Table 2.

Baseline and progress on the Bactrocera dorsalis complex.

Method	Knowledge at CRP start and gaps identified	Progress in addressing gaps identified	Output References
DNA Analysis	There is no adequate and consistent sample coverage for the five target species. Nuclear ribosomal ITS1+2 diagnostic for separating Bactrocera carambolae from remaining four species. Mitochondrial DNA markers show no clear distinction between currently defined species. Microsatellite sequences available as well as nuclear coding gene data for 16 loci. Lack of discriminatory characters means that either they are yet to be discovered, or such characters do not exist and the species are the same.	Significantly improved sample coverage, including from China, Indian subcontinent, Myanmar, Indo/Malay Archipelago, and African populations. Additional diagnostic genetic markers (mitochondrial, ribosomal and nuclear genes) developed, but they do not discriminate between four of the five species; Bactrocera carambolae forms a monophyletic group according to COI and ITS1. A full multigene phylogenetic analysis published. Microsatellites indicate origin of Bactrocera dorsalis is China. Y specific primers have been developed and differences of the amplified sequences have been found between Bactrocera dorsalis and Bactrocera carambolae, but not for Bactrocera dorsalis, Bactrocera papayae, Bactrocera philippinensis and Bactrocera invadens. Combined genetic results cannot consistently separate Bactrocera dorsalis, Bactrocera papayae, Bactrocera philippinensis and Bactrocera invadens. Unique markers have been identified for Bactrocera carambolae.	Aketarawong et al. 2014a, 2014b, 2015 this issue, Boykin et al. 2014, Leblanc et al. 2015 this issue
Cytology	Studies on mitotic karyotypes identified several forms within the Bactrocera dorsalis complex, but did not definitively distinguish between putative species. Further polytene maps are needed to allow distinguishing between putative species. Polytene mapping for these species could be linked with genomic data.	Cytological evidence, neither on mitotic nor on polytene chromosomes can discriminate between the five target taxa, therefore these taxa can be regarded as homosequential. Hybrid analysis also shows no chromosomal structural differences; only minor asynapses were observed in a few hybrids between Bactrocera dorsalis and Bactrocera carambolae. In situ hybridization of the six unique sequences shows no evidence for the presence of chromosomal rearrangements. However, analysis of mitotic and polytene chromosomes from both Bactrocera kandiensis and Bactrocera tryoni clearly differentiates these taxa from Bactrocera dorsalis s.s.	Zacharopoulou et al. 2011a, Zacharopoulou and Franz 2013, Augustinos et al. 2015 this issue
Genomics	Unpublished Hawaiian Bactrocera dorsalis s.s. genome. Transcriptomics under way for Bactrocera dorsalis s.s., Bactrocera philippinensis and Bactrocera carambolae, potential of some markers for these species.	Public web portal for accessing the current scaffold and contig structure of the Hawaiian Bactrocera dorsalis s.s. genome. The genome for Bactrocera tryoni and draft genomes for Bactrocera neohumeralis and Bactrocera jarvisi have been published as reference genomes. Comparative transcriptome data for Bactrocera dorsalis s.s., Bactrocera papayae, Bactrocera philippinensis, Bactrocera carambolae and Bactrocera invadens have been analysed for ‘species’ specific SNPs. No specific SNPs could be identified.	Gilchrist et al. 2014, Armstrong et al. (unpubl.)
Morphology	No consensus on species limits of the major Bactrocera dorsalis complex pest species. Explicit intra-specific population-level variation in both external and internal morphological characters. Therefore for some species unable to provide definitive identification of specimens. Egg and immature morphology not investigated for Bactrocera dorsalis complex species.	Bactrocera invadens vs Bactrocera dorsalis s.s. colour morphs described and the range of morphological variation assessed from across their geographic ranges. Crosses between colour morphs (pale brown and black scutum) of Bactrocera dorsalis from Pakistan confirm that scutum colour morph is a simple qualitative genetic trait. Morphological pattern variation in Bactrocera dorsalis s.s has been assessed for flies fed varying quantities of food (standard lab diet). No clear correlation was observed. Egg and immature material has been gathered and is being included as part of a major project describing the immature stages of tephritids.	Leblanc et al. 2013, Leblanc et al. 2015 this issue, Schutze et al. 2015a
Morphometrics	Large number of morphometric studies for Bactrocera dorsalis complex species; often impossible to separate between and within population variation in morphometric traits. Insufficient understanding of relative environmental/genetic influences on morphometric phenotype. Morphometric approaches have rarely been linked adequately with other morphological or genetic approaches.	Geometric morphometric wing shape data are consistent with Bactrocera dorsalis s.s., Bactrocera invadens, Bactrocera papayae and Bactrocera philippinensis representing the same species which displays strong isolation-by-distance patterns within SE Asia. All ‘outgroup’ species resolve strongly from the Bactrocera dorsalis complex species. Aedeagi from a latitudinal gradient from northern Thailand to Peninsular Malaysia for Bactrocera dorsalis s.s. and Bactrocera papayae show a significant and continuous latitudinal cline from north to south, with northern Thailand flies the shortest and Malaysian flies possessing the longest aedeagi. Morphometrics of genitalia, head width and wings have been undertaken for Bactrocera dorsalis s.s. reared under different larval densities.	Schutze et al. 2012a, Schutze et al. 2012b, Krosch et al. 2013, Schutze et al. 2015a
