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Abstract Background Fruit flies (Diptera: Tephritidae) comprise species of agricultural and economic importance. Five such fruit fly species are known to affect commercial fruit production and export in South Africa: Ceratitis capitata, Ceratitis cosyra, Ceratitis rosa, Ceratitis quilicii, and Bactrocera dorsalis. Management practices for these pests include monitoring, application of pest control products, post-harvest disinfestation measures and inspection of consignments both prior to shipment and at ports of entry. In activities relating to monitoring and inspection, accurate identification of these pests to species level is required. While morphological keys for adult stages of these fruit fly species have been well developed, morphological keys for earlier life stages remain problematic. In instances where closely related species cannot be reliably distinguished morphologically, there is a need for molecular tools to assist in identifying these five fruit fly species during surveillance practices, where sequencing-based approaches would be beneficial. Results Two complete mitochondrial genomes were assembled for each fruit fly species investigated using high throughput sequencing data generated in this study. A single primer set was designed to amplify a region between tRNAile and tRNAmet. The amplicon consists of a partial segment of tRNAile, intergenic region I (tRNAile - tRNAgln), the complete sequence of tRNAgln, intergenic region II (tRNAgln - tRNAmet), and a partial segment of tRNAmet. PCR amplicons were generated for 20 specimens of each species, five of which were colony adult males, five colony larvae, and 10 wild, trap-collected specimens. Upon analysis of the amplicon, intergenic region I was identified as the most informative region, allowing for unambiguous identification of the five fruit fly species. The similarity in intergenic region II was too high between C. rosa and C. quilicii for accurate differentiation of these species. Conclusion The identity of all five fruit flies investigated in this study can be determined through sequence analysis of the mitochondrial intergenic regions. Within the target amplicon, intergenic region I (tRNAile - tRNAgln) shows interspecific variation sufficient for species differentiation based on multiple sequence alignment. The variation in the length of intergenic region I is proposed as a potential tool for accurately identifying these five fruit flies in South Africa.

Background: Fruit flies (Diptera: Tephritidae) comprise species of agricultural and economic importance. Five such fruit fly species are known to affect commercial fruit production and export in South Africa: Ceratitis capitata, Ceratitis cosyra, Ceratitis rosa, Ceratitis quilicii, and Bactrocera dorsalis. Management practices for these pests include monitoring, application of pest control products, post-harvest disinfestation measures and inspection of consignments both prior to shipment and at ports of entry. In activities relating to monitoring and inspection, accurate identification of these pests to species level is required. While morphological keys for adult stages of these fruit fly species have been well developed, morphological keys for earlier life stages remain problematic. In instances where closely related species cannot be reliably distinguished morphologically, there is a need for molecular tools to assist in identifying these five fruit fly species during surveillance practices, where sequencing-based approaches would be beneficial. Results: Two complete mitochondrial genomes were assembled for each fruit fly species investigated using high throughput sequencing data generated in this study. A single primer set was designed to amplify a region between tRNAile and tRNAmet. The amplicon consists of a partial segment of tRNAile, intergenic region I (tRNAile - tRNAgln), the complete sequence of tRNAgln, intergenic region II (tRNAgln - tRNAmet), and a partial segment of tRNAmet. PCR amplicons were generated for 20 specimens of each species, five of which were colony adult males, five colony larvae, and 10 wild, trap-collected specimens. Upon analysis of the amplicon, intergenic region I was identified as the most informative region, allowing for unambiguous identification of the five fruit fly species. The similarity in intergenic region II was too high between C. rosa and C. quilicii for accurate differentiation of these species. Conclusion: The identity of all five fruit flies investigated in this study can be determined through sequence analysis of the mitochondrial intergenic regions. Within the target amplicon, intergenic region I (tRNAile - tRNAgln) shows interspecific variation sufficient for species differentiation based on multiple sequence alignment. The variation in the length of intergenic region I is proposed as a potential tool for accurately identifying these five fruit flies in South Africa. [ABSTRACT FROM AUTHOR]

South Africa is the 13th largest producer and second largest exporter of citrus fruit globally. The false codling moth, Thaumatotibia leucotreta, and the fruit flies, Ceratitis capitata, C. rosa and Bactrocera dorsalis, can potentially infest citrus fruit and therefore pose a phytosanitary risk for export markets. Consequently, a wide range of postharvest phytosanitary treatments for disinfestation of citrus fruit from these pests have been investigated. These include cold treatments, irradiation, fumigation, heat treatments, and combinations of some of these. Due to the potential phytotoxic effects of all these treatments, the use of a systems approach that depends on two or more independent measures for acceptable phytosanitary risk mitigation is a preferable option. To date, the only postharvest disinfestation treatments used commercially for T. leucotreta and fruit flies for South African citrus, are stand-alone cold treatments and partial cold treatments, as a component in a multi-tiered systems approach. Research on development of novel and improvement of existing postharvest measures continues as a high priority. This includes postharvest detection technologies, in addition to treatment technologies. [ABSTRACT FROM AUTHOR]

