Date of Award
Environmental and Forest Biology
Stephen A. Teale
its discovery in 1997, Philornis downsi has been shown to significantly reduce fledgling success in many bird species within the Galapagos Islands, including endemic and critically endangered species of Darwin’s finches. Despite the level of impact on such highly celebrated birds, there are currently no practical methods of controlling or monitoring P. downsi populations. This study was designed to explore the potential of chemical ecology to remedy these needs. During the month of February 2012 on the Galapagos island of Santa Cruz, we measured the attractiveness of two prospective P. downsi olfactory cues using different designs of baited traps. We evaluated three trap designs for effectiveness. The results indicated cylindrical sticky traps are less effective than McPhail traps in catching P. downsi and horizontal flat sticky traps are not effective at all. While simultaneously testing trap designs, the attractiveness of nest-related odors and fly-produced pheromones were evaluated using lures of dichloromethane extracted host nest headspace volatiles and male/female deceased flies, respectively. Traps baited with nest odors were not attractive in comparison to positive or negative controls (n=7). The testing of pheromonal sources of P. downsi attraction showed that neither male baited traps, female baited traps, nor unbaited traps were able to catch any specimens (n=5). While the ultimate goal of this study, to support the potential for an efficient olfactory-based method of monitoring and controlling P. downsi, was not met, experimental techniques and design details were refined for future investigation of P. downsi chemical ecology.
Doherty, Kristin M., "Chemical attractants of Philornis downsi [Diptera: Muscidae], an invasive parasite of birds in the Galapagos Islands" (2012). Honors Theses. 55.