Sexual Behaviour	Knowledge of some mating compatibility for individual species crosses from isolated studies. Lack of comparative mating compatibility studies across populations/species from across their geographic range acquired under equivalent semi-natural conditions.	Comparative field cage studies demonstrating complete pre- and post-zygotic compatibility among Bactrocera dorsalis s.s., Bactrocera invadens, Bactrocera papayae and Bactrocera philippinensis; hybrid offspring obtained between crosses are also viable. Bactrocera carambolae shows partial pre-and post-zygotic incompatibility with Bactrocera dorsalis s.l.. Following methyl-eugenol (ME) feeding by males Bactrocera dorsalis and Bactrocera carambolae, relatively sexual incompatibility remained in cross-mating field cage studies. No compatibility under same conditions with outgroups.	Chinvinijkul et al. 2015 this issue; Schutze et al. 2015c, this issue
Sensitivity to methyl-eugenol (ME)	Male responsiveness to ME varied between Bactrocera dorsalis, Bactrocera papayae and Bactrocera carambolae. Initial feeding on high-concentration ME reduced response to subsequent exposure in Bactrocera dorsalis s.s. The male mating advantage seen following ME-feeding begins later for Bactrocera carambolae relative to Bactrocera dorsalis. Lack of specific knowledge of the ME response of Bactrocera philippinensis and Bactrocera invadens. Species sensitivity to ME across the four species has not been compared.	Probit analysis on the males’ sensitivity to ME showed no significant differences in the ED50 between Bactrocera dorsalis, Bactrocera papayae, Bactrocera philippinensis and Bactrocera invadens. Electrophoretic analyses of the male antennal protein extracts for Bactrocera dorsalis, Bactrocera papayae, Bactrocera philippinensis and Bactrocera invadens also showed no differences in the protein electropherogrammes. This also included that of males exposed to ME.	Hee et al. 2015a this issue
Pheromone Components	Phermononal components following ME consumption identical in Bactrocera dorsalis s.s. and Bactrocera papayae. Endogenous pheromone components different between Bactrocera carambolae and both Bactrocera dorsalis and Bactrocera papayae. Pheromone components of Bactrocera philippinensis and Bactrocera invadens so far not been characterised. ME metabolites (i.e. DMP and E-CF) presence in male rectal gland derived from ME feeding can be used to discriminate against Bactrocera carambolae (which produces only E-CF).	Pheromone components post-ME feeding for Bactrocera invadens and Bactrocera philippinensis males identical to those recorded for Bactrocera dorsalis and Bactrocera papayae, but different to those of Bactrocera carambolae. Pheromone components in male rectal glands and volatile emissions virtually identical among Bactrocera dorsalis, Bactrocera papayae, Bactrocera philippinensis and Bactrocera invadens, but distinctive as compared to Bactrocera carambolae. Ratios of pheromonal components (DMP: E-CF) quantified from male rectal gland (in storage) and volatile emission following ME consumption were not significantly different between Bactrocera dorsalis, Bactrocera papayae, Bactrocera philippinensis and Bactrocera invadens. Endogenously produced pheromone constituents confirmed as unique marker for Bactrocera carambolae (i.e. 6-oxo-1-nonanol) to enable species separation from Bactrocera dorsalis s.l.	Hee et al. 2015a this issue, Tan et al. 2011, Tan et al. 2013
Cuticular hydrocarbons	No cuticular hydrocarbons of the Bactrocera dorsalis complex so far studied.	The identification and quantification of cuticular hydrocarbons of males and females of Bactrocera philippinensis, Bactrocera papayae, Bactrocera dorsalis, Bactrocera invadens and Bactrocera carambolae was performed on the GC×GC/TOFMS. Quantitative as well as qualitative CHC profile differences were found between sexes. Female profiles show high amount of short-chained hydrocarbons, not male profiles.	Kalinova et al. (unpubl.)
Distribution	Collection locality considered ‘species character-state’ in many operational keys. For example, Bactrocera dorsalis within Thailand is restricted to central/northern Thailand and Bactrocera papayae to southern Thailand, but zone of transition between Bactrocera dorsalis s.s. and Bactrocera papayae on the Thai/Malay Peninsula not confirmed. Endemic range of Bactrocera invadens is not known.	Two independent studies show there is no zone of transition between Bactrocera dorsalis s.s. and the former Bactrocera papayae on the Thai/Malay Peninsula based on population genetic data (e.g. Fst values and demonstrated gene flow) and morphological data, supporting a continuum rather than different species. Morphological and wing shape analysis suggests that the native range of invasive African Bactrocera dorsalis (formerly Bactrocera invadens) need not have been restricted to Sri Lanka but may have been more widely distributed across the Indian subcontinent. Bactrocera dorsalis is now recognised as a naturally wide-spread and highly invasive species which occurs across sub-Saharan Africa, across the Indian sub-continent to Asia and into the South Pacific.	Krosch et al. 2013, Aketarawong et al. 2014b, Schutze et al. 2015a
Host Ranges	Well documented for most pest populations being tested, but not yet fully for Bactrocera philippinensis and Bactrocera invadens.	A single host list is being consolidated, which covers Bactrocera dorsalis and the former Bactrocera papayae, Bactrocera invadens and Bactrocera philippinensis.	Luc Leblanc et al. (unpubl.)