2013. Current Status Knowledge Bactrocera dorsalis Complex ...



CURRENT KNOWLEDGE BACTROCERA DORSALIS COMPLEX (August 2013)BackgroundThe Bactrocera dorsalis species complex was first recognised by Hardy (1969), and greatly expanded by Drew and Hancock (1994). Several other taxa have been placed in the complex outside of these two revisions, of which the only one of current relevance is B. invadens (Drew et al. 2005). While the majority of species within the B. dorsalis complex are easily diagnosed on morphological characters, this is not the case for a small group of cryptic taxa which have been the focus of the current project: B. dorsalis s.s. (Hendel), B. papayae Drew & Hancock, B. philippinensis Drew & Hancock, B. carambolae Drew & Hancock and B. invadens Drew, Tsuruta & White.Quite quickly after their original discriptions, concerns were raised as to the biological validity of B. papayae, B. carambolae and B. philippinensis, most notably by Prof Keng Hong Tan and colleagues (Nishida et al. 1988, Tan & Nishida 1996), but these views were subsequently reviewed and dismissed (Clarke et al. 2005, Drew et al. 2008). Nevertheless, repeated failure to find robust and consistent biological markers for these taxa (with the possible exception of B. carambolae), has meant that the question of whether the taxonomic species correctly align with the biological species has never been fully resolved. This component of the CRP was established to (i) accurately delimit the biological species of this clade; and (ii) having done so develop appropriate diagnostic markers.Current statusVery signficant research has been undertaken, within an integrative taxonomic framework, to biologically delimit the target taxa. The tools used have included: i) morphological examination, including traditional morphology, morphometrics of genitalic characters, and fine-scale wing shape analysis using geometric morphometrics; ii) molecular-based approaches using both phylogenetic and population genetic analyses of nuclear DNA sequence and microsatellite data coupled with mitochondrial DNA sequence analysis and comparative transcriptome analysis; iii) studies of mating and post-zygotic sexual compatibility; iv) analysis of rectal gland (= pheromone) constituents; and v) comparative polytene chromosone analysis. Not all work has yet been published, but much has (Tan et al. 2011, Khamis et al. 2012, Schutze et al. 2012a, Schutze et al. 2012b, Boykin et al. 2013, Krosch et al. 2013, Schutze et al. 2013, Tan et al. 2013).With one exception, all data so far presented by CRP participants have failed to find evidence of any species level biological differentiation between B. dorsalis, B. papayae, B. philippinensis and B. invadens. Any genetic and morphological differences which have been found are best explained as intra-specific variation (i.e. population level variation), not inter-specific variation. Data (pheromonal, genetic, behavioural) suggests that B. carambolae is a biologically unique, albeit very closely related species to the other four taxa. It is important to recognise that some critical data sets for B. invadens (e.g. sexual compatability trials) have still to be publically presented, but this ‘missing’ data will be presented in Argentina and is consistent with the other data sets so far presented. The one exception to the general patterns seen in the data sets was a verbal paper presented by Prof Drew at the 2nd RCM (Brisbane, Jan 2012), who analysed thoracic color patterns of B. invadens from Africa and B. dorsalis from China and concluded that the frequency of colors (predominantly red-brown in the African flies and black in the Chinese flies) confirmed these two species as described. Because such color variation might also be interpreted as intra-specific variation in one wide-ranging biological species, more work in this area has been done in the last 18 months and will be presented in Argentina.It is believed that Prof Drew has formally synonymised B. philipinnensis with B. papayae in a soon to be published monograph, but no other taxonomic changes have been made.ConclusionsAll evidence so far suggests that B. dorsalis, B. papayae and B. philippinensis are one biological species, while B. carambolae is a closely related but biologically unique species, albeit natural hybrids between B. carambolae and B. papayae have been detected in the Penisular Malaysia (Tan, 2005, Wee and Tan 2005).B. invadens should also be likely considered a junior synonym of B. dorsalis, but some additional data sets need to be publically presented and peer considered before this can be assumed.The strength of the case for considering the synonymisation of B. papayae, B. philippinensis and B. invadens with B. dorsalis rests not on the strength of any one approach (i.e. mating, pheromone, genetics), but the highly consistent results of all of these independent approaches.ReferencesBoykin, L. M., M. K. Schutze, M. N. Krosch, A. Chomic, T. A. Chapman, A. Englezou, K. F. Armstrong, A. R. Clarke, D. Hailstones, and S. L. Cameron. 