Experimental studies on acarine predator–prey interactions: effects of predator age and feeding history on prey consumption and the functional response (Acarina: Phytoseiidae)

1981 ◽  
Vol 59 (7) ◽  
pp. 1387-1406 ◽  
Author(s):  
Eldon S. Eveleigh ◽  
D. A. Chant
Keyword(s):  
Functional Response ◽  
Prey Density ◽  
Laboratory Experiments ◽  
Prolonged Exposure ◽  
Experimental Studies ◽  
Phytoseiulus Persimilis ◽  
Functional Responses ◽  
Phytoseiid Mites ◽  
Predatory Behaviour ◽  
Predator Prey

Laboratory experiments were performed to determine the functional response to prey density of various instars of two species of predacious phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, and to examine the effects of predator age and nutritional history on their responses. The experiments showed that the nutritional requirements of the predators, the time that they are exposed to prey in relation to their life-span, increasing age, and differences in nutritional history, can have important effects on predatory behaviour and the functional response. Prolonged exposure to one density of prey can cause lags in predation rates when the prey density is changed. The results indicated that functional responses are probably multiform in certain predators and the above factors may provide an explanation of the variety of responses previously reported for species of phytoseiid mites. Phytoseiulus persimilis appeared to be more sensitive to some of these factors than A. degenerans and was shown to be different in many aspects of its predatory behaviour.

Experimental studies on acarine predator–prey interactions: the response of predators to prey distribution in an homogeneous area (Acarina: Phytoseiidae)

1982 ◽  
Vol 60 (4) ◽  
pp. 639-647 ◽  
Author(s):  
Eldon S. Eveleigh ◽  
D. A. Chant
Keyword(s):  
Functional Response ◽  
Prey Density ◽  
Experimental Studies ◽  
Phytoseiulus Persimilis ◽  
Phytoseiid Mites ◽  
Predator Prey ◽  
Prey Distribution ◽  
Uniform Distributions ◽  
Homogeneous Area ◽  
Prey Depletion

A laboratory study was conducted to determine the effects of prey distribution in an homogeneous area on the searching success and functional response of two species of phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans. The results indicated that the spatial distribution of the prey affected the searching success and functional response of P. persimilis but not of A. degenerans. More prey were killed by the former predator when prey were clustered, followed by random and uniform distributions. In contrast to A. degenerans, the degree of prey aggregation at a given prey density also affected the number of prey killed by P. persimilis. With both predators, prey depletion affected the comparative success of the predators at certain prey distributions. It is concluded that P. persimilis is adapted to search for prey which aggregate, whereas A. degenerans is not. The results are discussed in terms of their potential importance in predation and biological control studies.

Experimental studies on acarine predator–prey interactions: the effects of predator density on immature survival, adult fecundity and emigration rates, and the numerical response to prey density (Acarina: Phytoseiidae)

1982 ◽  
Vol 60 (4) ◽  
pp. 630-638 ◽  
Author(s):  
Eldon S. Eveleigh ◽  
D. A. Chant
Keyword(s):  
Prey Density ◽  
Laboratory Experiments ◽  
Survival Rates ◽  
Experimental Studies ◽  
Phytoseiulus Persimilis ◽  
Numerical Response ◽  
Predator Density ◽  
Predator Prey ◽  
Immature Survival

Laboratory experiments revealed that increasing the density of the immature instars of Phytoseiulus persimilis had little effect on their survival rates. However, due to the high prey requirements of the immature instars of Amblyseius degenerans and the tendency for underfed individuals of this species to become cannibalistic, their survival rates decreased with increasing predator density. Increasing predator density reduced the fecundity of P. persimilis and caused its numerical response to prey density to reach plateaux at increasingly lower levels of fecundity as the predator density increased. In contrast, increasing predator density did not affect the fecundity of A. degenerans to such an extent and its numerical response appeared eventually to reach maximum levels when sufficient prey were available. The emigration rates of P. persimilis tended to increase with increasing predator density whereas those of A. degenerans increased or decreased depending on the density of the predators and the prey.

