Meeting Abstract
51.1 Jan. 6 Life in a fly: Exploring a variable endosymbiont environment ESTES, Anne M. *; BRONSTEIN, Judith L.; PIERSON, Elizabeth A.; Univ. of Arizona; Univ. of Arizona; Univ. of Arizona amestes@u.arizona.edu
Our understanding of insect-bacterial symbioses stems from systems in which the endosymbiont experiences low variability in morphological and nutritional host environment. Holometabolous insect hosts that are both morphologically and nutritionally variable are understudied. Bacterial symbionts associated with variable endosymbiont environments may be more metabolically plastic than their endosymbiotic relatives in less variable host environments. We describe the symbiosis between the tephritid olive fly, Bactrocera oleae, and two enteric bacteria, Erwinia dacicola and Pantoea sp. The olive fly host undergoes both complete metamorphosis and a diet shift. As the fly switches from feeding on olives as larvae to nectar-feeding as adults, the bacteria may encounter a different set of nutrients and microhabitats. These bacteria are consistently associated with olive flies from climatically distinct sites across California and one site in Arizona. In the 356 individuals screened, 95% of the females and 90% of the males were infected with both bacteria. No olive fly individuals were found with only E. dacicola. Instead, 6.3% of animals had neither bacteria and 1.7% of animals had Pantoea sp. only. Both bacteria are found in all life stages of the fly. To determine the location of bacteria relative to host cells of the digestive systems, transmission electron microscopy was performed on both larval mycetocytes and adult oesophageal bulbs. Bacteria in the larval mycetocytes are intracellular, whereas the bacterial community is extracellular in the adult oesophageal bulbs. This work establishes that the two symbionts, E. dacicola and Pantoea sp., are consistently associated with naturalized populations of B. oleae in the U.S., and begins to examine changes in these endosymbionts during host development.