South Africa is the 13th largest producer and second largest exporter of citrus fruit globally. The false codling moth, Thaumatotibia leucotreta, and the fruit flies, Ceratitis capitata, C. rosa and Bactrocera dorsalis, can potentially infest citrus fruit and therefore pose a phytosanitary risk for export markets. Consequently, a wide range of postharvest phytosanitary treatments for disinfestation of citrus fruit from these pests have been investigated. These include cold treatments, irradiation, fumigation, heat treatments, and combinations of some of these. Due to the potential phytotoxic effects of all these treatments, the use of a systems approach that depends on two or more independent measures for acceptable phytosanitary risk mitigation is a preferable option. To date, the only postharvest disinfestation treatments used commercially for T. leucotreta and fruit flies for South African citrus, are stand-alone cold treatments and partial cold treatments, as a component in a multi-tiered systems approach. Research on development of novel and improvement of existing postharvest measures continues as a high priority. This includes postharvest detection technologies, in addition to treatment technologies.

Abstract Fruit from 12 plant species of the family Myrtaceae Juss. were sampled from 2010 to 2017 in the Mpumalanga and Limpopo provinces of South Africa to obtain information on the host utilization of the economically important fruit fly species (Diptera: Tephritidae) and the false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae). Bactrocera dorsalis (Hendel) was reared from five plant species, and significantly more B. dorsalis /kg fruit were reared from Syzygium samarangense (Blume) Merr. & L.M.Perry (P < 0.0001). Four plant species were not previously recorded as hosts for B. dorsalis in South Africa. Ceratitis capitata (Wiedemann) was reared from six plant species and significantly more were reared from Eugenia uniflora L. (P < 0.0001). Ceratitis cosyra (Walker) was reared from five plant species and only a few samples were positive with relatively low infestation indices. Ceratitis rosa sensu lato Karsch was reared from nine Myrtaceae fruit types. One hundred percent of Acca sellowiana (O.Berg) Burret, Psidium cattleianum Afzel. ex Sabine, and S. samarangense samples were positive for Ceratitis rosa sensu lato Karsch. The mean infestation index for C. rosa s.l. differed significantly between the fruit types, and significantly more were reared from P. cattleianum (P < 0.0001). From 2016, distinction was made between males of C. rosa sensu stricto and Ceratitis quilicii De Meyer, Mwatawala and Virgilio. Males from both species were reared from A. sellowiana , Psidium guajava L. and Syzygium jambos (L.) Alston while only C. rosa s.s. was reared from P. cattleianum, Psidium friedrichsthalianum (O.Berg) Nied. and Syzygium cordatum Hochst. ex Krauss. No fruit flies were reared from Plinia cauliflora (Mart.) Kausel and Syzygium paniculatum Gaertn. Thaumatotibia leucotreta was reared from 11 Myrtaceae fruit types. Acca sellowiana, P. cauliflora , P. cattleianum , P. friedrichsthalianum , S. paniculatum and S. samarangense were not previously recorded as host plants for T. leucotreta. Fruit flies and T. leucotreta were reared from fruit sampled from the tree and from the ground highlighting the importance of sanitation as a method to suppress pest population levels. The presence of economically-important fruit flies and T. leucotreta in invasive plant species highlights the importance of controlling these plants as they can serve as a reservoir when cultivated fruit are not present. Myrtaceae plants commonly found in gardens were also identified as hosts and these plants could serve as a breeding place for fruit flies and T. leucotreta. These pests could move from home gardens to orchards when fruit start to mature. Highlights • Bactrocera dorsalis was reported for the first time in South Africa from four host plants. • New host plants were recorded for Thaumatotibia leucotreta. • Myrtaceae host plants are important for Ceratitis rosa s.l. • Sanitation is important for control of fruit flies and Thaumatotibia leucotreta. [ABSTRACT FROM AUTHOR]

