Cryptic diversity and gene flow among threeAfrican agricultural pests:Ceratitis rosa,Ceratitis fasciventrisandCeratitis anonae(Diptera,Tephritidae)

Abstract

The 'Ceratitis FAR complex' is a species complex of African fruit flies (Diptera, Tephritidae) including the major agricultural pest Ceratitis rosa and the morphologically similar Ceratitis fasciventris and Ceratitis anonae. To resolve their intra- and interspecific genetic relationships and to estimate gene flow within this complex, we surveyed allelic variation at 16 microsatellite loci in 27 African populations of the three morphospecies. Interpopulation genetic distances and individual Bayesian assignments distinguished five genotypic clusters: two involving C. rosa (R1, R2; that may occur in sympatry), two involving C. fasciventris (F1, F2; with parapatric distributions) and one involving C. anonae (A). Intra- and interspecific patterns of genetic differentiation were not hierarchically structured and genetic differentiation between conspecific clusters (F1-F2 and R1-R2) was higher or comparable with differentiation between heterospecific clusters (e.g. F1-A or R2-A). In some cases, gene flow estimates among morphospecies or among heterospecific genotypic clusters were significantly different from zero, showing the lack of reproductive isolation. Genetic differentiation between genotypic clusters was partly supported by morphological differences observed a posteriori in male secondary sexual characters. These results suggest important revisions to current models of ecological niche requirements and invasion risk of the major agricultural pest C. rosa and provide a basis for a taxonomic re-interpretation of the FAR complex.

Description of new Ceratitis species (Diptera: Tephritidae) from Africa, or how morphological and DNA data are complementary in discovering unknown species and matching sexes

“…Within this section, it belongs to the Ceratitis Far complex as defined by Barr & McPheron (2006) and Virgilio et al (2008). a recent study by Virgilio et al (2013) recognized five microsatellite genotypic clusters within the complex, two of which correspond with Ceratitis rosa. Further studies including morphometrics, developmental physiology, cuticular hydrocarbons, pheromones and mating incompatibility (De Meyer et al 2015b and references therein) provided evidence that these two genotypic clusters represent two distinct entities that should be considered separate species.…”

The chromosomes and the mitogenome of Ceratitis fasciventris (Diptera: Tephritidae): two genetic approaches towards the Ceratitis FAR species complex resolution

“…quilicii are distributed in eastern and southern Africa overlapping with each other and partially with C . fasciventris in Kenya and Tanzania 4, 6–8 . There is increasing concern about the possibility that these species could expand outside their native range similarly to the spread of C .…”

“…fasciventris and one for C . anonae 8 , thus complicating further the phylogenetic relationships and species discrimination in the FAR complex.…”

Evidence of weak genetic structure and recent gene flow between Bactrocera dorsalis s.s. and B. papayae, across Southern Thailand and West Malaysia, supporting a single target pest for SIT applications

“…Recently, several microsatellite DNA markers in tephritid fruit flies were developed and amplified across species (e.g., Bactrocera papayae [18], B. musae [19], B. oleae [20], Rhagoletis cerasi [21], Anastrepha obligua [22], Ceratitis capitata [23,24], and C. rosa [25]). Some of them have been subsequently used for elucidating the population genetic structure of the species complex [26,27]. However, microsatellite DNA markers isolated from one species transferred to other species may provide low genetic diversity due to the clone selection procedure (known as ascertainment bias) [28-30].…”