Browsing by Subject "butterflies"

Now showing 1 - 3 of 3
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    Behavioral ecology of parasitoid diet breadth and insect defenses
    (2017-07) Stenoien, Carl
    One of the primary challenges animals face is consuming enough nutrients of sufficient quality that they might realize their reproductive potential. Many strategies have evolved, but robust explanations for the causes and consequences of variation in diet breadth remain elusive. I’ve used field and comparative lab studies of a specialist parasitoid wasp (Pteromalus cassotis) with a closely-related generalist (Pteromalus puparum) across several potential butterfly host species to better understand how physiological and behavioral trade-offs might limit parasitoids' host ranges. When paired with eleven host species, both parasitoids preferred those hosts on which they performed best, but I found little support for the idea that physiological trade-offs drive the evolution of specialized foraging strategies. Intriguingly, the generalist was more likely than the specialist to accept unsuitable hosts, while the specialist was more likely than the generalist to reject suitable hosts. I also reared monarch butterflies (Danaus plexippus) to be more or less chemically defended and found that host toxicity influenced the behavior and performance of the specialist. The generalist often killed monarch hosts, but was incapable of developing in them. Finally, I investigated the role of behavior in avoiding natural enemy-induced mortality of insect pupae, which are relatively immobile and are often presumed to be vulnerable to natural enemies. I review many examples to show that pupae likely benefit from a variety of behaviors performed before pupation (by the larva or pre-pupa), behaviors of the pupa itself, and behaviors of conspecific and heterospecific individuals. Taken together, my dissertation provides the first details on the natural history and chemical ecology of interactions between P. cassotis and the monarch butterfly. My findings suggest that, in some cases, behavioral decisions may be more important than physiological trade-offs in shaping animal diet breadth. These findings have implications for organisms in rapidly changing environments and biological control efforts because they demonstrate that specialist foragers may retain the evolutionary potential for host switches, and generalists can cause difficult-to-measure non-target mortality.
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    Butterfly Gardening
    (St. Paul, MN: University of Minnesota Extension Service, 1996) Krischik, Vera
    This book describes the life cycle of butterflies, butterfly behaviors, and the types of plants and habitat that will attract and retain butterflies.
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    Post-Fire Associations Of Butterfly Behavior, Occupancy, And Abundance With Environmental Variables And Nectar Sources In The Sierra Nevada, California
    (2015-12) Pavlik, David
    Fire can alter the quality of habitat for butterflies. Fire also affects environmental attributes associated with the distribution, abundance, and reproduction of butterflies. The effects of fire on butterfly occupancy, and on environmental attributes that are associated with butterfly occupancy, are largely unknown. In 2014 and 2015, we conducted butterfly and vegetation surveys within the Rim Fire boundary in California. We analyzed sugar and sucrose masses, and proportion of sucrose, in 20 nectar sources. We found no evidence that intensity of use was associated with sugar mass, mass of sucrose, or the relative proportion of sucrose. We found that environmental attributes associated with occupancy of some species were also associated with the abundances of those species. Burn severity affected environmental attributes that were associated with butterfly occupancy and abundance. Understanding how fire affects environmental attributes associated with occupancy and abundance can inform use of prescribed fire or management following wildfire.