Fruit flies are among the most economically important fruit pests worldwide. The larvae are phytophagous and constitute a major production constraint in the horticultural industry. Various indigenous fruits were sampled from 2010 to 2015 in Limpopo and Mpumalanga Provinces of South Africa to determine the presence of fruit fly species. The Oriental fruity fly, Bactrocera dorsalis (Hendel), Mediterranean fruit fly, Ceratitis capitata (Wiedemann), the Marula fruit fly, Ceratitis cosyra (Walker) and the Natal fruit fly, Ceratitis rosa sensu lato Karsch were reared from the indigenous fruits. B. dorsalis was reared from one marula, Sclerocarya birrea (A.Rich.) Hochst. (Anacardiaceae) sample. All three Ceratitis species were reared from the Mobola plum, Parinari curatellifolia Planch. ex Benth. (Chrysobalanaceae) and Kei-apple, Dovyalis caffra (Hook.f. & Harv.) Sim (Salicaceae). Wild plum, Harpephyllum caffrum Bernh. (Anacardiaceae), African mangosteen, Garcinia livingstonei T.Anderson (Clusiaceae), Cape ash, Ekebergia capensis Sparrm. (Meliaceae), waterberry, Syzygium cordatum Hochst. ex Krauss (Myrtaceae) and stemfruit, Englerophytum magalismontanum (Sond.) T.D.Penn. (Sapotaceae) were hosts to both C. capitata and C. rosa s.l. C. capitata was also reared from num-num, Carissa bispinosa (L.) Desf. ex Brenan (Apocynaceae), simple-spined num-num, Carissa spinarum L. (Apocynaceae), brown ivory, Berchemia discolor (Klotzsch) Hemsl. (Rhamnaceae), wild coffee, Coffea racemosa Lour. (Rubiaceae) and common red milkwood, Mimusops zeyheri Sond. (Sapotaceae). C. cosyra was also found in the fruit of S. birrea and the wild mango, Cordyla africana Lour. (Leguminosae). C. rosa s.l. was also reared from Natal plum, Carissa macrocarpa (Eckl.) A. DC. (Apocynaceae), waterpear, Syzygium guineense (Willd.) DC. (Myrtaceae), Natal dovyalis, Dovyalis longispina (Harv.) Warb. (Salicaceae) and wild apricot, Dovyalis zeyheri (Sond.) Warb. (Salicaceae). No fruit flies were reared from Ficus spp. (Moraceae).Various indigenous hosts could serve as a reservoir for infesting cultivated crops. [ABSTRACT FROM AUTHOR]

The avocado industry is important in South Africa, but access to certain markets is impeded by the presence of phytosanitary pests. One of the ways of securing entry to these markets is to demonstrate that a mitigating treatment will result in there being a negligible chance of accidental importation. In cold treatment comparative studies at 0 °C and 2 °C of immature stages of Ceratitis capitata (Wiedemann), Ceratitis rosa Karsch, and Ceratitis cosyra (Walker) in "Hass" avocado, the third instar of C. cosyra was shown to be the most cold tolerant. This larval life stage was used in a large-scale trial to test treatment efficacy at 2 °C, a temperature known to be the better for fruit quality. There were no survivors from the 49,795 individual fruit fly larvae subjected to the cold treatment at 2 °C for 20 d. It is argued that, although this level of assessment falls short of the Probit 9 level normally required for fruit fly, they are rarely found in avocado fruit and that the level of disinfestation obtained is more than sufficient to achieve quarantine security. [ABSTRACT FROM AUTHOR]

An FAO/IAEA Co-ordinated Research Project (CRP) 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 Sterile Insect Technique (SIT) 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, B. papayae, B. philippinensis and B. invadens, the latter three species were synonymized with B. dorsalis. Of the five target pest taxa studied, only B. dorsalis and B. carambolae remain as scientifically valid names. Molecular and pheromone markers are now available to distinguish B. dorsalis from B. carambolae. Ceratitis FAR Complex (C. fasciventris, C. anonae, C. 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, C. fasciventris (F1 and F2), C. rosa and a new species related to C. rosa (R2). The biological limits within C. 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 be limited. Cross-mating studies indicated no incompatibility or sexual isolation. Host preference and genetic studies showed no evidence for the existence of host races. It was concluded that the melon fly does not represent a cryptic species complex, neither with regard to geographic distribution nor to host range. Nevertheless, the higher taxonomic classification under which this species had been placed, by the time the CRP was started, was found to be paraphyletic; as a result the subgenus Zeugodacus was elevated to genus level. [ABSTRACT FROM AUTHOR]

Comparative analysis of development and survivorship of two geographically divergent populations of the Natal fruit fly Ceratitis rosa Karsch designated as C. rosa R1 and C. rosa R2 from Kenya and South Africa were studied at seven constant temperatures (10, 15, 20, 25, 30, 33, 35 °C). Temperature range for development and survival of both populations was 15-35 °C. The developmental duration was found to significantly decrease with increasing temperature for C. rosa R1 and C. rosa R2 from both countries. Survivorship of all the immature stages of C. rosa R1 and C. rosa R2 from Kenya was highest over the range of 20-30 °C (87-95%) and lowest at 15 and 35 °C (61-76%). Survivorship of larvae of C. rosa R1 and C. rosa R2 from South Africa was lowest at 35 °C (22%) and 33 °C (0.33%), respectively. Results from temperature summation models showed that C. rosa R2 (egg, larva and pupa) from both countries were better adapted to low temperatures than R1, based on lower developmental threshold. Minimum larval temperature threshold for Kenyan populations were 11.27 °C and 6.34 °C (R1 and R2, respectively) compared to 8.99 °C and 7.74 °C (R1 and R2, respectively) for the South African populations. Total degree-day (DD) accumulation for the Kenyan populations were estimated at 302.75 (C. rosa R1) and 413.53 (C. rosa R2) compared to 287.35 (C. rosa R1) and 344.3 (C. rosa R2) for the South African populations. These results demonstrate that C. rosa R1 and C. rosa R2 from both countries were physiologically distinct in their response to different temperature regimes and support the existence of two genetically distinct populations of C. rosa. It also suggests the need for taxonomic revision of C. rosa, however, additional information on morphological characterization of C. rosa R1 and C. rosa R2 is needed. [ABSTRACT FROM AUTHOR]

