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Emergence dynamics of fruit flies and the production periods of the main hosting fruit trees in orchards of the Niayes and Thiès plateau zones (2008, Senegal).
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Introduction. Senegal produces up to 150,000 t of fruit, of which 60,000 t are mangoes. Fruit production is important for the Niayes region, where 60% of total production is of mangoes, with citrus production coming next at 24%. Mango losses have become more substantial since the arrival of Bactrocera invadens in Senegal. The pest population increa...
Citations
... Agricultural production losses due to this fly are the basis of a reduction in exports, of an increase in and of quarantine services [4] [6] [7]. In Senegal, fruit fly attacks cause yield losses of around 30% to 60% depending on the area [6]. ...
The fruit fly, Bactrocera dorsalis (Diptera: Tephritidae) is one of the most important pests in all mango-producing areas, particularly in West Africa. In Senegal, O. americanum leaves have been used for several years to control this fly. However, to our knowledge, no chemical studies have been carried out. Thus, the aim of this study is to determine the chemical composition of the essential oil of O. americanum leaves collected in Senegal and Gambia. The essential oil obtained by hydrodistillation of these leaves is analyzed by GC/FID and GC/MS. Yields of essential oils from O. americanum leaves are 3.84% and 2.13%, respectively. Analysis of these essential oils by GC/FID and GC/MS allowed the identification of 23 compounds representing almost 100% of the total compositions. These essential oils are mainly dominated by me-thyleugenol (72.0% and 75.8%, respectively). Other components in significant percent are trans-β-caryophyllene (13.9% and 13.0%, respectively), germacrene D (4.1% and 3.7%, respectively), β-elemene (3.3% and 0.9%, respectively). Due to the high methyleugenol content, this study explains the attractive potential of O. americanum towards B. dorsalis. In perspective, we plan to evaluate the attractive effect of the essential oil and leaf powder of O. ameri-canum against B. dorsalis, a real pest of mango orchards in Senegal.
... The function 'networklevel' of the 'bipartite' package (Dormann et al., 2008(Dormann et al., , 2009) was used to determine indices describing networks Badii et al., 2015;Franck & Delatte, 2020;Goergen et al., 2011;Moquet et al., 2021;Mwatawala et al., 2006;Ndiaye et al., 2012;Rattanapun, 2009;Rwomushana et al., 2008;Vargas et al., 2007;Zida et al., 2020. T values. ...
The oriental fruit fly ( Bactrocera dorsalis ) is one of the world's most invasive and polyphagous fruit pests. It causes severe damage throughout its range and can devastate the entire fruit harvest in unprotected orchards. In 2007, B. dorsalis was detected in Mayotte, where it now ranks ninth on the list of fruit fly species of economic importance. This tropical island is a good study area to analyse the host range of B. dorsalis and its interactions with other resident fruit fly species.
Two field campaigns were carried out from 2012 to 2014 and from 2019 to 2021. We collected fruit from all over the island in cultivated and non‐cultivated areas and compared the infestation rates between the two periods.
We detected six fruit fly species, including the common species Dacus ciliatus, Neoceratitis cyanescens, Ceratitis capitata, B. dorsalis and two rarer species, Dacus etiennellus and Trirhithrum nigerrimum.
The most surprising result was the low occurrence of B. dorsalis, with only seven host plant species identified out of a total of 84 plant species. Infestation rates were low for these host plant species, even in the case of mango (11.71 flies/kg) and Indian almond (0.97 fly/kg), which are considered to be major host plants of B. dorsalis .
Bactrocera dorsalis seems to have a lower impact in Mayotte than in other parts of the world. We discuss the possible causes of the weak infestation rates observed, which could provide the key to regulating the species on the island.
... Agricultural production losses due to this fly are the basis of a reduction in exports, of an increase in and of quarantine services [4] [6] [7]. In Senegal, fruit fly attacks cause yield losses of around 30% to 60% depending on the area [6]. ...
