Insect Molecular Biology (2003) 12(6), 605 – 611 © 2003 The Royal Entomological Society 605 Blackwell Publishing Ltd. The mitochondrial genome of the olive fly Bactrocera oleae : two haplotypes from distant geographical locations F. Nardi, A. Carapelli, R. Dallai and F. Frati Department of Evolutionary Biology, University of Siena, Siena, Italy Abstract The complete sequence of the olive fly ( Bactrocera oleae) mitochondrial genome has been determined. Two independent haplotypes, from flies of distant geo- graphical origin (Italy and Portugal) were completely sequenced. The molecule is 15 815 bp long, and shows the gene content and organization typical of insects, namely thirteen protein coding genes (PCGs) encod- ing proteins involved in oxidative phosphorylation, two rRNAs, twenty-two tRNAs and a long (949 bp) non- coding region. The genomes of the two fly specimens share the same arrangement, differing by a mere thirty- one point mutations. The differences are mostly transi- tions (26) and synonymous substitutions in PCGs (21). The two new sequences are compared with others already present in the database. Keywords: Bactrocera oleae , olive fly, mitochondrial genome, Tephritidae. Introduction Bactrocera oleae (Gmel) is a member of the family Tephritidae, the ‘true fruit flies’, and a species of considerable economic importance. Adult females ovideposit in ripening fruits of Olea sp., and larvae feed upon the pulp, resulting in a sig- nificant quantitative and qualitative loss in the production of table olives and olive oil. In the Mediterranean basin, olive groves cover about ten million hectares, producing a total of 1.6 million tonnes of olive oil and 750 000 tonnes of table olives. Losses resulting from B. oleae can be quantified as 15% of production, roughly $US800 million / year (Montiel- Bueno & Jones, 2002), not to mention the negative effects on the organolectic properties of the oil. Historically restricted to the Mediterranean basin, and possibly to East Africa and the Near East, B. oleae is expanding its range to virtually every country where olive trees are grown for commercial purposes, including the USA (California and Arizona), and possibly Central and South America (El Salvador, Argen- tina, Chile, Peru and Uruguay) and Central Asia (China) (Augustinos et al ., 2002). The possibility that B. oleae could expand further (e.g. in Australia), or become established in countries where it has been detected in low numbers, has created the most serious concerns, and may lead to regulation of international trades and establishment of quarantine procedures. Very limited data are available to date on B. oleae popu- lation structure and geographical variability, except for two studies that have focused on very specific aspects (Tsakas & Zouros, 1980; Ochando & Reyes, 2000), and the prom- ising, but still preliminary, microsatellite study of Augustinos et al . (2002). However, it is becoming increasingly evident that detailed knowledge of these aspects is required for a comprehensive control strategy to be set up for a given pest, especially when invasive species are concerned (Villablanca et al ., 1998; McPheron, 2000; Roderick, 2003). Possible fields of application are: the establishment of ad hoc regu- lation and quarantine procedures to limit the introduction into new areas, the assessment of the appropriate geographi- cal scale for an area-wide management strategy (Lindquist, 2000), the search for natural enemies based on the identi- fication of the area of origin of the species, and the assess- ment of the actual levels of gene flow and fertility, key to any potential control strategy based on SIT (sterile insect tech- nique) or GeSIT (genetic sterile insect technique). The mitochondrial genome has become established as one of the most useful markers for studies of historical biogeography (Avise, 2000). This is due to its simple modes of inheritance (maternal, nonrecombining), the relatively high mutation rate, and the availability of comparative data and conserved PCR primers that can amplify a number of fragments in most hexapod taxa (Simon et al ., 1994). In this paper we report the complete mitochondrial genome sequence of two specimens of B. oleae from Montecucco (Italy) and Paradela (Portugal). The complete sequence of the mitochondrial genome has been determined to date for over twenty hexapods, in- cluding many species of economic or medical importance, and one fruitfly pest, Ceratitis capitata (Spanos et al . 2000), Received 10 March 2003; accepted after revision 28 July 2003. Correspond- ence: Dr Francesco Nardi, Department of Evolutionary Biology, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy. Tel.: +39 0577234420; fax: +39 0577234476; e-mail: nardifra@unisi.it