Previous attempts to resolve the Ceratitis FAR complex (C. fasciventris, C. anonae, C. rosa, Diptera, Tephritidae) showed contrasting results and revealed the occurrence of five microsatellite genotypic clusters (A, F1, F2, R1, R2). In this paper we explore the potential of wing morphometrics for the diagnosis of FAR morphospecies and genotypic clusters. We considered a set of 227 specimens previously morphologically identified and genotyped at 16 microsatellite loci. Seventeen wing landmarks and 6 wing band areas were used for morphometric analyses. Permutational multivariate analysis of variance detected significant differences both across morphospecies and genotypic clusters (for both males and females). Unconstrained and constrained ordinations did not properly resolve groups corresponding to morphospecies or genotypic clusters. However, posterior group membership probabilities (PGMPs) of the Discriminant Analysis of Principal Components (DAPC) allowed the consistent identification of a relevant proportion of specimens (but with performances differing across morphospecies and genotypic clusters). This study suggests that wing morphometrics and PGMPs might represent a possible tool for the diagnosis of species within the FAR complex. Here, we propose a tentative diagnostic method and provide a first reference library of morphometric measures that might be used for the identification of additional and unidentified FAR specimens. [ABSTRACT FROM AUTHOR]

The cuticular hydrocarbons (CHs) and morphology of two Ceratitis rosa Karsch (Diptera: Tephritidae) populations, putatively belonging to two cryptic taxa, were analysed. The chemical profiles were characterised by two-dimensional gas chromatography with mass spectrometric detection. CHs of C. rosa that originated from the lowlands and highlands of Kenya comprised of n-alkanes, monomethylalkanes, dimethylalkanes and unsaturated hydrocarbons in the range of the carbon backbone from C14 to C37. Hydrocarbons containing C29, C31, C33 and C35 carbon atoms predominated in these two populations. 2-Methyltriacontane was the predominant compound in both populations. Quantitative differences in the distribution of hydrocarbons of different chain lengths, mainly the C22, C32, C33 and C34 compounds of these two populations, were observed despite indistinct qualitative differences in these hydrocarbons. Morphological analyses of male legs confirmed that the flies belong to different morphotypes of C. rosa previously labelled as R1 and R2 for lowland and highland populations, respectively. A statistical analysis of the CH compositions of the putative R1 and R2 species showed distinct interspecific identities, with several CHs specific for each of the lowland and highland populations. This study supports a hypothesis that the taxon C. rosa consists of at least two biological species. [ABSTRACT FROM AUTHOR]

The study of sexual behavior and the identification of the signals involved in mate recognition between con-specifics are key components that can shed some light, as part of an integrative taxonomic approach, in delimitating species within species complexes. In the Tephritidae family several species complexes have received particular attention as they include important agricultural pests such as the Ceratitis fasciventris (Bezzi), Ceratitis anonae (Graham) and Ceratitis rosa Karsch (FAR) complex, the Bactrocera dorsalis (Hendel) complex and the Anastrepha fraterculus (Wiedemann) complex. Here the value and usefulness of a methodology that uses walk-in field cages with host trees to assess, under semi-natural conditions, mating compatibility within these complexes is reviewed, and the same methodology to study the role of chemical communication in pre-mating isolation among A. fraterculus populations is used. Results showed that under the same experimental conditions it was possible to distinguish an entire range of different outcomes: from full mating compatibility among some populations to complete assortative mating among others. The effectiveness of the methodology in contributing to defining species limits was shown in two species complexes: A. fraterculus and B. dorsalis, and in the case of the latter the synonymization of several established species was published. We conclude that walk-in field cages constitute a powerful tool to measure mating compatibility, which is also useful to determine the role of chemical signals in species recognition. Overall, this experimental approach provides a good source of information about reproductive boundaries to delimit species. However, it needs to be applied as part of an integrative taxonomic approach that simultaneously assesses cytogenetic, molecular, physiological and morphological traits in order to reach more robust species delimitations. [ABSTRACT FROM AUTHOR]