2013. Multi-gene phylogenetic analysis of the south-east Asian pest members of the Bactrocera dorsalis species complex (Diptera: Tephritidae) does not support current taxonomy. Journal of Applied Entomology:DOI: 10.1111/jen.12047.Clarke, A. R., K. F. Armstrong, A. E. Carmichael, J. R. Milne, S. Raghu, G. K. Roderick, and D. K. Yeates. 2005. Invasive phytophagous pests arising through a recent tropical evolutionary radiation: The Bactrocera dorsalis complex of fruit flies. Annual Review of Entomology 50:293-319.Drew, R. A. I. and D. L. Hancock. 1994. The Bactrocera dorsalis complex of fruit flies (Diptera: Tephritidae: Dacinae) in Asia. Bulletin of Entomological Research Supplement No. 2:i-iii, 1-68.Drew, R. A. I., S. Raghu, and P. Halcoop. 2008. Bridging the morphological and biological species concepts: studies on the Bactrocera dorsalis (Hendel) complex (Diptera: Tephritidae: Dacinae) in South-east Asia. Biological Journal of the Linnean Society 93:217-226.Drew, R. A. I., K. Tsuruta, and I. M. White. 2005. A new species of pest fruit fly (Diptera: Tephritidae: Dacinae) from Sri Lanka and Africa. African Entomologist 13:149-154.Hardy, D. E. 1969. Taxonomy and distribution of the oriental fruit fly and related species (Tephritidae-Diptera). Proceedings of the Hawaiian Entomological Society 20:395-428.Khamis, F. M., D. K. Masiga, S. A. Mohamed, D. Salifu, M. d. Meyer, and S. Ekesi. 2012. Taxonomic identity of the Invasive fruit fly pest, Bactrocera invadens: Concordance in morphometry and DNA barcoding. PLoS ONE:7(9) e44862. doi:44810.41371/journal.pone.0044862.Krosch, M. N., M. K. Schutze, K. F. Armstrong, Y. Boontop, L. M. Boykin, T. A. Chapman, A. Englezou, S. L. Cameron, and A. R. Clarke. 2013. Piecing together an integrative taxonomic puzzle: microsatellite, wing shape and aedeagus length analysis of Bactrocera dorsalis s.l. (Diptera: Tephritidae) find no evidence of multiple lineages in a proposed contact zone along the Thai/Malay Peninsula. Systematic Entomology 38:2-13.Nishida, R., K.H. Tan, M. Serit, N.H.Lajis, A.M. Sukari, S. Takahashi and H. Fukami. 1988. Accumulation of phenylpropanoids in the rectal glands of male Oriental fruit fly, Dacus dorsalis. Experientia 44:534-536.Schutze, M., A. Jessup, I. Ul-Haq, M. J. B. Vreysen, V. Wornoayporn, M. T. Vera, and A. R. Clarke. 2013. Mating compatibility among four pest members of the Bactrocera dorsalis fruit fly species complex (Diptera: Tephritidae). Journal of Economic Entomology 106:695-707.Schutze, M. K., A. Jessup, and A. R. Clarke. 2012a. Wing shape as a potential discriminator of morphologically similar pest taxa within the Bactrocera dorsalis species complex (Diptera: Tephritidae). Bulletin of Entomological Research 102:103-111.Schutze, M. K., M. N. Krosch, K. F. Armstrong, T. A. Chapman, A. Englezou, A. Chomi?, S. L. Cameron, D. L. Hailstones, and A. R. Clarke. 2012b. Population structure of Bactrocera dorsalis s.s., B. papayae and B. philippinensis (Diptera: Tephritidae) in southeast Asia: evidence for a single species hypothesis using mitochondrial DNA and wing-shape data. BMC Evolutionary Biology 12:130. doi:110.1186/1471-2148-1112-1130.Tan, K. H. 2005. Interbreeding and DNA analysis of Bactrocera dorsalis sibling species. pp 113 – 122. In: Recent Trends on Sterile Insect Technique and Area-Wide Integrated Pest Management - Economic Feasibility, Control Projects, Farmer Organization and Bactrocera dorsalis Complex Control Study. Research Institute for the Subtropics, Okinawa,Japan. Tan, K. H. and R. Nishida. 1996. Sex pheromone and mating competition after methyl eugenol consumption in Bactrocera dorsalis complex. pp. 147-153. In: B. A.McPheron and G.J. Steck (eds.) Fruit Fly Pests – A World Assessment of their Biology and Management. St.Lucie Press, Florida.Tan, K. H., I. Tokushima, H. Ono, and R. Nishida. 2011. Comparison of phenylpropanoid volatiles in male rectal and pheromone gland after methyl eugenol consumptions, and molecular phylogenetic relationship of four global pest fruit fly species: Bactrocera invadens, B. dorsalis, B. correcta and B. zonata. Chemoecology 21:25-33.Tan, K. H., S.L. Wee, H. Ono, and R. Nishida. 2013. Comparison of methyl eugenol metabolites, mitochondrial COI, and rDNA sequences of Bactrocera philippinensis (Diptera: Tephritidae) with those of three other major pest species within the dorsalis complex. Applied Entomology and Zoology 48:275-282. Wee, S. L. and K. H. Tan. 2005. Evidence of natural hybridization between two sympatric sibling species of Bactrocera dorsalis complex based on pheromone analysis. Journal of Chemical Ecology 31:845-858. ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download