Regional persistence of locally unstable predator/prey populations

Abstract

Nachman. G., 1988. Regional persistence of locally unstable predator/prey populations. Exp. Appl.Acarol., 5: 293-318.Phb¢oseiid mites are efficient predators capable of completely destroying colonies of spider mites. Thus, coexistence of phytoseiids and their tetranychid prey at a local scale (typically an individual plant) is not likely for more than a single predator/prey cycle. However, the species may coexist at a regional scale, i.e. in a complex environment consisting of many plants, provided local colonisations, extinctions and recolonisations occur asynchronously. This review investigates some of the factors responsible for establishing and maintaining spatial asynchrony between local populations of prey and predators, such as dispersal, environmental heterogeneity and demographic stochasticity. Existing predator/prey models are considered in order to find agreement between theory and empirical data. Based on our current knowledge of spatial processes and their importance for the overall dynamics and persistence of predator/prey interactions, some consequences and aspects for biological control of crop pests by means of natural enemies are outlined.

Local and regional dynamics of a specialist herbivore: overexploitation of a patchily distributed host plant

“…The larger and the more spatially heterogeneous a system is, the less likely it is that local dynamics will synchronise (Taylor 1988(Taylor , 1990Fahrig and Paloheimo 1988;Hanski 1991). Detailed laboratory experiments on predator/prey systems have confirmed these theories (Huffaker 1958;Nachman 1988Nachman , 1991Lawler 1996a, 1996b).…”

“…dieffenbachii system is comparable to predator/prey complexes where predators cause local extinctions of their prey (Huffaker 1958 ;Huffaker et al 1963 ;Nachman 1988Nachman , 1991Lawler 1996a, 1996b) and in which some predators do not disperse until their local prey population is extinct. McEvoy et al (1995) demonstrated that also some spatially structured biocontrol systems do not establish a stable pestenemy equilibrium at the local scale, but are locally unstable on a "search-destroy" basis.…”

Improved Carica papaya Tolerance to Carmine Spider Mite by the Expression of Manduca sexta chitinase Transgene

“…Movement of mites in a colony or patch occurs frequently, is mostly by ambulatory means, and has a low risk for mortality (Strong et al, 1999). Larger movement of mites from one isolated plant to another (interpatch) occurs less often and has more risk for mortality than intrapatch movement (Nachman, 1988). Interpatch movement is affected by many factors including temperature and humidity, wind and spatial structure of the patch, and loss of food supply (Strong et al, 1997(Strong et al, , 1999.…”

Of mites and models: an introduction to the symposium proceedings

“…This work, we believe, opened the door to a major body of research on what has become known as metapopulation dynamics, which has dominated the past decade. The various experimental and theoretical developments that led up to, and consisted of the early stages of this new era of ecological research are eloquently discussed in Nachman's (1988 ) contribution to the proceedings of the first symposium on population dynamics of plant mites (a meeting that also led to the foundation of the European Association of Acarologists).…”