title: Cytogenetic and symbiont analysis of five members of the B. dorsalis complex (Diptera, Tephritidae): no evidence of chromosomal or symbiont-based speciation events.
abstract: The Bactrocera dorsalis species complex, currently comprising about 90 entities has received much attention. During the last decades, considerable effort has been devoted to delimiting the species of the complex. This information is of great importance for agriculture and world trade, since the complex harbours several pest species of major economic importance and other species that could evolve into global threats. Speciation in Diptera is usually accompanied by chromosomal rearrangements, particularly inversions that are assumed to reduce/eliminate gene flow. Other candidates currently receiving much attention regarding their possible involvement in speciation are reproductive symbionts, such as Wolbachia, Spiroplasma, Arsenophonus, Rickettsia and Cardinium. Such symbionts tend to spread quickly through natural populations and can cause a variety of phenotypes that promote pre-mating and/or post-mating isolation and, in addition, can affect the biology, physiology, ecology and evolution of their insect hosts in various ways. Considering all these aspects, we present: (a) a summary of the recently gained knowledge on the cytogenetics of five members of the Bactrocera dorsalis complex, namely Bactrocera dorsalis s.s., Bactrocera invadens, Bactrocera philippinensis, Bactrocera papayae and Bactrocera carambolae, supplemented by additional data from a Bactrocera dorsalis s.s. colony from China, as well as by a cytogenetic comparison between the dorsalis complex and the genetically close species, Bactrocera tryoni, and, (b) a reproductive symbiont screening of 18 different colonized populations of these five taxa. Our analysis did not reveal any chromosomal rearrangements that could differentiate among them. Moreover, screening for reproductive symbionts was negative for all colonies derived from different geographic origins and/or hosts. There are many different factors that can lead to speciation, and our data do not support chromosomal and/or symbiotic-based speciation phenomena in the taxa under study.
authors.affiliation: Department of Biology, University of Patras, Patras, Greece; Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, Seibersdorf, Vienna, Austria; Department of Environmental and Natural Resources Management, University of Patras, Agrinio, Greece.
authors.forename: Antonios A
authors.initials: AA
authors.lastname: Augustinos
authors.affiliation: Department of Genetics, Development and Molecular Biology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.forename: Elena
authors.initials: E
authors.lastname: Drosopoulou
authors.affiliation: Department of Biology, University of Patras, Patras, Greece.
authors.forename: Aggeliki
authors.initials: A
authors.lastname: Gariou-Papalexiou
authors.affiliation: Department of Environmental and Natural Resources Management, University of Patras, Agrinio, Greece.
authors.forename: Elias D
authors.initials: ED
authors.lastname: Asimakis
authors.affiliation: Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, Seibersdorf, Vienna, Austria.
authors.forename: Carlos
authors.initials: C
authors.lastname: Cáceres
authors.affiliation: Department of Environmental and Natural Resources Management, University of Patras, Agrinio, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Tsiamis
authors.affiliation: Insect Pest Control Laboratory, Joint FAO/IAEA Programme of Nuclear Techniques in Food and Agriculture, Seibersdorf, Vienna, Austria.
authors.forename: Kostas
authors.initials: K
authors.lastname: Bourtzis
authors.affiliation: Department of Genetics, Development and Molecular Biology, School of Biology, Faculty of Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
authors.lastname: Penelope Mavragani-Tsipidou
authors.affiliation: Department of Biology, University of Patras, Patras, Greece.
authors.forename: Antigone
authors.initials: A
authors.lastname: Zacharopoulou
keywords: Tephritidae; Wolbachia; inversions; polytene chromosomes