Download or read book The Effects of Carbon Dioxide on Three Species of Milkweed AsclepiIadaceae and Monarch Butterfly Danaus Plexippus Larva Feeding Preference written by Terri Jenee Matiella and published by . This book was released on 2009 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of Carbon Dioxide on Milkweed Asclepiadaceae and Monarch Butterfly Danaus Plexippus Larva written by Terri Jeneé Matiella and published by . This book was released on 2012 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Common Milkweed Asclepias Syriaca Quality on Monarch Butterfly Danaus Plexippus Oviposition Preference and Larval Performance written by Sydney Gilmour and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Species are experiencing shifts in their phenology (i.e., seasonal timing of recurring biological events) due to climate change, leading to disruptions in the relative timing of interacting species. These shifts can be detrimental to the fitness of the consumer (e.g., herbivore) in the interaction. In its larval form, the monarch butterfly (Danaus plexippus) is a specialist herbivore that feeds on milkweed plants (Asclepias spp.). Given that plants generally experience seasonal declines in quality, it is hypothesized that if climate change disrupts the timing of the larval stage relative to the availability of younger milkweed plants, monarch performance will be negatively affected. In this thesis, I explore the potential for negative consequences for the eastern monarch population due to potential shifts in the timing of their interaction with milkweed-due to phenological shifts in either species. I used field surveys around Ottawa, ON to determine monarch oviposition preference on common milkweed (Asclepias syriaca) plants and the seasonal availability of their preferred plants. To determine the potential consequences for monarch fitness where females oviposit on non-preferred plants, I conducted a field experiment to assess the effect of milkweed size on monarch larval performance. Based on field surveys, females preferentially oviposited on smaller milkweed plants in earlier developmental stages with low levels of discolouration. Plants in early developmental stages were consistently available in large proportion over the summer season. These results suggest that even if the relative timing of the monarch-milkweed interaction in the eastern population is shifted due to climate change, there will likely be suitable milkweed plants available for oviposition throughout the breeding season, which could act as a buffer to disruptions in the relative timing of the interaction. I found that bigger plants exuded more latex and had thicker leaves than smaller plants. However, larval performance was unaffected by these plant quality differences. While it is unclear how the relative timing of the monarch-milkweed interaction will change in the future, my results suggest that shifts in the relative timing of their interaction within the breeding season are unlikely to have negative consequences for larval performance in eastern Ontario. Future studies should determine how the relative timing of the interaction will change in the region and explore how climate change will affect the quality of milkweed plants.

Download or read book Are You what You Eat Selective Sequestration of Toxic Milkweed Cardenolides in the Monarch Butterfly written by Jacob Brammer and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Monarch butterfly, Danaus plexippus, is projected to face substantial quasi-extinction risk over the next 20 years after decades of population decline (Semmens et al., 2016). The butterfly shares an exciting and oft-studied chemical relationship with its larval food source, milkweed. Monarchs have the ability not only to tolerate the plant’s toxic cardenolide defenses, but also to sequester them into their own tissue for defense against predators and parasites. Recent work demonstrating a strong correlation between the cardenolides of the milkweed host and the eventual parasite load of the metamorphosed adult motivated us to further investigate the passage of defenses from plant to herbivore (De Roode et al., 2016). Here we perform a feeding trial with seven unique genets of Common milkweed (Asclepias syriaca) and collect samples of Monarch larvae, pupae, adults and frass. We compare these samples’ cardenolide chemistry to that of their host plants using high-performance liquid chromatography. We find that cardenolide concentration varies significantly between D. plexippus and A. syriaca but not between the individual tissue types mentioned above. Our seven milkweed genets were obtained either from sites in North Carolina or Virginia and this geographic variation did not affect variation in cardenolide concentration. Our results suggest that cardenolide concentration varies over time (throughout development) in insect tissue. We show that some cardenolides identified are substantially more concentrated than others and that some appear only in milkweed or Monarch tissue. We find the relative concentrations of several most prominent cardenolides to vary significantly between plant and insect samples. We show that cardenolide profiles in Monarchs vary significantly from those in milkweed and vary significantly over time. We demonstrate that insects exercise substantial discrimination in their cardenolide sequestration and we show that this sequestered profile is stable throughout their development. The observation of many insect-unique cardenolides suggests some conversion of plant-derived defenses before sequestration. Replication and a larger dataset are needed to draw finer conclusions about differences in cardenolide content between milkweed, Monarchs, and their respective tissues.