Resolving cryptic species complexes of major tephritid pests

Abstract

An (CRP)FAO/IAEA Co-ordinated Research Project on “Resolution of Cryptic Species Complexes of Tephritid Pests to Overcome Constraints to SIT Application and International Trade” was conducted from 2010 to 2015. As captured in the CRP title, the objective was to undertake targeted research into the systematics and diagnostics of taxonomically challenging fruit fly groups of economic importance. The scientific output was the accurate alignment of biological species with taxonomic names; which led to the applied outcome of assisting FAO and IAEA Member States in overcoming technical constraints to the application of the (SIT)Sterile Insect Technique against pest fruit flies and the facilitation of international agricultural trade. Close to 50 researchers from over 20 countries participated in the CRP, using coordinated, multidisciplinary research to address, within an integrative taxonomic framework, cryptic species complexes of major tephritid pests. The following progress was made for the four complexes selected and studied:Anastrepha fraterculus complex – Eight morphotypes and their geographic and ecological distributions in Latin America were defined. The morphotypes can be considered as distinct biological species on the basis of differences in karyotype, sexual incompatibility, post-mating isolation, cuticular hydrocarbon, pheromone, and molecular analyses. Discriminative taxonomic tools using linear and geometric morphometrics of both adult and larval morphology were developed for this complex.Bactrocera dorsalis complex – Based on genetic, cytogenetic, pheromonal, morphometric, and behavioural data, which showed no or only minor variation between the Asian/African pest fruit flies Bactrocera dorsalis, Bactrocera papayae, Bactrocera philippinensis and Bactrocera invadens, the latter three species were synonymized with Bactrocera dorsalis. Of the five target pest taxa studied, only Bactrocera dorsalis and Bactrocera carambolae remain as scientifically valid names. Molecular and pheromone markers are now available to distinguish Bactrocera dorsalis from Bactrocera carambolae.Ceratitis FAR Complex (Ceratitis fasciventris, Ceratitis anonae, Ceratitis rosa) – Morphology, morphometry, genetic, genomic, pheromone, cuticular hydrocarbon, ecology, behaviour, and developmental physiology data provide evidence for the existence of five different entities within this fruit fly complex from the African region. These are currently recognised as Ceratitis anonae, Ceratitis fasciventris (F1 and F2), Ceratitis rosa and a new species related to Ceratitis rosa (R2). The biological limits within Ceratitis fasciventris (i.e. F1 and F2) are not fully resolved. Microsatellites markers and morphological identification tools for the adult males of the five different FAR entities were developed based on male leg structures.Zeugodacus cucurbitae (formerly Bactrocera (Zeugodacus) cucurbitae) – Genetic variability was studied among melon fly populations throughout its geographic range in Africa and the Asia/Pacific region and found to ...

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

“…Moreover, the multidisciplinary approach used in integrative taxonomy revealed the presence of cryptic species (see De Meyer et al 2015a for a recent treatise of this in tephritid fruit flies). In groups of economic significance, such as Tephritidae, a proper identification is not only a prerequisite for any further research, be it fundamental or applied, but can also have serious political and economic consequences in aspects like control programs, quarantine regulations, and trade barriers (Hendrichs et al 2015). taxonomic recognition, preferably through different independent approaches, is a necessity and may facilitate accurate recognition of biological species (Clarke & Schutze 2014).…”

“…a case in particular is the description of C. quilicii sp. nov. this is the result of an integrative taxonomic study on a number of cryptic species complexes of economic significance (Hendrichs et al 2015), including the Ceratitis Far complex (Barr & wiegmann 2009;Virgilio et al 2008).…”

“…nov. has been referred to as "R2", "the cold type" or "highland type" (see De Meyer et al 2015b andHendrichs et al 2015, andreferences therein). the Dna barcodes produced for five specimens of C. quilicii sp.…”

A global checklist of the 932 fruit fly species in the tribe Dacini (Diptera, Tephritidae)

“…The source data is, for a large part, comprised of regional treatments (Drew 1989, Hancock and Drew 2006, White 2006, Drew and Romig 2013), with additions and revisions from more recent studies (Drew et al 2011, Yu et al 2012, Hancock 2015, Hancock and Drew 2015, Hendrichs et al 2015, Schutze et al 2015b, David et al 2016, 2017, Drew and Hancock 2016, Freidberg et al 2017, Han et al 2017). Species included in the list are ordered alphabetically by genus.…”

DNA barcodes for bio-surveillance: regulated and economically important arthropod plant pests

“…Another study which examined 193 tephritid species failed to discriminate six species in the B. dorsalis complex (B. dorsalis, B. occipitalis, B. carambolae, B. papaya, B. invadens, B. philippinensis) (Frey et al 2013;Jiang et al 2014). This discrepancy between taxonomic assignments and barcode results (Hendrichs et al 2015) provoked a reevaluation of their taxonomy, work which suggested that at least some of the taxa involved are conspecific (Khamis et al 2012;Schutze et al 2012). In fact, a subsequent taxonomic revision synonymized B. invadens and B. papaya with B. dorsalis (Schutze et al 2015).…”