Ecological interactions in a changing world

Host Use 

The high host specificity of plant feeding insects and the propensity of plant feeding insect lineages to feed on closely related plants provide ideal model systems to study species interactions. In addition, considerable research has been conducted in these systems that provide considerable background information to study the mechanisms of how host-parasite interactions evolve. We tend to focus on understanding the evolution of traits associated with host use and foraging behavior, with a particular interest in how novel environmental conditions can alter species interactions. 

Climate change and species boundaries

Although not a current focus, I maintain a strong interest in the impact of climate change on species interactions. Previous work focused on how climate change has impacted the interactions between hybridizing butterfly species (including incipient speciation). 

Selected Publications (Please contact me for reprints):

Breitkreutz B., TLE Wagner, and RJ Mercader.2021. Influence of age on decision making by ovipositing Pieris rapae (Lepidoptera: Pieridae). The Great Lakes Entomologist. 54(1):4. 

Bergeron, P.E, S.J. Clary, and R.J. Mercader. 2019. Influence of host use on the dispersal propensity of Callosobruchus maculatus. Journal of applied entomology 143: 693-698.

Ording, G.J., R.J., Mercader, M.L. Aardema, and J.M. Scriber. 2010. Allochronic isolation and incipient hybrid speciation in tiger swallowtail butterflies. Oecologia 162(2): 523-531.

Mercader, R.J., M.L. Aardema, and J.M. Scriber. 2009. Hybridization leads to host use divergence in a polyphagous butterfly sibling species pair. Oecologia 158(4): 651-662.

Mercader, R.J. and J.M. Scriber. 2008. Asymmetrical thermal constraints on the parapatric species boundaries of two widespread generalist butterflies. Ecological Entomology 33(4): 537-545.

Scriber, J.M., G.J. Ording, and R.J. Mercader. 2008. Introgression and parapatric speciation in a hybrid zone. In K. Tilmon (ed.) Specialization, Speciation, and Radiation: The Evolutionary Biology of Herbivorous Insects. University of California Press, Berkley, CA. 

Mercader, R.J. and J.M. Scriber. 2008 Divergence of Ovipositional Behavior in the Papilio glaucus Group. Insect Science 15(4): 361-367.

Mercader, R.J., L.L. Stelinski, and J.M. Scriber. 2008. Differential antennal sensitivities of the generalist butterflies Papilio glaucus and Papilio canadensis to host plant and non-host plant extracts. Journal of the Lepidopterists’ Society 62(2): 84-88.

Mercader, R.J. and J.M. Scriber. 2007. Diversification of Host Use in Two Polyphagous Butterflies: Differences in Oviposition Specificity or Host Rank Hierarchy? Entomologia Experimentalis et Applicata 125(1): 89-101.

Mercader, R.J. and J.M. Scriber. 2005. Phenotypic plasticity of host selection in adult tiger swallowtails; Papilio glaucus (L.). In T.N. Ananthakrishnan and D. Whitman (eds.) Insects and phenotypic plasticity. pp. 25-57. Science Publishers, Enfield.