The fruit fly, Bactrocera dorsalis (Diptera: Tephritidae) is one of the most important pests in all mango-producing areas, particularly in West Africa. In Senegal, O. americanum leaves have been used for several years to control this fly. However, to our knowledge, no chemical studies have been carried out. Thus, the aim of this study is to determine the chemical composition of the essential oil of O. americanum leaves collected in Senegal and Gambia. The essential oil obtained by hydrodistillation of these leaves is analyzed by GC/FID and GC/MS. Yields of essential oils from O. americanum leaves are 3.84% and 2.13%, respectively. Analysis of these essential oils by GC/FID and GC/MS allowed the identification of 23 compounds representing almost 100% of the total compositions. These essential oils are mainly dominated by me-thyleugenol (72.0% and 75.8%, respectively). Other components in significant percent are trans-β-caryophyllene (13.9% and 13.0%, respectively), germacrene D (4.1% and 3.7%, respectively), β-elemene (3.3% and 0.9%, respectively). Due to the high methyleugenol content, this study explains the attractive potential of O. americanum towards B. dorsalis. In perspective, we plan to evaluate the attractive effect of the essential oil and leaf powder of O. ameri-canum against B. dorsalis, a real pest of mango orchards in Senegal.
... Agricultural production losses due to this fly are the basis of a reduction in exports, of an increase in and of quarantine services [4] [6] [7]. In Senegal, fruit fly attacks cause yield losses of around 30% to 60% depending on the area [6]. ...
The fruit fly, Bactrocera dorsalis (Diptera: Tephritidae) is one of the most important pests in all mango-producing areas, particularly in West Africa. In Senegal, O. americanum leaves have been used for several years to control this fly. However, to our knowledge, no chemical studies have been carried out. Thus, the aim of this study is to determine the chemical composition of the essential oil of O. americanum leaves collected in Senegal and Gambia. The essential oil obtained by hydrodistillation of these leaves is analyzed by GC/FID and GC/MS. Yields of essential oils from O. americanum leaves are 3.84% and 2.13%, respectively. Analysis of these essential oils by GC/FID and GC/MS allowed the identification of 23 compounds representing almost 100% of the total compositions. These essential oils are mainly dominated by me-thyleugenol (72.0% and 75.8%, respectively). Other components in significant percent are trans-β-caryophyllene (13.9% and 13.0%, respectively), germacrene D (4.1% and 3.7%, respectively), β-elemene (3.3% and 0.9%, respectively). Due to the high methyleugenol content, this study explains the attractive potential of O. americanum towards B. dorsalis. In perspective, we plan to evaluate the attractive effect of the essential oil and leaf powder of O. ameri-canum against B. dorsalis, a real pest of mango orchards in Senegal.
... A key factor could be the survival of small demes during the dry season that would constitute discreet sources to initiate local population growth and rapid reinfestation of orchards at the beginning of the production season. Many abiotic and biotic factors have been identified as potentially critical for the survival of BD during the mango off-season in Senegal, including temperature, precipitations, relative humidity, irrigation as well as the abundance, diversity and phenology of alternative host plants within and around orchards (Diallo et al., 2021;Dieng et al., 2019;Boinahadji et al., 2019;Konta et al., 2015;Vayssières et al., 2015;Diatta et al., 2013;Ndiaye et al., 2012;Ndiaye et al., 2008). ...
... The study area encompassed the "Niayes" (Fig. 2), which is the main region of vegetable and fruit production in Senegal (Grechi et al., 2013;De Bon et al., 1997). Mango is the main fruit production, grew either in intensive orchards dedicated to international export or in more traditional and diversified orchards for local markets (Ndiaye et al., 2012;Vayssières et al., 2011). The harvest season in the Niayes, which is subject to a Sahelian climate, is mainly from June to August and coincides with the rainy season (Grechi et al., 2013;Vayssières et al., 2011). ...
