Current address: Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 750 07 Uppsala, Sweden.
Invading and resident defoliators in a changing climate: cold tolerance and predictions concerning extreme winter cold as a range-limiting factor
Article first published online: 25 MAY 2012
© 2012 The Authors. Ecological Entomology © 2012 The Royal Entomological Society
Volume 37, Issue 3, pages 212–220, June 2012
How to Cite
AMMUNÉT, T., KAUKORANTA, T., SAIKKONEN, K., REPO, T. and KLEMOLA, T. (2012), Invading and resident defoliators in a changing climate: cold tolerance and predictions concerning extreme winter cold as a range-limiting factor. Ecological Entomology, 37: 212–220. doi: 10.1111/j.1365-2311.2012.01358.x
- Issue published online: 25 MAY 2012
- Article first published online: 25 MAY 2012
- Accepted 27 February 2012
- Comparing populations;
- egg super cooling point (SCP);
- environmental variation;
- Erannis defoliaria;
- Operophtera fagata;
- species abundance;
- winter survival
1. Winter temperatures in northern latitudes are predicted to increase markedly as a result of ongoing climate change, thus making the invasion of new insect defoliators possible. The establishment of new outbreak pest species may have major effects on northern ecosystems that are particularly sensitive to disturbances.
2. Effects of winter minimum temperatures under field and laboratory conditions were examined and limitations by minimum temperatures on future range expansion were investigated for invasive [Operophtera brumata (Lepidoptera: Geometridae)] and potentially invasive [Agriopis aurantiaria (Lepidoptera: Geometridae)] birch-feeding forest pests. The results for the studied invasive and potentially invasive moths were compared with the parameters of the resident moth species Epirrita autumnata (Lepidoptera: Geometridae).
3. The results showed tolerated critical temperatures of the invader (O. brumata) and the resident (E. autumnata) were more similar (differing only by 1 °C), whereas the potential invader (A. aurantiaria) was much less tolerant of cold temperatures. Although describing different stages of overwintering, results were consistent between laboratory and field studies except for those at one field location, at which other abiotic conditions are suggested to have significant influence on moth egg survival.
4. Based on the present results and expected changes in winter temperatures over the next 30 years, the range expansion of an established invasive species may be predicted. No limitations were found regarding the possible future invasion of a new pest species to northern Fennoscandia. The importance of studying a species' whole overwintering period is highlighted and further studies devoted to the effects of other abiotic factors in addition to the effects of temperature are suggested.