Papilio glaucus canadensis

Larvae of the butterfly Papilio glaucus glaucus feed mainly on members of the Magnoliaceae, but rarely survive past the first instar when fed plant material of the genus Populus (Salicaceae). In contrast, larvae of Papilio glaucus canadensis perform well on aspen and other Populus species, but die when fed members of the Magnoliaceae (Lin-droth et al., 1988). The major compounds responsible for the lack of acceptability of Populus species to larvae of Papilio... 

Fig. 7.16 The first-instar survival and penultimate-instar growth performance on paper birch, Betula papyrifera, of different populations of Papilio glaucus canadensis and P. g. glaucus as a function of geographic distance from the plant range (RGR = relative growth rate, ECI = overall efficiency of processing plant biomass Scriber, unpublished data).

Scriber, J. M., Lintereur, G. L. and Evans, M. H. (1982) Foodplant utilization and anew oviposition record for Papilio glaucus canadensis R J (Papilionidae Lepidoptera) in northern Wisconsin and Michigan. Great Lakes Ent., 15, 39-46. 

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