Nondestructive evaluation of larval development and feeding Title behavior of the bamboo powderpost beetle Dinoderus minutus in bamboo culms( Dissertation_全文 ) Author(s) Watanabe, Hiroki Citation 京都大学 Issue Date 2018-03-26 URL https://doi.org/10.14989/doctor.k21140 Right Type Thesis or Dissertation Textversion ETD Kyoto University Nondestructive evaluation of larval development and feeding behavior of the bamboo powderpost beetle Dinoderus minutus in bamboo culms Hiroki WATANABE 2018 Contents General introduction ...................................................................................................................... 1 Chapter 1. Literature review and objectives .................................................................................. 5 1.1. Introduction ........................................................................................................................ 5 1.2. Insect pests of bamboo culms in Japan ............................................................................... 5 1.3. Studies on the biology and control of D. minutus and closely related species ................... 9 1.4. Nondestructive techniques for detecting insects and insect attack in wood ..................... 11 1.5. Objectives ......................................................................................................................... 15 Chapter 2. Evaluation of larval development and feeding behavior using X-ray computed tomography ............................................................................................................. 16 2.1. Introduction ...................................................................................................................... 16 2.2. Visualization of larval growth process and tunneling process in infested bamboo culms 17 2.2.1. Materials and methods ............................................................................................... 17 2.2.2. Results and discussion on larval growth and tunneling observed in CT images ....... 19 2.3. Evaluation of individual egg-to-adult development and feeding behavior ...................... 25 2.3.1. Egg collecting ............................................................................................................ 25 2.3.2. Inoculation of larvae in bamboo and X-ray CT scanning .......................................... 27 2.3.3. Results and discussion on larval–pupal development and larval feeding .................. 30 2.3.4. Discussion on larval duration .................................................................................... 35 2.3.5. Pre-mating adult feeding ........................................................................................... 37 2.4. Summary .......................................................................................................................... 39 Chapter 3. Relationship between the movements of the mouthparts and the generation of acoustic emission .................................................................................................... 41 3.1. Introduction ...................................................................................................................... 41 3.2. Materials and methods ...................................................................................................... 42 3.2.1. Experimental insects and bamboo specimens ............................................................ 42 3.2.2. Apparatuses ............................................................................................................... 44 3.2.3. Measurement of time lags between AE signals and video signals ............................ 46 3.2.4. Analysis ..................................................................................................................... 47 3.3. Results and discussion ...................................................................................................... 48 3.3.1. Larval feeding ............................................................................................................ 48 3.3.2. Adult feeding ............................................................................................................. 55 3.4. Summary .......................................................................................................................... 57 Chapter 4. Combined use of acoustic emission and X-ray computed tomography to monitor larval feeding activity and development .................................................................. 58 4.1. Introduction ...................................................................................................................... 58 4.2. Materials and methods ...................................................................................................... 59 4.2.1. Preparation of bamboo pieces and inoculation of larvae ........................................... 59 4.2.2. AE measurement and analysis ................................................................................... 61 4.2.3. Direct observation of ecdysis and pupation (Additional experiment I) ..................... 62 4.2.4. Measurement of distance attenuation of elastic waves in bamboo (Additional experiment II) ............................................................................................................ 63 4.2.5. Measurement of amplitude of AE generated by larvae of different instars (Additional experiment III) .......................................................................................................... 64 4.2.6. Estimation of head capsule widths of all instars (Additional experiment IV) ........... 65 4.3. Results and discussion ...................................................................................................... 66 4.3.1. Feeding activity and development from the first instar to adult eclosion .................. 66 4.3.2. Effects of attenuation of AE waves ........................................................................... 74 4.3.3. Relationship between cumulative AE hits and bamboo consumption ....................... 79 4.3.4. Pre-mating adult feeding activity............................................................................... 81 4.4. Summary .......................................................................................................................... 82 Chapter 5. General discussion and future perspectives ............................................................... 84 5.1. Introduction ...................................................................................................................... 84 5.2. Novelty of monitoring using X-ray CT and AE in entomology ....................................... 84 5.3. Usefulness of X-ray CT and AE monitoring in managing D. minutus ............................. 86 5.3.1. Desirable process of IPM for bamboo materials ....................................................... 86 5.3.2. Application of X-ray CT and AE to inspection of insect attack ................................ 88 5.3.3. Application of X-ray CT and AE as laboratory analysis tools in developing control measures .................................................................................................................... 89 Summary and conclusions ........................................................................................................... 93 Acknowledgements ..................................................................................................................... 95 References ................................................................................................................................... 96 General introduction In many temperate and tropical regions of the world, bamboo species (family Poaceae: subfamily Bambusoideae) are an abundant natural resource because of their fast-growing nature (Fujii 2013, Uchimura 2005, 2009, 2012). They produce culms, in which hollow internodes are separated by diaphragms at the nodes. Bamboo culms are flexible and have highly useful mechanical properties (Fujii 2013, Uchimura 2005, 2009, 2012). For example, the tensile strengths of culms of madake, Phyllostachys bambusoides, and moso bamboo, P. edulis (syn.: P. pubescens), the two most common bamboo species in Japan, are 270% and 190%, respectively, of sugi (Cryptomeria japonica) wood, and the compression strengths of madake and moso bamboo culms are both 210% of sugi wood (Forestry and Forest Products Research Institute 2004). Bamboo culms also exhibit high machinability and desirable aesthetic qualities (Fujii 2013, Okahisa et al. 2005, Uchimura 2005, 2009, 2012). In Japan, bamboo culms have been used to make household goods, such as furniture products, tools, and utensils, and craft products, and as materials for agricultural and forestry uses (Fujii 2013, Uchimura 2005, 2009, 2012, Ueda 1963). In wooden buildings, they have also been used mainly as decorative elements and as a lathing material for clay walls (Fujii 2013, Uchimura 2005, 2009, 2012, Ueda 1963). However, primarily because of the spread of alternative materials such as plastics and metals, the demand for bamboo culms has been decreasing in Japan (Forestry Agency 2011, Uchimura 2005, 2009, 2012). For example, the production quantity and import of bamboo culms decreased by 35% and 57%, respectively, between 1998 and 2009 (Forestry Agency 2011). The decreasing demand for bamboo has led to expanding areas of bamboo forests being left abandoned, which is being