ecology of phasmids - KLUEDO - Universität Kaiserslautern

Table of Contents III
3 Life cycle, potential population growth, and egg hatching failure of
Metriophasma diocles .............................................................................................................31
3.1 Introduction .......................................................................................................................31
3.2 Materials and methods ......................................................................................................33
3.2.1 Assessing demographic population parameters and life history traits.................................... 33
3.2.2 Modeling potential population growth and the effect of limited hatching success................. 35
3.3 Results ...............................................................................................................................36
3.3.1 Demographic population parameters and life history traits.................................................... 36
3.3.2 Potential population growth and effects of limited hatching success ..................................... 39
3.4 Discussion .........................................................................................................................40
3.4.1 Demographic population parameters and life history traits.................................................... 40
3.4.2 The biotic potential of Metriophasma diocles ........................................................................ 41
3.4.3 A first insight into M. diocles population control ................................................................... 42
3.4.4 Conclusions............................................................................................................................. 43
4 Preference of female adults and performance of larval stages of M. diocles on single food
plant species ............................................................................................................................44
4.1 Introduction .......................................................................................................................44
4.2 Materials and methods ......................................................................................................47
4.2.1 Measuring leaf traits ............................................................................................................... 48
4.2.1.1 Measuring leaf toughness ................................................................................... 48
4.2.1.2 Leaf phenol and tannin content........................................................................... 48
4.2.2 Dual-choice feeding trials with M. diocles adult females....................................................... 49
4.2.3 Problems inherent with dual-choice feeding trials.................................................................. 50
4.2.3.1 Conditioning due to prior feeding experience..................................................... 50
4.2.3.2 Choice of reference plant species ....................................................................... 51
4.2.4 Long term feeding trials with M. diocles nymphs .................................................................. 52
4.2.5 Dual-choice feeding trials with M. diocles nymphs................................................................ 52
4.3 Data analysis .....................................................................................................................53
4.3.1 Analysis of preference ............................................................................................................ 54
4.3.2 Analysis of performance......................................................................................................... 54
4.4 Results ...............................................................................................................................55
4.4.1 Interspecific differences in physical and chemical leaf properties ......................................... 55
4.4.2 Preference of M. diocles adult females ................................................................................... 60
4.4.3 Performance of M. diocles nymphs ........................................................................................ 62
4.4.4 Preference of M. diocles nymphs under varying total phenol and tannin contents................. 67