Experimental studies on acarine predator–prey interactions: the numerical response of immature and adult predators (Acarina: Phytoseiidae)

1981 ◽  
Vol 59 (7) ◽  
pp. 1407-1418 ◽  
Author(s):  
Eldon S. Eveleigh ◽  
D. A. Chant
Keyword(s):  
Prey Density ◽  
Survival Rates ◽  
Experimental Studies ◽  
Phytoseiulus Persimilis ◽  
Phytoseiid Mites ◽  
Searching Behaviour ◽  
Predator Prey ◽  
Adult Females ◽  
History Of ◽  
Adult Lives

The numerical responses of two species of phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, were studied in the laboratory. Developmental times and survival rates were examined in the immature instars and oviposition rates in adult females. Prey requirements for development, survival, and oviposition were lower with P. persimilis than A. degenerans due to the nature of their respective feeding and searching behaviour. The fecundity of P. persimilis increased linearly with increasing numbers of prey killed, whereas that of A. degenerans increased curvilinearly. Experiments on the effects of the feeding history of adult females on their fecundity showed that their response depended not only on their most recent nutritional history but also on prey conditions experienced early in their adult lives. The ability of the females to respond to an increase in prey density may be enhanced or reduced depending on the prey conditions experienced. The manner in which the requirements for prey, and the feeding and searching behaviour of the predators, influenced their responses is discussed.

Experimental studies on acarine predator–prey interactions: the effects of predator density on prey consumption, predator searching efficiency, and the functional response to prey density (Acarina: Phytoseiidae)

1982 ◽  
Vol 60 (4) ◽  
pp. 611-629 ◽  
Author(s):  
Eldon S. Eveleigh ◽  
D. A. Chant
Keyword(s):  
Functional Response ◽  
Adult Female ◽  
Experimental Studies ◽  
Phytoseiulus Persimilis ◽  
Predator Density ◽  
Response Curves ◽  
Phytoseiid Mites ◽  
Predator Prey ◽  
The Individual ◽  
Predation Rates

Experiments on the responses of two species of predacious phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, to their own density revealed that, with the exception of adult female P. persimilis, the individual predation rates of all instars of both species increased as predator and prey densities were increased within certain fixed predator to prey ratios. "Interference" between adult female P. persimilis was suggested as a possible reason for this result, and this was confirmed by the application of Hassell and Varley's model to data from an experiment where predator density was increased within various prey densities. Interference did not influence the predation rates for other instars of either species and other factors are considered to account for the results obtained.Increasing predator density caused the functional response of all instars of both species to increase over an increasingly wider range of prey densities. However, due to interference between adult female P. persimilis the functional response curves increased curvilinearly and reached plateaux at progressively lower levels of prey killed per predator as predator density increased. With the other instars of both species the responses became less curvilinear with increasing predator density, and trends in the data suggested that plateaux would be reached at similar levels of prey killed for different predator densities provided sufficient prey are present.

Experimental studies on acarine predator–prey interactions: the distribution of search effort and the functional and numerical responses of predators in a patchy environment (Acarina: Phytoseiidae)

1982 ◽  
Vol 60 (12) ◽  
pp. 2979-2991 ◽  
Author(s):  
Eldon S. Eveleigh ◽  
D. A. Chant
Keyword(s):  
Reproductive Output ◽  
Experimental Studies ◽  
Phytoseiulus Persimilis ◽  
Patchy Environment ◽  
Functional Responses ◽  
Predator Prey ◽  
Search Effort ◽  
Aggregative Response ◽  
Predation Rates ◽  
Main Factor

Laboratory experiments revealed that Phytoseiulus persimilis distributed its search effort in relation to prey density in a patchy environment, whereas Amblyseius degenerans distributed its search effort randomly among patches of prey. The main factor responsible for the aggregative response of P. persimilis was the length of its first visit to the patches. Although the functional responses of both predators changed with time, only those of P. persimilis closely reflected changes occurring in its distribution of search effort. The spatial complexity of the environment did not affect the overall predation rates of P. persimilis but it reduced its reproductive output. However, the predation rates of A. degenerans were adversely affected, suggesting that its fecundity would also be reduced in a spatially complex environment. Phytoseiulus persimilis distributed its progeny among patches containing relatively high prey densities and avoided ovipositing in the patch containing fewest prey. Neither species foraged optimally and possible reasons for this are discussed.

The feeding and searching behaviour of two species of phytoseiid mites, Phytoseiulus persimilis Athias-Henriot and Amblyseius degenerans (Berlese), at different prey densities (Acarina: Phytoseiidae)

1981 ◽  
Vol 59 (7) ◽  
pp. 1419-1430 ◽  
Author(s):  
Eldon S. Eveleigh ◽  
D. A. Chant
Keyword(s):  
Prey Density ◽  
Phytoseiulus Persimilis ◽  
Phytoseiid Mites ◽  
Predatory Behaviour ◽  
Searching Behaviour ◽  
Lower Capacity

