Seasonality and range of fruit fly (Diptera: Tephritidae) host plants in orchards in Niayes and the Thiès Plateau (Senegal)

Abstract

Seasonality and range of fruit fly (Diptera: Tephritidae) host plants in orchards in Niayes and the Thiès Plateau (Senegal).Abstract -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 increases in the mango ripening period, but little is known about its secondary hosts. Materials and methods. Fruits of cultivated and wild plants were collected regularly from April to December 2008 inside and around 19 orchards in eleven localities in the Niayes and Thiès areas in Senegal. The samples were monitored to identify any fruit flies present so that a list of host plants could be compiled. For mango, the study focused on establishing the influence of certain parameters such as the variety, the fruit size, the color, the flowering pattern and the physiological levels of infestation due to B. invadens and Ceratitis cosyra. Orchards were classified either as traditional (many mango varieties and many fruit species grown together in a stand) or intensive (fields of monovarietal mango trees), according to their composition and how they were managed. Results and discussion. A total of 663.2 kg of fruit, including those of 24 mango varieties, 13 citrus species with five lime varieties, two orange varieties and four pomelo varieties along with other cultivated and wild plants, were sampled both as fallen fruit and from the trees. Traditional orchards were more infested than the modern ones. B. invadens was significantly dominant over the other flies emerging such as C. cosyra, C. capitata, C. punctata, C. bremii, Bactrocera cucurbitae, Capparimyia bipustulata, Carpomyia sp. and Dacus sp. B. invadens was found on the 24 varieties of Mangifera indica, the 13 citrus species, and the other cultivated plants and wild plants sampled. Some host plants supported a relatively high level of fruit flies before the mango ripening period. Mangifera indica was infested principally by B. invadens and C. cosyra. C. cosyra was significantly present on the first fruit trees to flower, mostly in early varieties, while B. invadens infested all the varieties whatever the fruit development stage, the color, or the flowering pattern. Conclusion. Because of the host plants' diversity and varieties the traditional orchards were more infested than the modern ones. The management of this pest needs an Integrated Pest Management system based on a back-to-basics study of the infesting fruit flies, existing parasitoids and their hosts.Senegal / fruit crops / host plants / Mangifera indica / Citrus / Tephritidae / Bactrocera invadens / Ceratitis cosyra / orchards / sampling Saisonnalité et gamme des mouches des fruits (Tephritidae, diptères) identifiées dans les plantes hôtes des vergers des Niayes et du plateau de Thiès (Sénégal).Résumé -Introduction. La production fru...

Annual population dynamics of mango fruit flies (Diptera: Tephritidae) in West Africa: socio-economic aspects, host phenology and implications for management

“…For mid-and late mango cultivars, Bactrocera invadens caused more than 90% of the damage in both Southern Sudan and Northern Sudan zones [4,27]. In the Sahelian zone (in Senegal-Niayes), Bactrocera invadens was considered to be the principal pest for mangoes during the rainy season [3,10,28]. Previous studies J.-F. Vayssières et al indicated that, in the Forest zone [29,30] and in the Guinean Savanna zone (GuineaKindia [31]), the impact of B. invadens was high during the whole mango season.…”

“…The mango exports from West Africa were estimated at between 35 000 t and 40 000 t, equivalent to US$ 45 M [2]. In Senegal, for example, the production of fruits was estimated at 150 000 t per year, of which 60 000 t are mango alone [1,3], with 6 000 t exported to the European Union (EU). Africa has the potential to increase mango quality and the volume of exports, and competes against the main world mango exporters for the European market.…”

Mango-based orchards in Senegal: diversity of design and management patterns

“…Vayssières et al identified four types of systems in West Africa: the "gatherer production system", "production system under improvement", "more intensive production system" and "large industrialized orchards" [9]. In two other studies carried out in the Niayes region in Senegal, Vayssières et al simply differentiated between "mixed (pluri-specific)" and "homogeneous (monospecific) orchards" [6], while Ndiaye et al differentiated between "traditional" and "modern (intensive) orchards" [10]. However, these approaches were not based on a comprehensive and quantitative analysis of both the orchard designs issuing from farmers' planting choices and the agricultural practices the farmers use for current orchard management.…”

“…[17][18][19][20]. Regarding mango production, only some studies have outlined system characterizations, which focused primarily on the level of intensification of cropping systems [6,9] and the composition of the orchards [10]. Vayssières et al identified four types of systems in West Africa: the "gatherer production system", "production system under improvement", "more intensive production system" and "large industrialized orchards" [9].…”

“…The mango sector in Senegal has high development potential, but an improvement of the mango-based cropping systems is needed to overcome their high production and quality irregularities. Mango-based cropping systems in West African countries are highly varied, from gatherer and pluri-specific orchards to intensive mono-specific orchards [2,6,[8][9][10]. Even though this diversity is generally known, a thorough knowledge of the current systems and their functioning is still lacking for stakeholders' concern with improvement of Senegalese mango production.…”