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: 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 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 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: effects of temporal changes in the environment on searching behaviour, predation rates, and fecundity (Acarina: Phytoseiidae)

1982 ◽  
Vol 60 (12) ◽  
pp. 2992-3000 ◽  
Author(s):  
Eldon S. Eveleigh ◽  
D. A. Chant
Keyword(s):  
Experimental Studies ◽  
Phytoseiulus Persimilis ◽  
Temporal Changes ◽  
Patchy Environment ◽  
Changing Environment ◽  
Searching Behaviour ◽  
Predator Prey ◽  
Prey Distribution ◽  
Predation Rates

We examined the effects of temporal changes in the environment on the searching behaviour, predation rates, and fecundity of Phytoseiulus persimilis and Amblyseius degenerans in the laboratory. Phytoseiulus persimilis demonstrated an ability to respond quickly to changes in prey distribution in a patchy environment and maintained its searching efficiency despite these changes. In contrast, A. degenerans was rather insensitive to temporal changes in prey distribution and when it found a profitable patch its visits to other patches were restricted. Thus, this species was unable to maintain its searching efficiency in the changing environment. Phytoseiulus persimilis distributed its progeny in relation to the distribution of prey in the changing environment and avoided oviposition in patches without prey, whereas A. degenerans showed no such discrimination. The fecundity of both species was not adversely affected by changes in prey distribution although their fecundity was lower than when all of the prey were in a single patch and their dispersal was restricted.

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.

The searching behaviour of two species of phytoseiid mites, Phytoseiulus persimilis Athias-Henriot and Amblyseius degenerans (Berlese), in relation to the density and distribution of prey in an homogeneous area (Acarina: Phytoseiidae)

1982 ◽  
Vol 60 (4) ◽  
pp. 648-658 ◽  
Author(s):  
Eldon S. Eveleigh ◽  
D. A. Chant
Keyword(s):  
Prey Capture ◽  
Phytoseiulus Persimilis ◽  
Absolute Magnitude ◽  
Phytoseiid Mites ◽  
Searching Behaviour ◽  
Different Types ◽  
Consistent Change ◽  
Homogeneous Area ◽  
The Absolute

Both Phytoseiulus persimilis and Amblyseius degenerans exhibited area-restricted searching after prey capture(s) regardless of the density and distribution of prey experienced. A reduction in searching speed and an increase in the absolute magnitude of turns following prey capture(s) contributed to area-restricted searching under all prey conditions with P. persimilis, whereas with A. degenerans, area-restricted searching was due to factors other than a consistent change in these searching parameters under all prey conditions. Phytoseiulus persimilis modified its overall searching behaviour to a greater extent at low than high prey densities and under clumped than uniform prey distributions, whereas A. degenerans showed similar postcapture behaviour under all prey conditions tested. The possible consequences of the behaviour of both predators on their searching success under different types of prey conditions are discussed.

THE FUNCTIONAL RESPONSE OF PHYTOSEIULUS PERSIMILIS (ACARINA: PHYTOSEIIDAE) TO VARIOUS DENSITIES OF TETRANYCHUS URTICAE (ACARINA: TETRANYCHIDAE)

1979 ◽  
Vol 111 (1) ◽  
pp. 7-10 ◽  
Author(s):  
P. Everson
Keyword(s):  
Functional Response ◽  
Tetranychus Urticae ◽  
Adult Female ◽  
Response Curve ◽  
Prey Density ◽  
Handling Time ◽  
Phytoseiulus Persimilis ◽  
Activity Level ◽  
Artificial Substrates ◽  
Successful Search

AbstractThe functional response of the predacious mite Phytoseiulus persimilis Athias-Henriot to increases in the prey density of adult female Tetranychus urticae Koch was examined. Previous studies on artificial substrates have described the functional response curve of P. persimilis to adult female prey as dome-shaped, because as prey density increased the predator was disturbed by prey activity.An experiment to determine the effect of artificial and natural substrates on the activity level of T. urticae was conducted. T. urticae showed a significant increase in activity on artificial substrates of plastic and waterproof paper compared with a substrate of excised bean leaf (Phaseolus vulgaris L.). Since prey activity was significantly influenced by substrate, the functional response of P. persimilis to adult female T. urticae was re-examined. P. persimilis exposed to various densities of T. urticae on excised bean leaf disks (5 cm2) showed a functional response curve having a curvilinear rise to a plateau as prey densities increased from 0.2 to 10.0 prey/cm2.The functional response curve predicted by Holling’s disk equation did not differ significantly from the observed functional response curve.The rate of successful search and the handling time predicted by the disk equation were 0.194 and 10.34 h respectively.

