Shaw, Joey; Chapman, Elise
University of Tennessee at Chattanooga
Place of Publication
This study aimed to better understand how insects interacted with species of Echinacea in Tennessee and specifically their preference to floral color. Based on previous studies I expected the main visitors to be composed of various bees, beetles and butterflies. Based on previous studies, I hypothesized that most bees (especially social bees) would most likely pollinate the purple/violet morphs of the flower versus the white morph. I also expected the bees would have the most visits to the coneflowers versus any other taxonomic group. I believe bees to be the majority of pollinators based upon the results of Stucky, Gadd, & Arellano (2012) and other pollination studies of Asteraceae species (Figueroa-Castro et al., 2016). I hypothesized there would be fewer generalist pollinators (such as thrips, Diptera, and some Hymenoptera) compared to bees. I also hypothesized that the generalist would be more likely to visit white morphed flowers. The site of my study was in Red Bank, Tennessee 5.5 miles north of the center of downtown Chattanooga, Tennessee in a flat level cleared lawn. This area allowed ample room to set up my specimens in clusters (consisting of five plants each) based on their coloration (purple and white). At each monitoring session of one hour the number and species or genus (whichever could be identified) of each potential pollinator was recorded in relation to the floral color of the plant visited. To potentially indicate the effectiveness of pollinators, the duration of pollination and floral constancy was also monitored. It is important to note that the actual effectiveness of a pollinator could not be determined by this study because there was no direct measurement of growth or germination in relation to each individual plant/insect interaction. The ability of pollinators to carry pollen was assessed by their anatomical parts (e.g., hair density) and literature. The results suggested that overall pollinators were evenly distributed in relation to floral color; though some species did show color preferences. Duration of visits was significantly different for all comparisons run and floral constancy was variable as well. Though this study was not able to directly associate pollination events with the likelihood of fertilization, this study allowed us to see what kinds of insects (how frequently and how long) were visiting these purple coneflowers. The results of this study could be used with future research to help management plans for this genus or help attract certain species to your own garden.
This year's thesis project could not have been done alone and without the help of many dedicated individuals. First and foremost, I would like to thank Dr. Chatzimanolis for being my thesis director. Thank you to Dr. Chatzimanolis for the countless hours of helping identify specimens, editing, advising, and guiding this project. I would also like to thank Dr. Chapman for her help with statistical tests and her willingness to walk me through the test one by one and for her feedback on my project with her pollinator expertise. Last but not least I would like to thank Dr. Shaw for his time and feedback on my project and for bringing his expertise on plants and their side of the pollination interaction to the forefront. This could not have been done without any of you; thank you.
B. S.; An honors thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Bachelor of Science.
Echinacea (Plants); Plant-pollinator relationships
Black, Carmen, "An analysis of the pollinators of Echinacea purpurea in relation to their perceived efficiency and color preferences" (2021). Honors Theses.