title: The Diet and Nutritional Ecology of the Auckland Tree Wētā Hemideina thoracica

authors: Brown, Matthew

subjects: Wētā

abstract: Insects are the main consumers of primary production in many terrestrial ecosystems, they are involved in the upwards migration of energy to higher trophic levels, and are often extremely important in structuring their ecosystems. Despite the many important ways that insects influence their ecosystems, many of the most basic aspects of the functional ecology of many groups of insects have not been investigated, and a great deal remains to be learned about what roles they play in the structure and functioning of their ecosystems. This study focuses on the Auckland tree wētā Hemideina thoracica (Orthoptera: Anostostomatidae, White, 1842), the most widespread species of tree wētā in the North Island of New Zealand, and one of the least studied species in the genus Hemideina. 
Faecal fragment analysis revealed that the diet of a population of Hemideina thoracica from a mixed podocarp/broadleaf forest was composed primarily of the leaves, fruits, and seeds, of the native plants Prumnopitys taxifolia, Podocarpus totara, Dacrycarpus dacrydioides,  Kunzia ericoides,  Melicytus sp., Pennantia corymbosa, and Coprosma rotundifolia, but the consumption of other invertebrates was also common, and formed a smaller component of the overall diet. Hemideina thoracica were also shown to feed selectively while foraging. It was determined that some plants were eaten readily by the wētā when encountered, while other plants that were equally abundant were either not consumed, or were consumed far less than would be predicted by their availability. Performing a solvent extraction, using hexane, revealed that the concentration of lipids and oils in the leaves of preferred plant species was higher than in the leaves of non-preferred species, and Hemideina thoracica may preferentially consume plants that have high lipid concentrations in their leaves. It also appeared probable that they forage on the forest floor more frequently than has been previously recognised. 
	A nutritional analysis performed in captivity revealed that H. thoracica are capable of balancing their consumption of the macronutrients protein and carbohydrates to construct an optimal diet from one or more sub-optimal sources, and strongly regulate their consumption of protein. When presented with the opportunity to construct their own diet, they consumed significantly more carbohydrates than protein, and constructed a diet with a mean protein to carbohydrate ratio of 27:73. They digested carbohydrates more efficiently than protein, but converted the protein that they consumed into biomass with a very high level of conversion efficiency. These results supported the results of the fragment analysis by demonstrating that the natural, optimal diet of H. thoracica is most likely composed of carbohydrate rich foods, but they may also be naturally omnivorous, as they utilise protein very efficiently. 
	The third, and final experiment, investigated whether H. thoracica feed on fruit in a manner that may facilitate seed dispersal for native plants in the wild. This experiment involved feeding fruit from three different native plants, Coprosma repens, Cordyline australis, and Fuchsia procumbens to a group of 40 H. thoracica, and revealed that H. thoracica frequently consume the flesh of the berry from around the seed, without ingesting the seeds themselves. When the seeds were consumed, 100 % of them were destroyed by the wētās digestive process, even in the case of very small and numerous seeds, like those of F. procumbens. It is therefore highly unlikely that H. thoracica is a seed dispersing plant-mutualist, as the seeds are either left where the fruit had fallen, or are destroyed. 
	The combined results of these studies demonstrated that Hemideina thoracica is an omnivorous polyphage, and their wild diet is composed primarily of leaves, fruits, and seeds, and the concentration of lipids and oils in the leaves appears to be an important cue in determining the palatability of different species. They are also naturally omnivorous, and protein derived from eating other insects is a common component of their overall diet They have a well developed ability to balance their consumption of protein and carbohydrates, and self-select a carbohydrate rich diet in captivity. It is also extremely unlikely that that H. thoracica act as seed dispersers for native, fruit producing plants.

