ecology of phasmids - KLUEDO - Universität Kaiserslautern

More documents

Recommendations

Info

Introduction 8 1.3.4 Data analysis For statistical analysis I used the computer-based programs Statistica (StatSoft Inc. 2001) and JMP (SAS Institute Inc. 2001). Data were processed in Excel (Microsoft Corp. 2000). Figures were created in SigmaPlot (SPSS Inc. 1999), Excel and Statistica.
Community structure & host range 9 2 Community structure and host range of phasmids on BCI 2.1 Introduction Biodiversity of tropical forests is markedly higher than in their temperate counterparts (e.g., Mac Arthur 1972; Erwin 1982) and herbivorous insects constitute a major fraction of species (Erwin 1982; Stork 1993; Ødegard 2000; Novotny et al. 2002a). The origin of tropical species diversity is partly hypothesized to be based on the arms raise between plants and their consumers. Their impact on leaves is thought to represent an important selective force for the evolution of plant defenses (Ehrlich & Raven 1964; Rhoades & Cates 1976; Coley et al. 1985). Also, herbivory on seeds and seedlings has been attributed to the high diversity of tropical plant communities (Janzen 1970; Connell 1971). In return the greater variety and higher regime of plant defenses in tropical forests are discussed to favor narrower diets of tropical insect herbivores thereby leading to a higher arthropod diversity than in temperate forests (Janzen 1973; Coley & Aide 1991). Aside from plant defenses, natural enemies can select for narrower diets since they have different abilities to locate a herbivore on variable plant species (Price et al. 1980, Bernays & Graham 1988). In contrast, the scarcity of most plant species in tropical forests (Hubbell & Foster 1986) may favor the generalist habit if locating them is difficult and costly for a specialist herbivore, both in terms of time and exposure to predators (Jaenike 1990; Basset 1992; Coley & Barone 1996). Indeed most tropical insect herbivores seem to be relatively specific. Even though the debate on the degree of host specificity remains controversial (e.g. Erwin & Scott 1980; Erwin 1982; Basset 1999; Basset et al. 1992, 1996; Barone 1998; Ødegard 2000; Novotny et al. 2002a, 2002b) there is evidence that 90 percent of all phytophagous insects feed on plants in less than three different plant families (Bernays & Graham 1988; Marquis & Braker 1994; Barone 1998). The majority of insect herbivore species in tropical forests is rare (Basset 1996, 1999; Basset et al. 1992, 1996; Barone 1998; Novotny et al. 2002b) and abundances vary temporally and spatially. In seasonal tropical forests, abundances of many insect species are positively correlated to rainfall (Wolda 1978, 1979, 1982, 1992) and leaf production (Murali & Sukumar 1993). Concerning the maintenance of low overall population densities, the relative roles of lower or higher trophic levels are subject to ongoing debate but evidence suggests that top-down effects are more important (Coley & Barone 1996; Pace et al. 1999; Persson 1999; Polis 1999; Dyer & Coley 2001). On a spatial scale insect herbivore densities are generally assumed to be higher in light gaps than in the forest understory, but this has mainly been inferred from leaf damage (e.g., Coley, 1980, 1982, 1983; Coley & Barone 1996 and references therein). Empirical studies on spatial variation in tropical insect herbivore abundances are scarce (e.g., Elton
Page 1 and 2: ECOLOGY OF PHASMIDS (PHASMATODEA) I
Page 5 and 6: ECOLOGY OF PHASMIDS (PHASMATODEA) I
Page 7 and 8: Acknowledgements I Acknowledgements
Page 9 and 10: Table of Contents III 3 Life cycle,
Page 11 and 12: List of Figures V List of Figures F
Page 13: List of Abbreviations VII List of A
Page 16 and 17: Introduction 2 Regardless whether s
Page 18 and 19: Introduction 4 Description of phasm
Page 20 and 21: Introduction 6 Solanum and Piper (T
Page 24 and 25: Community structure & host range 10
Page 46 and 47: Life history & potential population
Page 58 and 59: Adult female feeding preference & n
Page 72 and 73:
Adult female feeding preference & n
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Predation mediated mortality & migr
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 105 and 106:
Concluding remarks 91 6 Concluding
Page 107:
Abstract 93 7 Abstract Herbivory is
Page 110 and 111:
Literature cited 96 Basset, Y. 1997
Page 112 and 113:
Literature cited 98 Brown, B. J., M
Page 114 and 115:
Literature cited 100 Croat, T. B. 1
Page 116 and 117:
Literature cited 102 Hagerman, A. E
Page 118 and 119:
Literature cited 104 Kearsley, M. J
Page 120 and 121:
Literature cited 106 McNeill, S., T
Page 122 and 123:
Literature cited 108 Reich, P. B.,
Page 124 and 125:
Literature cited 110 Strong, D. R.,
Page 127:
Appendix 113 9 Appendix Please cont
Page 130 and 131:
Appendix 1: Phasmid species previou
Page 133 and 134:
Tabellarischer Lebenslauf Angaben z
Page 135:
Berger J., Schaefer, M., 1997. Wild
show all

ecology of phasmids - KLUEDO - Universität Kaiserslautern

Create successful ePaper yourself

Delete template?

Save as template?