... inter-crops as presence/absence. Host diversity and frequency, which may also influence BD re-infestation dynamics (Diallo et al., 2021;Boinahadji et al., 2019;Diatta 2016;Grechi et al., 2013;Ndiaye et al., 2012;Vayssières et al., 2011), were also estimated from a subset of around 100 fruit trees per orchard. Each selected tree was identified at the species level and for mango trees, the cultivar was also identified. ...
Implementing integrated pest management programs to limit agricultural pest damage requires an understanding of the interactions between the environmental variability and population demographic processes. However, identifying key environmental drivers of spatiotemporal pest population dynamics remains challenging as numerous candidate factors can operate at a range of scales, from the field (e.g. agricultural practices) to the regional scale (e.g. weather variability). In such a context, data-driven approaches applied to pre-existing data may allow identifying patterns, correlations, and trends that may not be apparent through more restricted hypothesis-driven studies. The resulting insights can lead to the generation of novel hypotheses and inform future experimental work focusing on a limited and relevant set of environmental predictors. In this study, we developed an ecoinformatics approach to unravel the multi-scale environmental conditions that lead to the early re-infestation of mango orchards by a major pest in Senegal, the oriental fruit fly Bactrocera dorsalis (BD). We gathered abundance data from a three-year monitoring conducted in 69 mango orchards as well as environmental data (i.e. orchard management, landscape structure and weather variability) across a range of spatial scales. We then developed a flexible analysis pipeline centred on a recent machine learning algorithm (GPBoost), which allows the combination of gradient boosting and mixed-effects models or Gaussian processes, to hierarchize the effects of multi-scale environmental variables on the timing of annual BD population growth in orchards. We found that physical factors (temperature, humidity), and to some extent landscape features, were the main drivers of the spatio-temporal variability of the onset of population growth in orchards. These results suggest that favourable microclimate conditions could provide refuges for small BD populations that could survive, with little or no reproduction, during the mango off-season and, then, recolonize neighbouring orchards at the beginning of the next mango season. Confirmation of such a hypothesis could help to prioritize surveillance and preventive control actions in refuge areas.
... The only citrus species listed as a host plant for C. cosyra was Citrus aurantium L. and the record was classified as questionable, since identity of the specimens could not be verified (De Meyer et al. 2002). In surveys done after the publication of this host plant list and following the introduction of B. dorsalis in several parts in Africa, C. cosyra was recorded from some citrus types in East and West Africa (Mwatawala et al. 2009, Ndiaye et al. 2012). However, these records did not always provide full details on the origin and conditions (damaged, not damaged) of the citrus fruit from which C. cosyra was reared (Mwatawala et al. 2009, Ndiaye et al. 2012. ...
... In surveys done after the publication of this host plant list and following the introduction of B. dorsalis in several parts in Africa, C. cosyra was recorded from some citrus types in East and West Africa (Mwatawala et al. 2009, Ndiaye et al. 2012). However, these records did not always provide full details on the origin and conditions (damaged, not damaged) of the citrus fruit from which C. cosyra was reared (Mwatawala et al. 2009, Ndiaye et al. 2012. In both of these studies, there was at least one other fruit fly species reared from the same citrus fruit as C. cosyra (Mwatawala et al. 2009, Ndiaye et al. 2012) and a question of opportunistic oviposition behavior by the species using punctures made by other fruit fly species can be raised. ...
... However, these records did not always provide full details on the origin and conditions (damaged, not damaged) of the citrus fruit from which C. cosyra was reared (Mwatawala et al. 2009, Ndiaye et al. 2012. In both of these studies, there was at least one other fruit fly species reared from the same citrus fruit as C. cosyra (Mwatawala et al. 2009, Ndiaye et al. 2012) and a question of opportunistic oviposition behavior by the species using punctures made by other fruit fly species can be raised. Although C. cosyra is not considered a pest of commercial citrus in South Africa, to address any potentially remaining phytosanitary concerns, it was deemed useful to determine whether existing cold disinfestation protocols for fruit fly pests of citrus in South Africa would be equally effective against C. cosyra. ...
