Adaptive radiation through phenological shift: the importance of the temporal niche in species diversification
Article first published online: 7 OCT 2008
© 2008 The Authors Journal compilation © 2008 The Royal Entomological Society
Volume 34, Issue 1, pages 81–89, February 2009
How to Cite
SACHET, J.-M., PONCET, B., ROQUES, A. and DESPRÉS, L. (2009), Adaptive radiation through phenological shift: the importance of the temporal niche in species diversification. Ecological Entomology, 34: 81–89. doi: 10.1111/j.1365-2311.2008.01045.x
- Issue published online: 14 JAN 2009
- Article first published online: 7 OCT 2008
- Accepted 10 June 2008First published online 7 October 2008
- character displacement;
- isolation by time;
- larch cone flies;
- seed predators;
Abstract 1. Phenological shift in oviposition in seed predators may be a key factor for adaptive radiation if temporal differences lead to less intense competition.
2. This hypothesis was tested at two sites in the French Alps in three sympatric species of larch cone flies grouped into two phenological groups (early and late) differing in adult emergence and oviposition timing by approximately 2 weeks. The present study assessed the intensity of competition within and between groups by measuring four larval traits. Cone traits were measured, and the impact of early species parasitism on cone development was assessed.
3. The occupation of the central axis of a developing cone by one early larva has a strong detrimental effect on cone growth and seed production. However, there was almost no correlation between the variables measured on the cones and on the larvae, suggesting that the resources available were not limiting.
4. Inter-group competition had no significant effect on early larvae. In contrast, both inter- and intra-group competition had a significant negative effect on late larvae length (–11% and –16% respectively), dry mass (–8% and –23%), and lipid mass (–15% and –26%). The intensity of competition was stronger among larvae in the same phenological group, which is consistent with the hypothesis that shifts in oviposition promote adaptive radiation in larch cone flies by reducing competition among larvae.