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Invasive plant species can have significant ecological and economic impacts. Although numerous hypotheses highlight the importance of the chemical defenses of invasive plant species, the chemical ecology of many invasive plants has not yet been investigated. In this study, we provide the first quantitative investigation of variation in iridoid glycoside(More)
The growth and survival of the Catalpa sphinx, Ceratomia catalpae (Sphingidae), were measured on five different species of Catalpa: C. bignonioides, C. bungeii, C. fargeseii, C. ovata, and C. speciosa. Larval growth varied significantly among these host plant species; however, survival did not differ. Quantification of the iridoid glycoside content of(More)
Selective pressures from host plant chemistry and natural enemies may contribute independently to driving insect herbivores towards narrow diet breadths. We used the specialist caterpillar, Junonia coenia (Nymphalidae), which sequesters defensive compounds, iridoid glycosides, from its host plants to assess the effects of plant chemistry and sequestration(More)
The buckeye butterfly,Junonia coenia (Lepidoptera: Nymphalidae), specializes on plants that contain iridoid glycosides. To determine the fate of these compounds in larvae, pupae, and adults of this species, we reared larvae on artificial diets with and without iridoid glycosides, and on leaves of a host plant,Plantago lanceolata (Plantaginaceae).(More)
Numerous empirical studies have examined ontogenetic trajectories in plant defenses but only a few have explored the potential mechanisms underlying those patterns. Furthermore, most documented ontogenetic trajectories in plant defenses have generally concentrated on aboveground tissues; thus, our knowledge regarding whole plant trends in plant defenses(More)
We examined whether larval and adult behavior, physiology, and chemical defense were altered as a result of host range expansion by the Baltimore checkerspot (Euphydryas phaeton, Nymphalidae) from the native host plant, turtlehead (Cheloneglabra, Scrophulariaceae), to the introduced weed, plantain (Plantago lanceolata, Plantaginaceae). We found that newly(More)
We examined how predation by vespid wasps,Polistes dominulus andP. fuscatus, affected the behavior, growth rate and survivorship of aggregated caterpillars ofHemileuca lucina (Saturniidae). Although these larvae can exhibit a variety of defense and escape behaviors, in general larvae reacted to wasp attacks by clinging to the hostplant. Neighboring larvae(More)
Interspecific hybridization among non-native plant species can generate genotypes that are more reproductively successful in the introduced habitat than either parent. One important mechanism that may serve as a stimulus for the evolution of invasiveness in hybrids is increased variation in secondary metabolite chemistry, but still very little is known(More)
Plant secondary chemistry can vary among plant tissues, individuals, and populations, and this variation has population-level consequences for upper trophic levels. In this study, we examined the multi-trophic consequences of variation in iridoid glycosides, which are a component of plant defense against generalist herbivores and also contribute to the(More)