Detailed observations were made on various components of the predatory behaviour of each instar of two species of predacious phytoseiid mites, Phytoseiulus persimilis and Amblyseius degenerans, in the laboratory. These observations revealed that many aspects of the feeding and searching behaviour of these predators are dependent on the prey density to which they are exposed. Differences between the two species are described and it is concluded that P. persimilis has a greater ability to modify its behaviour in relation to prey conditions than A. degenerans. The results explain why P. persimilis has a lower capacity for prey and lower prey requirements for survival, development, and reproduction than A. degenerans, and also the nature of the functional and numerical responses to prey density of the two species.

scholarly journals Applying predator-prey theory to modelling immune-mediated, within-host interspecific parasite interactions

Parasitology ◽  
2010 ◽  
Vol 137 (6) ◽  
pp. 1027-1038 ◽  
Author(s):  
ANDY FENTON ◽  
SARAH E. PERKINS
Keyword(s):  
Functional Response ◽  
Interspecific Interactions ◽  
Parasite Load ◽  
Multiple Infections ◽  
Functional Responses ◽  
Predator Prey ◽  
Immune Activity ◽  
Parasite Communities ◽  
Immune Mediated ◽  
Predator Prey Models

SUMMARYPredator-prey models are often applied to the interactions between host immunity and parasite growth. A key component of these models is the immune system's functional response, the relationship between immune activity and parasite load. Typically, models assume a simple, linear functional response. However, based on the mechanistic interactions between parasites and immunity we argue that alternative forms are more likely, resulting in very different predictions, ranging from parasite exclusion to chronic infection. By extending this framework to consider multiple infections we show that combinations of parasites eliciting different functional responses greatly affect community stability. Indeed, some parasites may stabilize other species that would be unstable if infecting alone. Therefore hosts' immune systems may have adapted to tolerate certain parasites, rather than clear them and risk erratic parasite dynamics. We urge for more detailed empirical information relating immune activity to parasite load to enable better predictions of the dynamic consequences of immune-mediated interspecific interactions within parasite communities.

scholarly journals Permanence of Periodic Predator-Prey System with Functional Responses and Stage Structure for Prey

2008 ◽  
Vol 2008 ◽  
pp. 1-15 ◽  
Author(s):  
Can-Yun Huang ◽  
Min Zhao ◽  
Hai-Feng Huo
Keyword(s):  
Functional Response ◽  
Prey Species ◽  
Necessary Conditions ◽  
Stage Structure ◽  
Functional Responses ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Prey System ◽  
Sufficient And Necessary Conditions ◽  
Holling Ii Functional Response

A stage-structured three-species predator-prey model with Beddington-DeAngelis and Holling II functional response is introduced. Based on the comparison theorem, sufficient and necessary conditions which guarantee the predator and the prey species to be permanent are obtained. An example is also presented to illustrate our main results.

Predator Ecology

2021 ◽  
Author(s):  
John P. DeLong
Keyword(s):  
Food Webs ◽  
Functional Response ◽  
Behavioral Ecology ◽  
Evolutionary Dynamics ◽  
Ecological Systems ◽  
Ecological Communities ◽  
Functional Responses ◽  
Predator Prey ◽  
Top Predators ◽  
Integrative Science

Predator-prey interactions form an essential part of ecological communities, determining the flow of energy from autotrophs to top predators. The rate of predation is a key regulator of that energy flow, and that rate is determined by the functional response. Functional responses themselves are emergent ecological phenomena – they reflect morphology, behavior, and physiology of both predator and prey and are both outcomes of evolution and the source of additional evolution. The functional response is thus a concept that connects many aspects of biology from behavioral ecology to eco-evolutionary dynamics to food webs, and as a result, the functional response is the key to an integrative science of predatory ecology. In this book, I provide a synthesis of research on functional responses, starting with the basics. I then break the functional response down into foraging components and connect these to the traits and behaviors that connect species in food webs. I conclude that contrary to appearances, we know very little about functional responses, and additional work is necessary for us to understand how environmental change and management will impact ecological systems

Some Characteristics of Simple Types of Predation and Parasitism

1959 ◽  
Vol 91 (7) ◽  
pp. 385-398 ◽  
Author(s):  
C. S. Holling
Keyword(s):  
Functional Response ◽  
Small Mammals ◽  
Prey Density ◽  
Population Regulation ◽  
Predator Prey

In an earlier study (Holling, 1959) the basic and subsidiary components of predation were demonstrated in a predator-prey situation involving the predation of sawfly cocoons by small mammals. One of the basic components, termed the functional response, was a response of the consumption of prey by individual predators to changes of prey density, and it appeared to be at least theoretically important in population regulation: Because of this importance the functional response has been further examined in an attempt to explain its characteristics.

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