Phoenix Group

Evolutionary Ecology & Genetics

Mari Nakano
I am interested in the ecology and evolution of insects. I came to New Zealand in 2011 to study undergraduate degree in Zoology, and majored ecology for my Master’s degree. For my MSc project, I studied New Zealand stick insect Clitarchus hookeri, in which I compared the chemical and morphological traits between sexual and asexual populations that can be involved in male choice.

My Ph.D. project is about investigating the mechanisms of co-occurrence in the three New Zealand alpine grasshopper species, Brachaspis nivalis, Sigaus australis and Paprides nitidus, by exploring their species- and sex-specific feeding patterns, chemical and morphological adaptations to their food, and sexual communication systems.

PhD research
New Zealand’s indigenous grasslands are home to 16 endemic grasshopper species. At some high elevation locations four grasshopper species co-occur at high densities. These alpine grasshoppers occur in open tussock and herbfields, areas that are dominated by native plant species. Endemic grasshoppers are known to have significant impact on the grassland vegetation above 1200m and might be important determinants of community composition (ecosystem architects). This is because although these grasshoppers are dietary generalists, they show preference for some endemic plant species that have low productivity (long-lived and slow growing). The impact of grasshopper grazing on the endemic alpine plants represents an important ecological interaction in alpine grasslands and understanding this plant-insect interaction is therefore important in the conservation and sustainable management of these systems.

Variation in mandibular traits between Brachaspis nivalis (left), Sigaus australis (middle) and Paprides nitidus (right). Difference in teeth length and melanized area may reflect adaptation to plants that have different size and toughness.

Photos of chemo-receptive sensilla (sensory organs) on alpine grasshoppers’ antennae. Five morphological types found: one responsible for taste reception and four other types responsible for smell reception.

Academic Publications
Nakano M, Morgan-Richards M, Godfrey AJR, Clavijo McCormick A. 2019. Parthenogenetic females of the stick insect Clitarchus hookeri maintain sexual traits. Insects 10, 202; doi:10.3390/insects10070202