text: The Diet and Nutritional Ecology of the Auckland Tree Wētā Hemideina thoracica Insects are the main consumers of primary production in many terrestrial ecosystems, they are involved in the upwards migration of energy to higher trophic levels, and are often extremely important in structuring their ecosystems. Despite the many important ways that insects influence their ecosystems, many of the most basic aspects of the functional ecology of many groups of insects have not been investigated, and a great deal remains to be learned about what roles they play in the structure and functioning of their ecosystems. This study focuses on the Auckland tree wētā Hemideina thoracica (Orthoptera: Anostostomatidae, White, 1842), the most widespread species of tree wētā in the North Island of New Zealand, and one of the least studied species in the genus Hemideina. 
Faecal fragment analysis revealed that the diet of a population of Hemideina thoracica from a mixed podocarp/broadleaf forest was composed primarily of the leaves, fruits, and seeds, of the native plants Prumnopitys taxifolia, Podocarpus totara, Dacrycarpus dacrydioides,  Kunzia ericoides,  Melicytus sp., Pennantia corymbosa, and Coprosma rotundifolia, but the consumption of other invertebrates was also common, and formed a smaller component of the overall diet. Hemideina thoracica were also shown to feed selectively while foraging. It was determined that some plants were eaten readily by the wētā when encountered, while other plants that were equally abundant were either not consumed, or were consumed far less than would be predicted by their availability. Performing a solvent extraction, using hexane, revealed that the concentration of lipids and oils in the leaves of preferred plant species was higher than in the leaves of non-preferred species, and Hemideina thoracica may preferentially consume plants that have high lipid concentrations in their leaves. It also appeared probable that they forage on the forest floor more frequently than has been previously recognised. 
	A nutritional analysis performed in captivity revealed that H. thoracica are capable of balancing their consumption of the macronutrients protein and carbohydrates to construct an optimal diet from one or more sub-optimal sources, and strongly regulate their consumption of protein. When presented with the opportunity to construct their own diet, they consumed significantly more carbohydrates than protein, and constructed a diet with a mean protein to carbohydrate ratio of 27:73. They digested carbohydrates more efficiently than protein, but converted the protein that they consumed into biomass with a very high level of conversion efficiency. These results supported the results of the fragment analysis by demonstrating that the natural, optimal diet of H. thoracica is most likely composed of carbohydrate rich foods, but they may also be naturally omnivorous, as they utilise protein very efficiently. 
	The third, and final experiment, investigated whether H. thoracica feed on fruit in a manner that may facilitate seed dispersal for native plants in the wild. This experiment involved feeding fruit from three different native plants, Coprosma repens, Cordyline australis, and Fuchsia procumbens to a group of 40 H. thoracica, and revealed that H. thoracica frequently consume the flesh of the berry from around the seed, without ingesting the seeds themselves. When the seeds were consumed, 100 % of them were destroyed by the wētās digestive process, even in the case of very small and numerous seeds, like those of F. procumbens. It is therefore highly unlikely that H. thoracica is a seed dispersing plant-mutualist, as the seeds are either left where the fruit had fallen, or are destroyed. 
	The combined results of these studies demonstrated that Hemideina thoracica is an omnivorous polyphage, and their wild diet is composed primarily of leaves, fruits, and seeds, and the concentration of lipids and oils in the leaves appears to be an important cue in determining the palatability of different species. They are also naturally omnivorous, and protein derived from eating other insects is a common component of their overall diet They have a well developed ability to balance their consumption of protein and carbohydrates, and self-select a carbohydrate rich diet in captivity. It is also extremely unlikely that that H. thoracica act as seed dispersers for native, fruit producing plants.

year: 2013

title: Recovery and Purification of Titanium Dioxide and Aluminium Compounds from Corundum By-product of the TiPro Process

authors: Jennings, Philip Anthony Charles

subjects: Aluminium

abstract: The TiPro process developed at the University of Waikato utilises an aluminothermic reaction to create titanium rich intermetallic alloys or alloy powders by solid-liquid separation. The product is then reduced with calcium vapour or calcium hydride to lower the oxygen content. This process involves intimately mixing titanium oxide powder with stoichiometric quantities of aluminium powder and heating the mixture to initiate a thermite reaction that transfers oxygen from the titanium oxide to the aluminium to produce titanium aluminide alloy and aluminium oxide. The liquid alloy is drained off from the by-product, called corundum, before going on to further processing. The corundum is left behind and contains significant quantities of valuable titanium alloy and aluminium and titanium oxides which must be recovered to increase the efficiency and lower the cost of the process.
	This thesis describes and explains proof-of-concept wet chemistry methods of processing the corundum by-product to recover and separate the valuable metal oxides. Using acid-base equilibria, over 90% of the titanium was recovered from the corundum phase as impure titanium oxide. Aluminium was recovered as aluminium hydroxide and aluminium oxide, both of which can be processed into feedstock for fresh aluminium smelting and hence represent a potential revenue stream. The products were characterised using SEM-EDX and XRD to determine their composition and structure. The proposed treatment produces no waste other than environmentally benign neutral salt water.