This paper reviews all information gathered from different disciplines and studies to resolve the species status within the Ceratitis FAR (C. fasciventris, C. anonae, C. rosa) complex, a group of polyphagous fruit fly pest species (Diptera, Tephritidae) from Africa. It includes information on larval and adult morphology, wing morphometrics, cuticular hydrocarbons, pheromones, microsatellites, developmental physiology and geographic distribution. The general consensus is that the FAR complex comprises C. anonae, two species within C. rosa (so-called R1 and R2) and two putatitve species under C. fasciventris. The information regarding the latter is, however, too limited to draw final conclusions on specific status. Evidence for this recognition is discussed with reference to publications providing further details. [ABSTRACT FROM AUTHOR]

BACKGROUND Two Ceratitis spp. coexist on the island of La Réunion, Ceratitis rosa (Karsch) and C. capitata (Wiedemann). The effectiveness of candidate systems based on attractants and traps to control both species was evaluated through comparative studies of trap types, attractants, insecticides and commercial complete systems. RESULTS The Ceratitis spp. most captured in all trials was C. rosa. Captures of C. rosa and C. capitata were not significantly different when Maxitrap® or Tephri-trap® were used. Captures with the Easy-trap® were lower for both species. The BioLure® Med Fly lure showed higher catches of C. rosa than Ferag® CC D TM. The proportion of dead C. rosa did not differ significantly when deltamethrin or dichlorvos was used. There were no significant differences in the capture of C. rosa and C. capitata between commercial systems composed of the lure Ferag® CC D TM, the Maxitrap® and dichlorvos and the BioLure® Unipak, the Tephri-trap® and dichlorvos. The Cera Trap® system performed less effectively. CONCLUSION The most effective traps for the capture of C. rosa and C. capitata were Maxitrap® and Tephri-trap®; the most effective attractants were BioLure® Med Fly for C. rosa and BioLure® Med Fly, BioLure® Unipak and Ferag® CC D TM for C. capitata. However, for both species the most effective commercial combinations of trap and attractant were Maxitrap® with Ferag® CC D TM and Tephri-trap® with BioLure® Unipak, both using dichlorvos. The insecticide deltamethrin showed good efficacy when used inside traps. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: The use of the organophosphate malathion (mercaptothion) in protein bait sprays for fruit fly (Diptera: Tephritidae) control in South African citrus orchards will slowly phase out due to lower tolerances of residues of this insecticide on fruit destined for export markets. As such, a replacement for malathion is being sought. In this study, efficacy of six insecticides: abamectin, alpha-cypermethrin, fipronil, imidacloprid, spinosad and tartar emetic, in combination with HymLure (a protein based attractant), was determined in laboratory assays on female Mediterranean fruit flies, Ceratitis capitata Wiedemann. Three concentrations of HymLure (0.8%, 2% and 10%) were tested with five concentrations of each insecticide. Thereafter the efficacy of the most promising attractant–insecticide combination was determined and compared in the laboratory and in a citrus orchard to standard HymLure–malathion (mixture of 0.8% HymLure and malathion at 875 ppm, diluted in water) and GF-120 (5%, diluted in water) treatments for C. capitata and Ceratitis rosa Karsch (Natal fly). Among the insecticides tested, spinosad was found to induce the highest fly mortality in a shorter time over the whole range of concentrations tested, with mortality reaching above 80% after 24 h when combined with a solution of either 2% HymLure or 10% HymLure. Fipronil, tartar emetic and imidacloprid did not act as fast but were also effective, especially when combined with higher concentrations of HymLure. A mixture of 2% HymLure and spinosad at 48 ppm was found to be effective against both C. capitata and C. rosa in both laboratory and field tests and could therefore be recommended as a replacement for malathion-based bait sprays. [Copyright &y& Elsevier]

Abstract: Acclimation in the thermal tolerance range of insects occurs when they are exposed to novel temperatures in the laboratory. In contrast to the large number of studies that have tested for the ability of insects to acclimate, relatively few have sought to determine the time-course for attainment and reversal of thermal acclimation. In this study the time required for the Mediterranean fruit fly, Ceratitis capitata Wiedemann, and the Natal fruit fly, Ceratitis rosa Karsch, to acclimate to a range of constant temperatures was tested by determining the chill-coma recovery time and heat knock-down time of flies that had been exposed to novel benign temperatures for different durations. The time required for reversal of acclimation for both Ceratitis species was also determined after flies had been returned to the control temperature. Acclimation to 31°C for only one day significantly improved the heat knock-down time of C. capitata, but also led to slower recovery from chill-coma. Heat knock-down time indicated that acclimation was achieved after only one day in C. rosa, but it took three days for C. rosa to exhibit a significant acclimation response to a novel temperature of 33°C when measured using chill-coma recovery time. Reversal of acclimation after return to initial temperature conditions was achieved after only one day in both C. capitata and C. rosa. Adult C. capitata held at 31.5°C initially exhibited improved heat knock-down times but after 9 days the heat knock-down time of these flies had declined to levels not significantly different from that of control flies held at the baseline temperature of 24°C. In both Ceratitis species, heat knock-down time declined with age whereas chill-coma recovery time increased with age, indicating an increased susceptibility to high and low temperatures, respectively. [Copyright &y& Elsevier]

