Effects of host-plant shift on immune and other key life-history traits of an eruptive Geometrid, Epirrita autumnata (Borkhausen)
Article first published online: 30 APR 2008
© 2008 The Authors Journal compilation © 2008 The Royal Entomological Society
Volume 33, Issue 4, pages 510–516, August 2008
How to Cite
YANG, S., RUUHOLA, T., HAVIOLA, S. and RANTALA, M. J. (2008), Effects of host-plant shift on immune and other key life-history traits of an eruptive Geometrid, Epirrita autumnata (Borkhausen). Ecological Entomology, 33: 510–516. doi: 10.1111/j.1365-2311.2008.01000.x
- Issue published online: 8 JUL 2008
- Article first published online: 30 APR 2008
- Accepted 19 January 2008First published online 30 April 2008
- Autumnal moth;
- host plant;
- life-history traits;
- mountain birch;
Abstract 1. Population density of Epirrita autumnata (Lepidoptera: Geometridae) reaches outbreak densities regularly in northernmost Scandinavia. During these outbreak years, the most abundant host species, the mountain birch (Betula pubescens ssp. czerepanovii), is regularly exhausted, although larvae may rescue themselves from starvation by using alternative host species.
2. In this paper, the effects of the shift of host species on the immune defence and other life-history traits of E. autumnata were investigated, and possible consequences for population dynamics were briefly discussed. Moth larvae were reared on the leaves of the main host, mountain birch, until larvae reached their third instar. After this, larvae were allocated randomly to five treatments: larvae were either allowed to finish larval stage on the mountain birch or were shifted onto four alternative host species that are typical species for the area.
3. As expected, the host species had a major effect on fitness traits: body weight, development, and survival rate of the moths. The pupal weight was lower and development rates slower on the three alternative host species, Salix myrsinifolia Salisb., Vaccinium uliginosum L., and Betula nana L., than on the main host, mountain birch.
4. The immunity was, however, the same or better on the alternative hosts than on the main host. The immunity and pupal weights were negatively related, suggesting a trade-off between body size and immunocompetence.
5. The decreased body size and fecundity of E. autumnata during outbreak years may be partly due to the shift to alternative host species whereas the host-plant species probably does not affect markedly the rate of parasitism.