Published online by Cambridge University Press: 22 August 2012
Synchrony between herbivore and host phenology can be an important factor in herbivore fitness. The survival of first-instar forest tent caterpillar (FTC) (Malacosoma disstria Hübner; Lepidoptera: Lasiocampidae) larvae and performance of surviving larvae are reduced when egg hatch and host budbreak are asynchronous. Budbreak in trembling aspen (Populus tremuloides Michaux; Salicaceae) and largetooth aspen (Populus grandidentata Michaux; Salicaceae), two preferred hosts of FTC, differ by ∼14 days. We examined the phenological requirements of FTC egg hatch to see if an inherent difference exists between FTC egg masses on the two hosts, and if the difference would promote synchrony with each host. Egg masses from a haphazard selection of clones of each host were collected in a mixed stand of trembling and largetooth aspen in New Brunswick, Canada. Egg masses were subjected to controlled temperature regimes in the laboratory, and hatch was monitored daily. Despite the differences in host phenologies and the obvious benefits of being synchronised with host phenology, egg masses collected from trembling aspen began hatching only 3 days earlier, and completed hatching only 2 days earlier, than egg masses collected from largetooth aspen. Bet hedging is discussed as a possible strategy to explain the absence of host-specific synchrony between egg hatch of FTC and the hosts it selects for oviposition.
Des masses d’œufs de livrée des forêts (Malacosoma disstria Hübner; Lepidoptera: Lasiocampidae) ont été recueillies sur des peupliers faux-trembles et des peupliers à grandes dents dans un peuplement mélangé de l'ouest du Nouveau-Brunswick, au Canada. Ces masses d’œufs ont été soumises à des régimes de température contrôlée en laboratoire, et une surveillance a été exercée quotidiennement afin d’établir le moment de l’éclosion. La phénologie du débourrement des deux hôtes diffère d'environ 14 jours, et des effets négatifs ont été observés chez les chenilles obligées de se nourrir de feuillage plus âgé. Toutefois, en dépit des différences liées à la phénologie des hôtes et des avantages évidents découlant de la synchronisation de l’éclosion avec la phénologie des hôtes, les masses d’œufs recueillies sur le peuplier faux-tremble (Populus tremuloides Michaux; Salicaceae) ont commencé à éclore trois jours avant, et avaient toutes éclos seulement deux jours avant celles récoltées sur le peuplier à grandes dents (Populus grandidentata Michaux; Salicaceae). La stratégie de minimisation des risques (bet hedging) apparaît comme une explication possible à l'absence de synchronisation spécifique à l'hôte entre l’éclosion des œufs de la livrée et la phénologie du débourrement de l'hôte sur laquelle les femelles déposent leurs œufs.
Retired.
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.
To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.