Abstract:
Fruit flies (Diptera: Tephritidae) are listed among the major fruit pests distributed in all fruit
growing areas of the world. Fruit flies compete with human beings for food resources by
causing direct damage to fruits and vegetables. The damage they cause brings about negative
economic and social impacts to man since he depends on fruits for important food nutrients,
employment and income. The fruit fly problem in Tanzania and Africa has been aggravated
since the invasion of the new fruit fly probably of Asian origin, described as Bactrocera
invadens (Drew, Tsuruta and White). The newly invasive fruit fly that was first reported in
Kenya in 2003, then in Tanzania in 2004, thereafter from the rest of Africa, has shown ability
to spread fast within a short time as it is suspected to displace the indigenous fruit flies in the
African region. Earlier studies in Morogoro, revealed that the fruit fly does well in low to
medium altitude areas than in high altitude areas of the region. This study was conducted at
SUA horticultural unit in Morogoro, to assess the temporal and spatial presences of B.
invadens in relation to the fruiting of economically important fruit crop species. To achieve the
objective, phenological events of important fruit species and varieties were recorded while
fruit fly trapping was also done. At the same time weather parameters including temperature,
rainfall and relative humidity were recorded. The data were all recorded at weekly basis for a
period of 48 weeks. The phenology recording experiment followed a Randomized Complete
Block Design while the trapping experiment followed a split-split plot design. Fruit fly
trapping results were analysed using Genstat Statistical Package whereby Analysis of Variance
(ANOVA) was performed to determine the efficacy of attractants and the difference in fruit fly
catches between sub-orchards. The study results reveal that temperature, rainfall and relative
humidity influence phenological events in plants which as a result influence the abundance of
fruit flies and that weather has a direct impact on the population dynamics of fruit flies. It is
therefore recommended that knowledge in fruit phenology can be used as a tool in Integrated
Pest Control because of the quick response plants have to weather changes hence become
accurate timers as to when to start fighting against fruit flies for effective and inexpensive pest
management.
