UCB Moorea Class: Biology and Geomorphology of Tropical Islands

The objective of this study was to determine if the distribution of insect species and presence of herbivory differed between native and non-native plants in the coastal region of Mo'orea, French Polynesia. Therefore, four native plant species (Barringtonia asiatica, Hibiscus tiliaceus, Terminalia catappa, Thespesia populnea) and four non-native plant species (Carica papaya, Mangifera spp., Morinda citrifolia, Musa spp.) were sampled. Each collected insect was tested for herbivory, and placed in a cup with a 2X1in. piece of undamaged leaf from the tree it was found and frequently checked for damage. Significantly greater insect species abundance was found on native plants compared to non-native plants (p=0.0431). No significant difference was found in richness (p=0.6409) or diversity (p=0.8451) between native and non-native plants. Significantly more herbivory damage was observed on the whole tree in native plants (p=0.0001). The herbivory trials found more cases of herbivory damage in non-native plants compared to native plants, 14 cases and 10 cases respectively, but more total area damaged in native plants compared to non-native plants, with 5.015% and 4.18% damage respectively. No significant differences were found between abundance and height of sampling, richness and height of sampling, or diversity and height of sampling (p=0.1108, 0.0933, and 0.07695). No significant differences were found between abundance and tree height, richness and tree height, or diversity and tree height (p=0.5305, 0.6156, 0.7805). The results show that there is more insect abundance and more herbivory damage in native plants, suggesting that generalist herbivores are feeding on non-native plants while specialist and generalist herbivores are feeding on native plants.