Abstract: The purpose of this paper is to summarize recent research on longevity, aging and adaptation in wild medfly populations and in a close relative of the medfly. The key findings include a new life table identity that relates age structure and the distribution of deaths in stationary populations, seasonal variation in the post-capture longevity of trapped medflies of unknown age, greater longevity of once-wild (wild-caught) adult medflies relative to never-wild (laboratory-emerged) individuals, differences in age specificity of different medfly field capture methods, large variation in the sex-specific longevity of six medfly global biotypes (e.g. Kenya; Brazil; Greece), and the extraordinary longevity of the natal fruit fly — a sister species of the medfly. The discussion contains a listing of discoveries derived from this recent research that appear to be unique to the investigations on medfly aging in the wild. It is suggested that studies of aging in wild populations of Drosophila melanogaster have the potential to exploit this model organism in an entirely new aging research domain and thus complement the already deep literature on aging in this species. [Copyright &y& Elsevier]

Variation in lifespan may be linked to geographic factors. Although latitudinal variation in lifespan has been studied for a number of species, altitude variation has received much less attention, particularly in insects. We measured the lifespan of different populations of the Natal fruit fly, Ceratitis rosa, along an altitudinal cline. For the different populations, we first measured the residual longevity of wild flies by captive cohort approach and compared the F1 generation from the same populations. We showed an increase in lifespan with higher altitude for a part of the data obtained. For the field-collected flies ( F0) the average remaining lifespan increased monotonically with altitude for males but not for females. For the F1 generation, the longevity of both males and females of the highest-altitude population was longer than for the two other lower-altitude populations. This relationship between altitude and lifespan may be explained by the effects of temperature on reproduction. Reproductive schedules in insects are linked to temperature: lower temperature, which is characteristic of high-altitude sites, generally slows down reproduction. Because of a strong trade-off between reproduction and longevity, we therefore observed a longer lifespan for the high-altitude populations. Other hypotheses, such as different predation rates in the different sites, are also discussed. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101, 345–350. [ABSTRACT FROM AUTHOR]

Exotic fruit flies (Ceratitis spp.) are often serious agricultural pests. Here, we used pathway analysis and Monte Carlo simulations to assess the risk of introduction of Ceratitis capitata (Wiedemann), Ceratitis cosyra (Walker), and Ceratitis rosa Karsch, into southern China with fruit consignments and incoming travelers. Historical data, expert opinions, relevant literature, and archives were used to set appropriate parameters in the pathway analysis. Based on the ongoing quarantine/inspection strategies of China, as well as the interception records, we estimated the annual number of each fruit fly species entering Guangdong province undetected with commercially imported fruit, and the associated risk. We also estimated the gross number of pests arriving at Guangdong ports with incoming travelers and the associated risk. Sensitivity analysis also was performed to test the impact of parameter changes and to assess how the risk could be reduced. Results showed that the risk of introduction of the three fruit fly species into southern China with fruit consignments, which are mostly transported by ship, exists but is relatively low. In contrast, the risk of introduction with incoming travelers is high and hence deserves intensive attention. Sensitivity analysis indicated that either ensuring all shipments meet current phytosanitary requirements or increasing the proportion of fruit imports sampled for inspection could substantially reduce the risk associated with commercial imports. Sensitivity analysis also provided justification for banning importation of fresh fruit by international travelers. Thus, inspection and quarantine in conjunction with intensive detection were important mitigation measures to reduce the risk of Ceratitis spp. introduced into China. [ABSTRACT FROM AUTHOR]

There have been relatively few attempts to model the distributions of the fruit flies Ceratitis capitata (Wiedemann), Ceratitis cosyra (Walker), and Ceratitis rosa Karsch in China, but the geographic distributions of these species are of considerable concern in terms of biosecurity. In this study, two different modeling methods (genetic algorithm for rule-set prediction [CARP] and maximum entropy species distribution modeling [Maxent]) were used to predict the potential distributions of these three fly species in China, by using distribution records and a set of environmental predictor variables. The results showed that Maxent performed well, compared with modeling by CARP, at each test threshold. For all three species, the results predicted by Maxent agreed with the observed distributions in Africa and in other parts of the world. In China, C. capitata seems to have the highest number of favorable habitat areas, relative to C. cosyra and C. rosa, i.e., Yunnan, Cuizhou, Cuangxi, Guangdong, Hainan, Fujian, Sichuan and Chongqing, whereas C. cosyra has the smallest range of suitable areas, i.e., Yunnan, some parts of Hainan and Sichuan. The suitable areas for C. rosa are mainly restricted to Yunnan, Hainan, southern Cuangdong, and a few areas of Sichuan. The indications are that on the whole, Southwest and South China are the areas with the highest risk for establishment from these three fly species. Jackknife tests reveal that environmental variables associated with temperature have the strongest influence on the potential distributions of all three species relative to other variables. [ABSTRACT FROM AUTHOR]