The efficacy of an existing cold disinfestation postharvest treatment targeting Ceratitis capitata (Wiedemann) in citrus was determined for the marula fly, Ceratitis cosyra (Walker). The cold tolerances of C. capitata and C. cosyra were first quantified in artificial diet at 3.5 °C at different exposure periods for up to 18 days. Ceratitis capitata was found to be more cold tolerant than C. cosyra. At 3.5 °C, the duration to achieve 99.9968% mortality was calculated to be 11.57 days for C. capitata and 9.10 days for C. cosyra. Under an existing C. capitata cold treatment schedule at 1 °C for 14 days, the conditions required for complete mortality of the third larval stage of C. cosyra in orange, Citrus sinensis (L.) Osbeck cv. Valencia, were then determined. No survivors of C. cosyra in oranges were recorded beyond 11 days of cold treatment at 1 °C. The efficacy of this C. capitata treatment for disinfestation of C. cosyra was thereafter confirmed in large scale trials in Valencia oranges. In the large-scale trial at the lowest mean temperature of 1.19 °C for 14 days, there were no survivors from a total of 85 490 treated C. cosyra third instars in oranges. Since C. capitata was shown to be more cold tolerant than C. cosyra and a large scale test demonstrated at least 99.9965% efficacy after 14 days at 1.19 °C, compared with the established effective C. capitata cold treatment of 14 days at 1.11 °C, cold disinfestation treatments for C. capitata should be at least equally effective against C. cosyra.
... Bactrocera dorsalis causes extensive economic losses to horticultural crops throughout sub-Saharan Africa (Ekesi et al., 2006;Vayssières et al., 2009). In Senegalese mango orchards, fruit damages attributable to fruit flies were estimated at 30-50 % in the Niayes area and 60 % in the Casamance (Ndiaye et al., 2012;Diamé et al., 2015). However, conservation of weaver ants as an effective biological control agent is greatly limited by its adverse effects (Van Mele et al., 2009b;Anato et al., 2015). ...
The use of predatory arthropods in biological pest control in agriculture can generate resistance by farmers when these beneficials become noxious for them or their crops. The African weaver ant, Oecophylla longinoda (Hymenoptera: Formicidae), an effective biocontrol agent of pests, particularly Bactrocera dorsalis fruit flies in mango orchards in West Africa, is a good example of such inconveniences. We here explored whether manipulating their behavior by providing sugar feeders on trees would (i) alter their mutualistic relationships with scale insects, thereby reducing the incidence of this pest, (ii) decrease nest abundance often considered by farmers to reduce foliage development, and (iii) reduce their aggressiveness. To that end, a field monitoring was launched in an organic mango orchard in Senegal wherein three treatments were compared: (1) mango trees with ants and sugar feeder, (2) mango trees with ants but no sugar feeder, and (3) mango trees with neither ants nor sugar feeder. The population dynamics of scale insects and weaver ants as well as their behavior were monitored over two years. Sugar provisioning significantly reduced scale insect infestations, nest abundance, and ant aggressiveness over time. Such manipulation of ant behavior through sugar supplementation should help breaking down obstacles that hamper their wide-scale use for the biological control of fruit flies in mango orchards.
... In Senegal, along with citrus fruits, mango represents a very important part of horticultural production (60 and 24% respectively) (Ndiaye et al., 2012). However, this production has faced many challenges of a phytosanitary nature and in recent years more particularly various phytophagous pests including the oriental fruit fly Bactrocera dorsalis (Hendel, 1912) (Diptera : Tephritidae) . ...
... This expansion could also be explained by the fact that several species of the Tephritidae family are very mobile travelers, they engage in large dispersive movements during the period of search to host plants, mating and maturation, which means that its genetic structure is linked to the locality and not to the host plant. According to Ndiaye et al. (2012) and Ndimanya and Strebelle, (2013) the distribution of the species would be due to the production of mangoes in Senegal which has existed for a long time in traditional form, especially in regions with a vocation for fruit production, in orchards and in planting at the level of family farms as well as small and medium farmers. These orchards, located mostly in the south of the country, with local varieties of host plants not benefiting from irrigation or adequate cultivation techniques, favor the multiplication and dispersal of the species. ...