THE INFLUENCE OF PREY DENSITY, RELATIVE HUMIDITY, AND STARVATION ON THE PREDACIOUS BEHAVIOR OF PHYTOSEIULUS PERSIMILIS ATHIAS-HENRIOT (ACARINA: PHYTOSEIIDAE)

1966 ◽  
Vol 44 (3) ◽  
pp. 483-491 ◽  
Author(s):  
Hans Mori ◽  
D. A. Chant
Keyword(s):  
Relative Humidity ◽  
Functional Response ◽  
Tetranychus Urticae ◽  
Prey Density ◽  
Prey Species ◽  
Phytoseiulus Persimilis ◽  
Predacious Mite ◽  
Egg Consumption ◽  
Tetranychus Urticae Koch

The functional response of the predacious mite Phytoseiulus persimilis Athias-Henriot was tested at various densities of Tetranychus urticae (Koch), a prey species, and at several levels of humidity and hunger. The consumption of adult prey per predator rose at first with increasing prey density, but significantly decreased at high densities. This phenomenon was caused by an increase in abandonment of captures resulting from disturbance by other prey at high prey densities. Egg consumption by the predator increased with prey density.Prey consumption was greater at low than at high humidities. A significant increase in the rate of repeat feeding was found at higher levels of predator hunger, but the differences in consumption of prey between the three levels of hunger were not significant.

scholarly journals Functional response of Phytoseiulus persimilis Athias-Henriot to Tetranychus urticae Koch: effects of prey life stages and temperature

1970 ◽  
Vol 29 ◽  
pp. 1-8 ◽  
Author(s):  
Md Fazlul Hoque ◽  
Md Wahedul Islam ◽  
M Khalequzzaman
Keyword(s):  
Functional Response ◽  
Tetranychus Urticae ◽  
Adult Female ◽  
Prey Density ◽  
Nonlinear Least Squares ◽  
Handling Time ◽  
Phytoseiulus Persimilis ◽  
Life Stages ◽  
Least Squares Regression ◽  
Tetranychus Urticae Koch

This paper examines the effect of density and temperature on the functional response of adult female Phytoseiulus persimilis to different life stages of the spider mite, Tetranychus urticae. The functional response was determined using functional response assay technique with plant leaf discs an arena. We conducted a logistic regression of the proportion of prey consumed as a function of initial prey density to identify functional response types, and used nonlinear least-squares regression and the random predator equation to estimate attack rates and handling times. In all the cases number of adult male prey attacked by female predator were greater than adult female prey. P. persimilis consumed more eggs and larvae than other stages of prey. Female predator consumed adult prey at each temperature which generally increased with prey density initially but leveled off at higher prey densities. The highest number of eggs, larvae and nymphs consumed by predator in 24 hours was 16.3 ± 0.42, 9.9 ± 0.59 and 9.5 ± 0.40 respectively whereas the highest number of eggs, larvae and nymphs consumed by a single female in 48 hours was 19.5 ± 1.15, 18.6 ± 0.62 and 13.3 ± 0.65 respectively. Handling time generally decreased with temperature whereas successful attack rate increased with temperature except at 30º C. Judging by a/Th values, P. persimilis was most efficient against T. urticae at 30-35ºC, about half as efficient at 25 ºC and performed poorly at 20º C. Again, from a/Th values, P. persimilis was most efficient against T. urticae in egg stage, about half as efficient at larva and nymph stages and performed poorly at adult stage.   Key words: Phytoseiulus persimilis; Tetranychus urticae; functional response; predation; temperature.DOI: http://dx.doi.org/10.3329/ujzru.v29i1.9458 UJZRU 2010; 29(1): 1-8

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