title: Prevalence of Candidatus Erwinia dacicola in wild and laboratory olive fruit fly populations and across developmental stages.
abstract: The microbiome of the olive fruit fly, Bactrocera oleae (Gmelin), a worldwide pest of olives (Olea europaea L.), has been examined for >100 yr as part of efforts to identify bacteria that are plant pathogens vectored by the fly or are beneficial endosymbionts essential for the fly's  survival and thus targets for possible biological control. Because tephritid fruit flies feed on free-living bacteria in their environment, distinguishing between the transient, acquired bacteria of their diet and persistent, resident bacteria that are vertically transmitted endosymbionts  is difficult. Several culture-dependent and -independent studies have identified a diversity of species in the olive fruit fly microbiome, but they have not distinguished the roles of the microbes. Candidatus Erwinia dacicola, has been proposed to be a coevolved endosymbiont of the olive fruit  fly; however, this was based on limited samples from two Italian populations. Our study shows that C. Erwinia dacicola was present in all New and Old World populations and in the majority of individuals of all life stages sampled in 2 yr. Olive fruit flies reared on olives in the laboratory  had frequencies of C. Erwinia dacicola similar to that of wild populations; however, flies reared on artificial diets containing antibiotics in the laboratory rarely had the endosymbiont. The relative abundance of C. Erwinia dacicola varied across development stages, being most  abundant in ovipositing females and larvae. This uniform presence of C. Erwini dacicola suggests that it is a persistent, resident endosymbiont of the olive fruit fly.
authors.affiliation: Department of Biological Sciences, Towson University, [corrected] Baltimore, MD, USA. anneestes@gmail.com
authors.forename: Anne M
authors.initials: AM
authors.lastname: Estes
authors.forename: David J
authors.initials: DJ
authors.lastname: Hearn
authors.forename: Hannah J
authors.initials: HJ
authors.lastname: Burrack
authors.forename: Polychronis
authors.initials: P
authors.lastname: Rempoulakis
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Pierson
mesh_terms: D000818:Animals; D005260:Female; D016998:Helicobacter / Q000302:isolation & purification* / Q000502:physiology; D007558:Italy; D008018:Life Cycle Stages; D008297:Male; D031658:Olea; D011156:Population Density; D012726:Sexual Behavior, Animal; D012741:Sexual Maturation; D013559:Symbiosis; D033621:Tephritidae / Q000254:growth & development / Q000382:microbiology / Q000502:physiology*