When hybridization modifies the genetic constitution of individuals or populations, the stability of phenotypic development may either decrease or increase, depending on the divergence in the gene systems that control the development between the hybridizing taxa, i.e. on the relative effects of outbreeding and heterosis. In genetically closely related species, strong heterotic effects are less likely to occur, and hence hybridization may be expected to cause an overall decrease in developmental stability (DS) resulting from the disruption of coadapted gene complexes. To test this hypothesis, we experimentally crossed two closely related species of Ceratitis fruit flies and compared multiple-trait fluctuating asymmetry (FA, a measure of DS) in male and female offspring between parental species and two crossbred types. All traits measured play an important role in the fanning and buzzing behaviour associated with male courtship in Ceratitis, or are located on body parts involved in this behaviour. As predicted, hybrid offspring developed more asymmetrically than offspring of either parental species – most notably in meristic traits – and the increase in FA was consistently and significantly stronger in females than in males. The fact that males buffered their development more efficiently than females is in concordance with the presumed between-sex variation in functionality, and hence cost of asymmetry, of the measured traits. Absence of a similar sex difference in DS among parental offspring is believed to result from overall weak association between DS and FA in the absence of genetic stress, resulting from the random nature of the underlying processes that trigger asymmetric development. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93, 579–588. [ABSTRACT FROM AUTHOR]

Aim To predict and compare potential geographical distributions of the Mediterranean fruit fly ( Ceratitis capitata) and Natal fruit fly ( Ceratitis rosa). Location Africa, southern Europe, and worldwide. Methods Two correlative ecological niche modelling techniques, genetic algorithm for rule-set prediction (GARP) and a technique based on principal components analysis (PCA), were used to predict distributions of the two fly species using distribution records and a set of environmental predictor variables. Results The two species appear to have broadly similar potential ranges in Africa and southern Europe, with much of sub-Saharan Africa and Madagascar predicted as highly suitable. The drier regions of Africa (central and western regions of southern Africa and Sahelian zone) were identified as being less suitable for C. rosa than for C. capitata. Overall, the proportion of the region predicted to be highly suitable is larger for C. capitata than for C. rosa under both techniques, suggesting that C. capitata may be tolerant of a wider range of climatic conditions than C. rosa. Worldwide, tropical and subtropical regions are highlighted as highly suitable for both species. Differences in overlap of predictions from the two models for these species were observed. An evaluation using independent records from the adventive range for C. capitata and comparison with other predictions suggest that GARP models offer more accurate predictions than PCA models. Main conclusions This study suggests that these species have broadly similar potential distributions worldwide (based on climate), although the potential distribution appears to be broader for C. capitata than for C. rosa. Ceratitis capitata has become invasive throughout the world, whereas C. rosa has not, despite both species having broadly similar potential distributions. Further research into the biology of these species and their ability to overcome barriers is necessary to explain this difference, and to better understand invasion risk. [ABSTRACT FROM AUTHOR]

Three species of Ceratitis MacLeay are of economic importance in southern Africa. To learn more about the influence of temperature on the development of these species, the developmental rates of South African populations of Ceratitis (Ceratitis) capitata (Wiedemann), C. (Pterandrus) rosa Karsch, and C. (Ceratalaspis) costjra (Walker) were compared at constant temperatures of 14, 18, 22, 26, and 30°C. The duration of each life stage and the percentage survival of the immature life stages of each species were determined. One linear and three nonlinear developmental rate models (Briére, Lactin, and Logan-6) were found to fit the data well and were used to generate the minimum, optimum, and maximum developmental thresholds, in addition to the life cycle thermal constants for the three species. These parameter values were 9.6, 28.5, 33.0, and 338 for C. capitata, 9.7, 28.8, 33.2, and 376 for C. cosyra, and 8.6,27.7, 33.0, and 429 for C. rosa, respectively. The parameters for C. capitata are similar to those found by other researchers for this species in Reunion but the parameters for C. rosa differ substantially from published values for a Reunion population of this species, suggesting that these are different biotypes. The similarities between the developmental parameters for C. capitata and C. cosyra do not support known differences in the distribution of these species so other limiting factors such as relative humidity and the availability of host species may be important. This finding therefore cautions against basing predictions of potential global distributions of species solely on life table or climatic parameter values. [ABSTRACT FROM AUTHOR]

Understanding the strength and modes of interspecific interactions between introduced and resident species (native or previously introduced) is necessary to predict invasion success. We evaluated different mechanisms of interspecific competition among four species of polyphagous fruit flies (Diptera: Tephritidae) from the island of La Réunion: one endemic species. Ceratitis catoirii, and three exotic species, C. capitata, C. rosa, and Bactrocera zonata, that have successively invaded the island. Larval competition experiments, i.e., co-infestations of the same fruit, and behavioral interference experiments measuring the ability of one female to displace another from a fruit, were performed among all pairs of the four species. We observed asymmetric and hierarchical interactions among species in both larval and adult interference competition. In agreement with the hypothesis that invasion is competition-limited, the competitive hierarchy coincided with the temporal sequence of establishment on the island, i.e., each newly established species tended to be competitively dominant over previously established ones. [ABSTRACT FROM AUTHOR]

