Influence of spatial heterogeneity and prey density on predatory behaviour of the tropical spidersCyrtophora cicatrosa (Stoliczka) andMarpissa calcutaensis (Tikader) (Araneae, Araneidae)

1983 ◽  
Vol 92 (6) ◽  
pp. 429-435 ◽  
Author(s):  
S Palanichamy
Keyword(s):  
Spatial Heterogeneity ◽  
Prey Density ◽  
Predatory Behaviour

scholarly journals Experimental evolution of a microbial predator's ability to find prey

2008 ◽  
Vol 276 (1656) ◽  
pp. 459-467 ◽  
Author(s):  
Kristina L Hillesland ◽  
Gregory J Velicer ◽  
Richard E Lenski
Keyword(s):  
Escherichia Coli ◽  
Experimental Evolution ◽  
Prey Density ◽  
Myxococcus Xanthus ◽  
Foraging Theory ◽  
High Density ◽  
Fruiting Bodies ◽  
Predatory Behaviour ◽  
Handling Performance

Foraging theory seeks to explain how the distribution and abundance of prey influence the evolution of predatory behaviour, including the allocation of effort to searching for prey and handling them after they are found. While experiments have shown that many predators alter their behaviour phenotypically within individual lifetimes, few have examined the actual evolution of predatory behaviour in light of this theory. Here, we test the effects of prey density on the evolution of a predator's searching and handling behaviours using a bacterial predator, Myxococcus xanthus . Sixteen predator populations evolved for almost a year on agar surfaces containing patches of Escherichia coli prey at low or high density. Improvements in searching rate were significantly greater in those predators that evolved at low prey density. Handling performance also improved in some predator populations, but prey density did not significantly affect the magnitude of these gains. As the predators evolved greater foraging proficiency, their capacity diminished to produce fruiting bodies that enable them to survive prolonged periods of starvation. More generally, these results demonstrate that predators evolve behaviours that reflect at least some of the opportunities and limitations imposed by the distribution and abundance of their prey.

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.

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.

Invertebrate prey and predatory behaviour of the omnivorous African tortoise Kinixys spekii

2001 ◽  
Vol 39 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Adrian Hailey ◽  
Ian M. Coulson ◽  
Tarombera Mwabvu
Keyword(s):  
Predatory Behaviour ◽  
Invertebrate Prey

Soil Spatial Heterogeneity and Systems of Agriculture

2015 ◽  
Vol 2 (1) ◽  
pp. 50-59
Author(s):  
V. Medvedev
Keyword(s):  
Spatial Heterogeneity ◽  
Soil Cover ◽  
Regular Grid ◽  
Resource Saving ◽  
The Third ◽  
Soil Spatial Heterogeneity ◽  
Agriculture Systems ◽  
Zonal Soils

Aim. To consider soil continuality and discreteness as features of heterogeneity manifestation in a soil cover, important for construction of agriculture systems. Methods. Geostatistical research of soil spatial heterogeneity, revealing the contours of a fi eld with various parameters of fertility. Results. The use of principles of precise agriculture and inspection of indicative properties of fi eld soils using a regular grid allowed to divide a fi eld into contours with three levels of fertility: the fi rst one is characterized by optimal or close to optimum properties which allows refusing from (or reducing substantially) tillage, introduction of fertilizers or chemical ameliorates; the second one has average parameters of fertility corresponding to zonal soils and demands the application of zonal technologies; the third one (with the worst parameters of fertility) presupposes regular use of the improved technologies. Conclusions. The introduction of precise agriculture will allow replacing a traditional zonal system with thenew which is soil-protecting and resource-saving one.

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