Biological Invasions

, Volume 18, Issue 5, pp 1235–1246

Range expansion and increasing impact of the introduced wasp Aphidiusmatricariae Haliday on sub-Antarctic Marion Island

Original Paper

DOI: 10.1007/s10530-015-0967-3

Cite this article as:
Lee, J.E. & Chown, S.L. Biol Invasions (2016) 18: 1235. doi:10.1007/s10530-015-0967-3

Abstract

Despite the significance of biological invasions in the Antarctic region, understanding of the rates of spread and impact of introduced species is limited. Such information is necessary to develop and to justify management actions. Here we quantify rates of spread and changes in impact of the introduced wasp Aphidius matricariae Haliday, which parasitizes the invasive aphid Rhopalosiphum padi (L.), on sub-Antarctic Marion Island, to which the wasp was introduced in ca. 2001. Between 2006 and 2011, the wasp had colonised all coastal sites, with an estimated rate of spread of 3–5 km year−1. Adult abundance doubled over the period, while impact, measured as mean percentage parasitism of R. padi, had increased from 6.9 to 30.1 %. Adult wasps have thermal tolerances (LT50s) of between −18 and 33.8 °C, with a crystallization temperature of −22.9 °C, and little tolerance (ca. 37 h) of low humidity at 10 °C. Desiccation intolerance is probably limiting for the adult wasps, while distribution of their aphid host likely sets ultimate distributional limits, especially towards higher elevations where R. padi is absent, despite the presence of its host grass on the island, Poa cookii (Hook. f.). Rising temperatures are benefitting P. cookii, and will probably do the same for both R. padi and A. matricariae. Our study shows that once established, spread of introduced species on the island may be rapid, emphasizing the importance of initial quarantine.

Keywords

Dispersal Hemiptera Hymenoptera Impact Physiological tolerance Spread 

Supplementary material

10530_2015_967_MOESM1_ESM.docx (19 kb)
Supplementary material 1 (docx 18 kb)

Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  1. 1.Department of Botany and Zoology, Centre for Invasion BiologyStellenbosch UniversityMatielandSouth Africa
  2. 2.School of Biological SciencesMonash UniversityVictoriaAustralia

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