Dilley, B.J., Davies, D., Glass, T., Bond, A.L., & Ryan, P.G. 2020 Severe impact of introduced scale insects on Island Trees threatens endemic finches at the Tristan da Cunha archipelago. Biological Conservation 251: 108761

Keywords:

  • distribution
  • ecology
  • Notes: Inaccessible and Nightingale Islands are uninhabited islands in the Tristan da Cunha archipelago, central South Atlantic Ocean. Over the past decade, the spread and impacts of two species of invasive scale insects have increased steadily, severely affecting the Island Tree Phylica arborea woodlands and the endemic large-billed finches Nesospiza spp., which feed extensively on Phylica fruit. Greedy Scale Hemiberlesia rapax, causes local canopy diebacks and slightly reduced fruit loads. Brown Soft Scale Coccus hesperidum and its associated sooty mould have expanded their range at Inaccessible since 2011, and colonized Nightingale by 2016. Phylica fruit loads are markedly reduced and many large trees have died.