ◽  
pp. 1197-1207 ◽  
Author(s):  
R. F. Morris
Keyword(s):  
Population Dynamics ◽  
Nova Scotia ◽  
North America ◽  
Population Density ◽  
New Brunswick ◽  
Numerical Response ◽  
Initial Number ◽  
Hyphantria Cunea ◽  
The North ◽  
The Mean

AbstractThe number of predators inhabiting nests of Hyphantria cunea Drury was recorded annually for 13 years in four areas in New Brunswick and two areas on the coast of Nova Scotia. The most common groups were the pentatomids and spiders, which sometimes reproduced within the nests, but the mean number per nest was low in relation to the number of H. cunea larvae in the colonies. The rate of predation on fifth-instar larvae was low. Small or timid predators appeared to prey largely on moribund larvae or small saprophagans during the principal defoliating instars of H. cunea.No relationship could be detected between the number of larvae reaching the fifth instar and the number of predators in the colony; nor could any functional or numerical response of the predators to either the initial number of larvae per colony or the population density of colonies be found. It is concluded that the influence of the nest-inhabiting predators is small and relatively stable, and may be treated as a constant in the development of models to explain the population dynamics of H. cunea.H. cunea is a pest in parts of Europe and Asia, where it has been accidentally introduced from North America. The introduction to other continents of the North American predator, Podisus maculiventiis (Say), is discussed briefly.

The effect of predator population dynamics on Batesian mimicry complexes

2021 ◽  
Author(s):  
David Kikuchi ◽  
Michael Barfield ◽  
Marie E Herberstein ◽  
Johanna Mappes ◽  
Robert D. Holt
Keyword(s):  
Population Dynamics ◽  
Batesian Mimicry ◽  
Predator Population

scholarly journals LATE BLOOMING OF PLANTS FROM NORTHERN NOVA SCOTIA: RESPONSES TO A MILD FALL AND WINTER

2011 ◽  
Vol 46 (2) ◽  
Author(s):  
David J. Garbary ◽  
Jonathan Ferrier ◽  
Barry R. Taylor
Keyword(s):  
Climate Change ◽  
Nova Scotia ◽  
Woody Plants ◽  
Regional Climate ◽  
Growing Season ◽  
Flowering Phenology ◽  
Flowering Date ◽  
Cornus Sericea ◽  
Allium Schoenoprasum ◽  
Herbaceous Dicots

Over 1400 flowering records of 135 species were recorded from over 125visits to more than 20 sites in Antigonish County, Nova Scotia from November2005 to January 2006, when the growing season is normally over. The speciesidentified were primarily herbaceous dicots; however, there were four speciesof woody plants (Cornus sericea, Spiraea latifolia, Symphoricarpos albusand Salix sp.) and one monocot (Allium schoenoprasum). The number ofspecies flowering declined linearly as fall progressed, as did the amountof flowering for each species. Nevertheless, over 40 species were still inflower in early December, and over 20 species flowered in January. Thefinal flowering date was 21 January, when ten species were found. Thiswork builds on a previous study in 2001, when 93 species were recordedin flower during November-December. In addition to the 30% increase inrecorded species in 2005, almost 50% of the species found in 2005 werenot recorded in 2001. This study provides an expanded baseline againstwhich changes in flowering phenology can be evaluated with respect tosubsequent regional climate change.Key Words: Antigonish, flowering, Nova Scotia, phenology, climate change

scholarly journals Effects of temporal variation in temperature and density dependence on insect population dynamics

Ecosphere ◽  
2016 ◽  
Vol 7 (5) ◽  
Author(s):  
C. V. Haridas ◽  
Lance J. Meinke ◽  
Bruce E. Hibbard ◽  
Blair D. Siegfried ◽  
Brigitte Tenhumberg
Keyword(s):  
Population Dynamics ◽  
Temporal Variation ◽  
Density Dependence ◽  
Insect Population ◽  
Insect Population Dynamics

scholarly journals The Effect of Conspecific Density on Emergence ofLestes bipupillatusCalvert, 1909 (Odonata: Lestidae)

2014 ◽  
Vol 2014 ◽  
pp. 1-3 ◽  
Author(s):  
Ricardo Cardoso-Leite ◽  
Gabriel C. Vilardi ◽  
Rhainer Guillermo-Ferreira ◽  
Pitágoras C. Bispo
Keyword(s):  
Population Dynamics ◽  
Density Dependence ◽  
Social Environment ◽  
Growth Rates ◽  
High Density ◽  
Conspecific Density ◽  
Simulated Environments ◽  
The Social ◽  
Emergence Date

Conspecific density may influence adult recruitment and consequently population dynamics. Several studies have shown the density dependence of larvae growth rates in Odonata. However, few studies studied how conspecific density influence final instar larvae emergence date decisions. Considering that larvae may choose the date of emergence, the present study investigated if density affects larvae choice. For this, we reared eight final instar larvae in individual aquaria and other 24 larvae in aquaria with three larvae each. This way, we simulated environments with low and high larval densities. We then noted the days that larvae took to emerge and compared it between low and high density groups. The results showed that larvae seem to emerge earlier when in high densities (Mann-Whitney,U=10.000,P=0.03). These results support the hypothesis that damselfly last instar larvae may postpone or hasten emergence in response to the social environment and related constraints.

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