Egg mortality in the pine processionary moth: habitat diversity, microclimate and predation effects
Article first published online: 1 APR 2014
© 2014 The Royal Entomological Society
Agricultural and Forest Entomology
Volume 16, Issue 3, pages 284–292, August 2014
How to Cite
Castagneyrol, B., Jactel, H., Charbonnier, Y., Barbaro, L. and Dulaurent-Mercadal, A.-M. (2014), Egg mortality in the pine processionary moth: habitat diversity, microclimate and predation effects. Agricultural and Forest Entomology, 16: 284–292. doi: 10.1111/afe.12056
- Issue published online: 15 JUL 2014
- Article first published online: 1 APR 2014
- Manuscript Accepted: 1 FEB 2014
- Manuscript Revised: 22 JAN 2014
- Manuscript Received: 7 DEC 2013
- French National Research Agency. Grant Number: ANR 07 BDIV 013-07-URTICLIM
- European Community's Seventh Framework Programme (FP7/2007–2013). Grant Number: 226299
- Associational resistance;
- hedge effect;
- natural enemies;
- pine plantations;
- Thaumetopoea pityocampa
- Little is known about the relative effect of different mortality factors triggering the population dynamics of outbreaking Lepidoptera (e.g. climate, natural enemies, habitat diversity), especially at the egg stage.
- The presence of broadleaved hedgerows bordering pine stands has been shown to reduce infestation by Thaumetopoea pityocampa (Denis & Schiffermüller, Lepidoptera). This effect of habitat diversity has been proposed to result from the disruption of visual and chemical cues that the female moth uses to locate its host. In the present study, we further hypothesized that egg mortality was higher behind broadleaved hedgerows because of higher predation or parasitism, or as a result of harsher microclimatic conditions.
- A total of 120 egg masses obtained from laboratory rearing were exposed under three exclusion treatments (large predators, predators and parasitoids, no exclusion). Overall egg mortality was 35%. Predation was the main cause of mortality (22%). Mortality as a result of abiotic factors (abortion) was only 12%. Almost no parasitoids were observed.
- Overall mortality did not differ between pines bordered (or not) by deciduous hedgerows, nor did mortality differ as a result of predation or abortion.
- Despite an important contribution of predation to mortality in T. pityocampa eggs, the effect of deciduous hedgerows on tree infestation by this pest is more likely to result from disruption of female moth behaviour than from differential mortality.