Edible insects, mātauranga, diet, and lifestage to explore the potential of Aotearoa New Zealand insects as food : A thesis submitted in partial fulfilment of the requirements for the Degree of Doctor of Philosophy at Lincoln University

Abstract

With growing global concerns about food security and environmental sustainability, insects as food could provide a promising alternative protein source. However, research on entomophagy (eating insects) has predominantly focused on Western perspectives, who perceive edible insects as a novel concept, and there is limited exploration of Indigenous knowledge systems. This thesis investigates the potential of native Aotearoa New Zealand insects as sustainable and nutritious food sources, integrating mātauranga Māori (indigenous Māori knowledge) with Western scientific approaches. A survey of Māori participants (n=172) revealed that insects are culturally significant, with 47% of participants having consumed insects or knowing whānau (family) who had. Larvae of the huhu beetle (Prionoplus reticularis White, 1843) was identified as the most consumed insect, with 89% of participants naming it as a traditional food source. The survey also indicated that participants were significantly more likely to consume insects that were native to Aotearoa New Zealand, fed rākau rongoā (medicinal plants), or historically eaten by Māori (P<0.05). Most participants indicated they would eat insects either processed or whole (49%, N=78), with a total of 87% of participants indicating they would be willing to eat insects in some form (processed 37%, N=59, whole 4%, N=7). Through integration of mātauranga Māori, ecological factors, and nutritional considerations, three Lepidoptera species were selected and studied as whole insects; kawakawa looper (Cleora scriptaria (Walker, 1860)), brindled bell moth (Epalxiphora axenana Meyrick, 1881), and brown headed leafroller (Ctenopseustis obliquana (Walker, 1863)), and two culturally significant plant diets; kawakawa (Macropiper excelsum (G.Forst.) Miq.), and mānuka (Leptospermum scoparium Forst.). The selection process considered factors such as sustainability of rearing processes, life cycle length, plant associations, and cultural significance. Amino acid (AA) and mineral analysis, using high-performance liquid chromatography (HPLC) and inductively coupled plasma mass spectrometry (ICP-MS) respectively, showed that all three species met FAO/WHO requirements for essential AAs of 40%, with the essential AA to non-EAA ratios ranging from 41.1% to 44.5%. The brindled bell moth showed significantly higher levels of several minerals, including sodium, magnesium, potassium, and calcium, with iron content (21.4 mg/100g dry weight (DW)) (P<0.05) that exceeded New Zealand recommended daily intake. Diet studies with the brown headed leafroller showed that larvae and pupae reared on either mānuka or kawakawa had significantly higher levels of macrominerals, particularly sodium, magnesium, potassium, and phosphorus, compared to those on laboratory diets. Larvae reared on mānuka demonstrated higher concentrations of several essential AAs, including histidine, isoleucine, threonine, and valine, with total essential AA content (223.2 mg/g DW) significantly higher than those on laboratory diet (166.6 mg/g DW) (P<0.05). The dietary influence was more significant than life stage in determining amino acid composition. Mātauranga Māori recognises that kawakawa leaves eaten by the kawakawa looper have enhanced medicinal properties. Supporting this knowledge, metabolomic analysis using rapid evaporative ionisation MS (REIMS) revealed distinct chemical changes in leaves eaten by the kawakawa looper (444 features, 16.08% differing from non-eaten leaves). These changes were unique and specific to insect herbivory, as artificially damaged leaves showed no significant differences from control leaves. The metabolomic response also varied between species, with the kawakawa looper and brindled bell moth showing the most distinct profiles (20.79% features differing), suggesting species-specific interactions between insects and kawakawa. This research provides the first comprehensive analysis of native Aotearoa New Zealand insects as a sustainable food source, integrating mātauranga Māori and Western scientific approaches. The findings establish a foundation for developing nutritious insect-based foods that align with cultural values and environmental sustainability, demonstrating the potential of native insects in addressing food security challenges in Aotearoa New Zealand and globally.