Odyssey of stow-away noctuid moths to southern polar islands

Abstract

High southern latitude island environments are unusual in having relatively low or, in some cases, no non-indigenous species (NIS). Here we describe the accidental transport and survivorship of moths (Lepidoptera, Noctuidae) on a research vessel travelling from southern South America (Montevideo, Uruguay) first to the cool temperate Falkland Islands and then onwards to Maritime Antarctic Signy Island (South Orkney Islands). On the vessel's arrival at Stanley, Falkland Islands, from Montevideo we found eight live (and 30 dead) individuals of two species of South American noctuid moth (Pseudaletia adultera Schaus and Peridroma saucia (Hübner)), presumed to have been attracted to the ship's lights while in port. Neither of these is indigenous to the Falkland Islands. Five of the eight living moths (all P. adultera) survived the four days the ship was moored in Stanley and one survived a further four day journey across the Polar Front to Signy Island. Southern oceanic islands are particularly vulnerable to invasion by NIS, with human (shipping) activities being the main route of arrival. With increasing shipping throughout this region some measures have been proposed or adopted to reduce the risk of NIS transfer.