Seasonal, altitudinal and host plant-related variation in the abundance of aphids (Insecta, Hemiptera) on sub-Antarctic Marion Island

• Published in: Polar Biology
• Main Authors: Abraham, S., Somers, M. J., Chown, S. L.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer 2011
• Subjects: Abundance; Herbivory; Microclimate; Phenology; Sap-sucking; Antarctic; Southern Ocean; Antarc*; Antarctica; Marion Island; Polar Biology; South African National Antarctic Programme
• Online Access: http://hdl.handle.net/10019.1/113762; https://doi.org/10.1007/s00300-010-0905-x

CITATION: Abraham, S., Somers, M.J. & Chown, S.L. 2011. Seasonal, altitudinal and host plant-related variation in the abundance of aphids (Insecta, Hemiptera) on sub-Antarctic Marion Island. Polar Biology, 34(4):513–520. doi:10.1007/s00300-010-0905-x The original publication is available at https://www.springer.com/journal/300 Although aphids are the most species-rich group of invasive alien insects across the Southern Ocean Islands, their biology on the islands is poorly known. In this study, host plant-related, seasonal and altitudinal variation in the abundance of the three aphid species (Macrosiphum euphorbiae, Myzus ascalonicus, Rhopalosiphum padi)found on sub-Antarctic Marion Island is examined. Myzus ascalonicus is the most abundant of the species, reaching densities of c. 2,400 individuals per 1,200 cm2 on the indigenous Acaena magellanica (Rosaceae) and 479 individuals per 1,200 cm2 on the indigenous Cotula plumosa (Asteraceae), with lower numbers at elevations up to 300 m and a pronounced seasonal peak in December-February. Macrosiphum euphorbiae occurs on the same plant species in densities of between c. 11 individuals per 1,200 cm2 on C. plumosa and c. 200 individuals per 1,200 cm2 on A. magellanica, and with a pronounced summer peak in December. In both species, small numbers of winged forms are found (c. 1–5%), although they are permanently parthenogenetic on the island. Rhopalosiphum padi is also permanently parthenogenetic on the island and likewise shows a December peak in abundance. The current data suggest that low ambient temperatures, which are close to the lower development threshold of R. padi, and other temperate aphid species, limit development in winter, thus leading to a decline in abundance. Field work by SA and MJS was supported by a USAID grant to SLC and by the South African Department of Environmental Afairs and Tourism. SLC was partly supported by SANAP Grant SNA2007042400003. The South African National Antarctic Programme provided logistic support. This work forms a contribution to the SCAR Programme Evolution and Biodiversity in Antarctica.