Objectives: the study examines the effect of the host plant and of the agro-ecological area on the genetic structure of populations of Bactrocera dorsalis in order to apprehend an appropriate period to fight this pest. Methodology and results: this study was conducted in two large areas mango productions Senegal (area Niayes and the forest area South) on 41 individuals of Bactrocera dorsalis with mitochondrial gene sequencing (cytochrome B). Several haplotypes (28) of which 27 individual have been identified with a high level of genetic diversity (Hd 0.972 and Pi 0.1563). The genetic demo tests suggested a population in equilibrium, a moderate expansion and a grouping according to the areas thus revealing a genetic structure linked to the localities. In addition, the haplotype network showed a majority haplotype comprising all areas, 24 individual haplotypes and a typical haplotype to Notto. Conclusion and application of findings : this exploratory study was in addition to having provided information on the genetic characterization of the species Bactrocera dorsalis , describes its structure and its genetic differentiation based on two areas-ecological where mango is practically cultivated in Senegal. It helped to understand the genetic identity card of the species Bactrocera dorsalis, whose purpose will be to know its weakest link and food preferences to provide alternative struggles.
... Their results have shown the prevalency of 18 fruit fly species, namely Bactrocera invadens (Drew Tsuruta -White) (current Bactrocera dorsalis), B. cucurbitae (Coquillett), Ceratitis cosyra (Walker), C. silvestrii (Bezzi), D. longistilus (Bezzi), C. fasciventris (Bezzi), C. capitata (Wiedemann), C. ditissima (Munro), C. anonae (Graham), C. bremii (Guérin-Méneville), C. punctata (Wiedemann), C. flexuosa (Walker), Dacus ciliatus (Loew), D. vertebratus (Bezzi), D. bivittatus (Bigot), D. guineensis ( Hering), D. xanthinus (White -Goodger) and D. velutifrons (White -Goodger). Two similar and more recent studies have been carried out by Konta et al. (2001) and Ndiaye et al. (2012) [12,18] . The first had reported B. invadens, Ceratitis cosyra, C. capitata, C. punctata, C. bremii, Bactrocera cucurbitae, Capparimyia bipustulata, Carpomyia sp and Dacus sp as the 8 species collected in the Niayes area; while the second mentionned the inventory of 12 species in Casamance, including B. dorsalis, B. cucurbitae, Dacus vertebratus, Dacus ciliatus, Dacus frontalis, Dacus longistylus, C. cosyra, C. fascivientris, C. bremii, C. capitata, Themarictera flaveolata and Ceratitis sp. ...
... Their results have shown the prevalency of 18 fruit fly species, namely Bactrocera invadens (Drew Tsuruta -White) (current Bactrocera dorsalis), B. cucurbitae (Coquillett), Ceratitis cosyra (Walker), C. silvestrii (Bezzi), D. longistilus (Bezzi), C. fasciventris (Bezzi), C. capitata (Wiedemann), C. ditissima (Munro), C. anonae (Graham), C. bremii (Guérin-Méneville), C. punctata (Wiedemann), C. flexuosa (Walker), Dacus ciliatus (Loew), D. vertebratus (Bezzi), D. bivittatus (Bigot), D. guineensis ( Hering), D. xanthinus (White -Goodger) and D. velutifrons (White -Goodger). Two similar and more recent studies have been carried out by Konta et al. (2001) and Ndiaye et al. (2012) [12,18] . The first had reported B. invadens, Ceratitis cosyra, C. capitata, C. punctata, C. bremii, Bactrocera cucurbitae, Capparimyia bipustulata, Carpomyia sp and Dacus sp as the 8 species collected in the Niayes area; while the second mentionned the inventory of 12 species in Casamance, including B. dorsalis, B. cucurbitae, Dacus vertebratus, Dacus ciliatus, Dacus frontalis, Dacus longistylus, C. cosyra, C. fascivientris, C. bremii, C. capitata, Themarictera flaveolata and Ceratitis sp. ...
