Amensalism Via Webs Causes Unidirectional Shifts of Dominance in Spider Mite Communities.
From: Laboratory of Ecological Information, Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan. mhosaka@kais.kyoto-u.ac.jp
Oecologia
- Publish Date: Dec 2006
- ISSN: 0029-8549
- Volume: 150
- Issue: 3
- Pages: 496-505
- Medium: Print
- Language: English
- Citation (JAMA): Osakabe Masahiro, Hongo Kimiko, Funayama Ken, et al. Amensalism Via Webs Causes Unidirectional Shifts of Dominance in Spider Mite Communities.. Oecologia Dec 2006;150:496-505
Abstract
Competitive displacement is considered the most severe consequence of interspecific competition; if a superior competitor invades the habitat of an inferior species, the inferior species will be displaced. Most displacements previously reported among arthropods were caused by exotic species. The lack of investigation of displacement among native species may be due to their apparently harmonious coexistence, even if it is equivalent to an outcome of interspecific association. A seasonal change in the species composition of spider mites, from Panonychus ulmi to Tetranychus urticae, is observed in apple trees worldwide. Previous laboratory experiments have revealed amensal effects of T. urticae on P. ulmi via their webs. Using manipulation experiments in an orchard, we tested whether this seasonal change in species composition occurred as the result of interspecific competition between these spider mites. Invasion by T. urticae prevented an increase in P. ulmi densities throughout the experimental periods. Degree of overlap relative to the independent distribution on a leaf-surface basis (omega (S)) changed from positive to negative with increasing density of T. urticae. T. urticae invasion drove P. ulmi toward upper leaf surfaces (competitor-free space). The niche adjustment by P. ulmi occurred between leaf surfaces but not among leaves. Our findings show that asymmetrical competition between T. urticae and P. ulmi plays an important role in this unidirectional displacement and that the existence of refuges within a leaf produces the apparently harmonious coexistence of the mites and obscures their negative association.
Mesh Headings (Keywords): Analysis of Variance, Animals, Competitive Behavior, Ecosystem, Japan, Malus, Population Density, Population Dynamics, Seasons, Species Specificity, Tetranychidae
Check for Full Text / PubMed Unique Identifier (PMID): 17024380
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.