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.