page_title: Hadramphus spinipennis
section_title: Ecology
hierarchical_section_title: Hadramphus spinipennis / Ecology
caption_attribution_description: English: Coxella weevil on Mangere Island
context_page_description: Hadramphus spinipennis, commonly called the coxella weevil, is a large, nocturnal, flightless weevil only found on Mangere and Rangatira Islands in the Chatham Islands, New Zealand.
context_section_description: This weevil's host plant is Aciphylla dieffenbachii Kirk (coxella or Dieffenbach's speargrass), a soft-leaved relative of the spine-bearing alpine Aciphylla of the New Zealand mainland. Adults make a characteristic oval feeding notch on the leaf petiole, sometimes scraping away the leaf to encourage to production of gum. Green seeds and flowers of coxella are eaten, with a preference for male flowers. Leaves are also gummed together to shelter a feeding larva, but larve also feed in the crown of the plant amongst leaf bases, and if several are present they can kill the plant.
  Because they sometimes kill their host plants, adult weevils are able to walk considerable distances—up to 600 m—in search of new patches of coxella. They seem to form a metapopulation, relying on the constant re-establishment of new patches of Aciphylla after old patches are wiped out by high weevil densities. Coxella weevils are also regularly found on Chatham Island lancewood (Pseudopanax chathamicum), on which they seem to shelter but only intermittently eat.
caption: Coxella weevil on Mangere Island
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