Host growth form underlies enemy-free space for lichen-feeding moth larvae
Article first published online: 25 MAY 2011
© 2011 The Author. Journal of Animal Ecology © 2011 British Ecological Society
Journal of Animal Ecology
Volume 80, Issue 6, pages 1324–1329, November 2011
How to Cite
Pöykkö, H. (2011), Host growth form underlies enemy-free space for lichen-feeding moth larvae. Journal of Animal Ecology, 80: 1324–1329. doi: 10.1111/j.1365-2656.2011.01866.x
- Issue published online: 10 OCT 2011
- Article first published online: 25 MAY 2011
- Received 17 December 2010; accepted 28 April 2011 Handling Editor: Simon Leather
- field experiment;
- host architecture;
- host range;
- lichen growth form;
- tri-trophic interaction
1. Natural enemies may direct the host use of herbivorous insects on those hosts that ensure highest survival, thus creating enemy-free space. Host structure may contribute to enemy-free space if the current host ensures better refuge from natural enemies than other potential hosts. So far, however, direct evidence of the role of host structure for enemy-free space is lacking.
2. This study looks at the effect of physical host structure on the previously demonstrated enemy-free space of a lichen-feeding moth, Cleorodes lichenaria by manipulating the structure of host lichens and the access of natural enemies to larvae in the field. It was predicted that if larvae receive enemy-free space on Ramalina lichens because of their shrubby appearance, larvae should survive better on shrubby than on flat lichens in the presence of natural enemies but not in the absence of natural enemies.
3. Larvae survived better on shrubby than flat lichens and when the access of natural enemies to larvae was prevented than in the presence of them. According to the prediction, larvae in the presence of natural enemies survived better on shrubby compared with flat thalli but not in the absence of natural enemies. Thus, shrubby host structure promotes survival of larvae and underlies the enemy-free space on Ramalina species in natural conditions.
4. Host structure as a mechanism for enemy-free space and the direct impact of host structure for the performance of C. lichenaria larvae are discussed. Other potential reasons, such as lichen secondary chemicals and host-induced colouration of larvae as a basis of enemy-free space, are also discussed.