text: Recovery and Purification of Titanium Dioxide and Aluminium Compounds from Corundum By-product of the TiPro Process The TiPro process developed at the University of Waikato utilises an aluminothermic reaction to create titanium rich intermetallic alloys or alloy powders by solid-liquid separation. The product is then reduced with calcium vapour or calcium hydride to lower the oxygen content. This process involves intimately mixing titanium oxide powder with stoichiometric quantities of aluminium powder and heating the mixture to initiate a thermite reaction that transfers oxygen from the titanium oxide to the aluminium to produce titanium aluminide alloy and aluminium oxide. The liquid alloy is drained off from the by-product, called corundum, before going on to further processing. The corundum is left behind and contains significant quantities of valuable titanium alloy and aluminium and titanium oxides which must be recovered to increase the efficiency and lower the cost of the process.
	This thesis describes and explains proof-of-concept wet chemistry methods of processing the corundum by-product to recover and separate the valuable metal oxides. Using acid-base equilibria, over 90% of the titanium was recovered from the corundum phase as impure titanium oxide. Aluminium was recovered as aluminium hydroxide and aluminium oxide, both of which can be processed into feedstock for fresh aluminium smelting and hence represent a potential revenue stream. The products were characterised using SEM-EDX and XRD to determine their composition and structure. The proposed treatment produces no waste other than environmentally benign neutral salt water.

year: 2013

title: Te ahunga atu ki ngā ōhanga oranga Māori: Towards Māori economies of wellbeing - Ngā whānau i te pokapū o te oranga

authors: Spiller, Chellie

abstract: Nau mai ki tēnei kohinga o ngā whakaaro me ngā tikanga e pā ana ki te oranga ohaoha Māori. Ko tō mātou kaupapa matua ko te whānau; e hiahia ana mātou ki te whakaatu i ngā huarahi ki te ora pai mō te whānau i roto i ngā horopaki ohaoha. Ko te ao Māori tō mātou tūāpapa. E whakakao ana tēnei pukapuka i te huhua o ngā reo me ngā tirohanga nō te ao Māori, me ētahi atu wheako e hāngai ana. Kua kotahi mātou ki raro i te taumarumaru o te kaupapa tūturu kotahi: arā, te oranga pai mō ngā whānau. Ko te tūmanako ka tautoko, ka whakaohooho anō hoki tēnei pukapuka i ngā tāngata kia hōhonu atu tā rātou hono ki tēnei kaupapa whaitake, kia whai māramatanga whaihua hoki rātou.

Welcome to this collection of thoughts and practices related to Māori economic life. Our primary focus is the whānau; we want to show ways to live well for the whānau in economic contexts. Our foundation is te ao Māori. This book brings together many voices and perspectives from the Māori world and other relevant experiences. We are united in one true purpose: the good livelihood of whānau. We hope this book will support and inspire people to connect more deeply with this critical topic and gain valuable insights.

text: Te ahunga atu ki ngā ōhanga oranga Māori: Towards Māori economies of wellbeing - Ngā whānau i te pokapū o te oranga Nau mai ki tēnei kohinga o ngā whakaaro me ngā tikanga e pā ana ki te oranga ohaoha Māori. Ko tō mātou kaupapa matua ko te whānau; e hiahia ana mātou ki te whakaatu i ngā huarahi ki te ora pai mō te whānau i roto i ngā horopaki ohaoha. Ko te ao Māori tō mātou tūāpapa. E whakakao ana tēnei pukapuka i te huhua o ngā reo me ngā tirohanga nō te ao Māori, me ētahi atu wheako e hāngai ana. Kua kotahi mātou ki raro i te taumarumaru o te kaupapa tūturu kotahi: arā, te oranga pai mō ngā whānau. Ko te tūmanako ka tautoko, ka whakaohooho anō hoki tēnei pukapuka i ngā tāngata kia hōhonu atu tā rātou hono ki tēnei kaupapa whaitake, kia whai māramatanga whaihua hoki rātou.

Welcome to this collection of thoughts and practices related to Māori economic life. Our primary focus is the whānau; we want to show ways to live well for the whānau in economic contexts. Our foundation is te ao Māori. This book brings together many voices and perspectives from the Māori world and other relevant experiences. We are united in one true purpose: the good livelihood of whānau. We hope this book will support and inspire people to connect more deeply with this critical topic and gain valuable insights.

year: 2025