To evaluate its importance as a possible reservoir host of tephritid pests (Diptera) of cultivated fruit, we sampled fruit of the exotic invasive Solanum mauritianum Scop. in various sites throughout its range in central and western Kenya. Tephritids were reared from S. mauritianum wherever the plant was found, except at the highest altitudes (2,200-2,500 m). Ceratitis anonae Graham and Ceratitis fasciventris (Bezzi) were reared from fruit sampled in western Kenya. whereas the latter and Ceratitis rosa Karsch were reared from fruit found in central Kenya. In Kakamega Forest in western Kenya, C. anonae was reared from S. mauritianum year-round, whereas C. fasciventris was present in only 52.6% of the collections at this locality. A host shift by C. fasciventris onto S. mauritianum during the drier months from November to January is suggested as an explanation for the observed change in relative rates of infestation of S. mauritianum by the two Ceratitis species in western Kenya. In Nairobi (central Kenya), C. fasciventris was reared from fruit collected year-round, C. rosa was not recovered until the last of 17 Nairobi collections. In Kenya, S. mauritianum maintains year-round populations of tephritid pests available to attack cultivated fruit. S. mauritianum should be considered a noxious invasive pest in Kenya, and efforts to eradicate or control it should be made wherever it occurs. [ABSTRACT FROM AUTHOR]

A set of 10 microsatellite markers was used to survey the levels of genetic variability and to analyse the genetic aspects of the population dynamics of two potentially invasive pest fruit fly species, Ceratitis rosa and C. fasciventris, in Africa. The loci were derived from the closely related species, C. capitata. The degree of microsatellite polymorphism in C. rosa and C. fasciventris was extensive and comparable to that of C. capitata. In C. rosa, the evolution of microsatellite polymorphism in its distribution area reflects the colonization history of this species. The mainland populations are more polymorphic than the island populations. Low levels of differentiation were found within the Africa mainland area, while greater levels of differentiation affect the islands. Ceratitis fasciventris is a central–east African species. The microsatellite data over the Uganda/Kenya spatial scale suggest a recent expansion and possibly continuing gene flow within this area. The microsatellite variability data from C. rosa and C. fasciventris, together with those of C. capitata, support the hypothesis of an east African origin of the Ceratitis spp. [ABSTRACT FROM AUTHOR]

Several copies of highly related transposable elements, Crmar2, Almar1, and Asmar1, are described from the genomes of Ceratitis rosa, Anastrepha ludens, and A. suspensa, respectively. One copy from C. rosa, Crmar2.5, contains a full-length, uninterrupted ORF. All the other copies, from the three species contain a long deletion within the putative ORF. The consensus Crmar2 element has features typical of the mariner/Tc1 superfamily of transposable elements. In particular, the Crmar2 consensus encodes a D,D41D motif, a variant of the D,D34D catalytic domain of mariner elements. Phylogenetic analysis of the relationships of these three elements and other members of the mariner/Tc1 superfamily, based on their encoded amino acid sequences, suggests that they form a new basal subfamily of mariner elements, the rosa subfamily. BLAST analyses identified sequences from other diptera, including Drosophila melanogaster, which appear to be members of the rosa subfamily of mariner elements. Analyses of their molecular evolution suggests that Crmar2 entered the genome of C. rosa in the recent past, a consequence of horizontal transfer. [ABSTRACT FROM AUTHOR]

This study shows that the fruit fly, Ceratitis rosa (Karsch), has a significantly longer life span than the medfly, C. capitata (Wiedemann); the species used as a model organism for the demographics of insect aging. This was somewhat surprising given that both have similar distributions and overlapping niches. We postulate that the greater longevity of C. rosa is related to the fact that it can occupy colder habitats where the availability of suitable host plants may be very unpredictable in both time and space. [ABSTRACT FROM AUTHOR]

Abstract: The potential of entomopathogenic nematodes, Heterorhabditis bacteriophora, Heterorhabditis zealandica and Steinernema khoisanae, to infect pupariating larvae, pupae and adults of Ceratitis capitata and Ceratitis rosa was investigated in laboratory bioassays. Pupariating larvae and adult flies were susceptible to nematode infection, with no infection recorded for the pupae. Pupariating larvae of C. capitata were generally more susceptible to infection than those of C. rosa. Significantly more larvae of C. capitata were infected by H. bacteriophora. For C. rosa, highest infectivity of larvae was obtained with H. zealandica. In contrast, adults of both species were highly infected by S. khoisanae. [Copyright &y& Elsevier]