... According to Reitz et al. (2002) [20] diversity that is observed between very close species is generally a result of invasions of exotic species. Based on previous localized studies, the ten species identified during this study are different to the 18 species that were found by Vayssières et al. (2002) [30] in the Niayes, the 12 species inventoried by Konta et al. (2015) [12] in Casamance and those from Ndiaye et al. (2012) [18] who reported the presence of eight (8) species of Tephritidae in Casamance. We noted that 99.98% of the fruit fly populations are composed of B. dorsalis, C. silvestrii, C. cosyra, Z. curcurbitae and C. capitata. ...
... In Senegal, citrus fruits are mainly grown in the Niayes Zone and Casamance areas and comprise a wide range of fruit crops. Although very dynamic, the sector is permanently threatened by various emerging pests, among which are tephritid fruit flies (Ndiaye et al. 2012). The Tephritidae family comprises of 4000 species belonging to 500 genera, and constitutes one of the most economically significant insect groups (Ekesi et al. 2011). ...
... The Tephritidae family comprises of 4000 species belonging to 500 genera, and constitutes one of the most economically significant insect groups (Ekesi et al. 2011). Ceratitis cosyra (Walker), C. fasciventris, C. rosa, C. anonae, C. capitata were the most prominent species before the arrival of the oriental or Asian invasive fruit fly, Bactrocera dorsalis (Hendel), on the continent (Ndiaye et al. 2008(Ndiaye et al. , 2012Vayssières et al. 2012;Ekesi et al. 2016). Initially reported in 2003 in Kenya, B. dorsalis spread very rapidly in several countries (Lux et al. 2003;Schutze et al. 2017). ...
... In addition to direct losses in orchards, fruit flies are responsible for the destruction of many mango export consignments, annually, from West Africa to Europe (De Meyer et al. 2009). In Senegal, crop losses attributable to B dorsalis are estimated at 40-60% in the Niayes region, and up to 70-80% in the South in Casamance (Vayssières et al. 2011;Ndiaye et al. 2012). Losses due to fruit flies seriously affect the livelihoods of producers and actors in the sector, including vendors, retailers, negotiators, sellers, exporters, and food processors (Grechi et al. 2013;Maertens 2009). ...
The effectiveness of the "attract and kill" approach for the management of Bactrocera dorsalis in citrus orchards using autoinoculation strategy was evaluated in three locations in Senegal (Sindia, Sébikhotane and Ndoyene), between 2016 and 2018. Attractant Contaminant Traps (ACT) were treated with 0.3 g of Metarhizium acridum, and methyl eugenol was then deployed at densities of 25, 50 and 100 ACT to infect the flies. Recovery Traps (RT) containing methyl eugenol and a toxicant, Timaye were used to monitor the B. dorsalis population and the contamination rate. Results showed that the rate of contaminated flies increases with the number of ACT, at an average daily rate of contaminated flies of 68.1%, 85.44% and 99.67% at 25, 50, 100 traps, respectively. No contaminated flies were found in the control. The number of flies caught decreased from 21.7, 4.2 and 6.2 flies per day, respectively, for 25, 50, 100 ACTs and control in the first week, to 0.64, 0.71, 0.71 and 99.9 flies per day, respectively, for 25, 50, 100 ACTs and the control. All the flies caught at M. acridum treated sites were contaminated. No significant difference between the incidence of fruit damage in the three ACT densities and the control was found in the first week; however, there was a significant difference over time, from 90.0, 96.7 and 83.3% in the first week, to 30, 50 and 46.7% at the 14th week, respectively, for 25, 50 and 100 ACTs. No significant differences were found in the control. This present study demonstrated the efficacy of autoinoculative systems based-M. acridum for the management of B. dorsalis in citrus orchards in Senegal. This strategy is economical as it uses very little amounts of inoculum with locally made materials.
