Abstract:
Managed populations of weaver ants in mango trees have been used successfully in Australia, SE Asia and parts
of Western Africa to deter fruit flies from ovipositing in ripening fruits. The presence of indigenous weaver ants
in mango trees of smallholder growers in Tanzania offers the possibility of exploiting them as an affordable,
environmentally friendly method to improve marketable fruit yield and quality. In a preliminary interview study
in a m ango growing region of rural Tanzania, the farmers were not convinced of any beneficial, deterrent effect
attributable to the indigenous weaver ants in their trees and were sceptical of any likely value as a biological
control technique. Additionally, frui t fly infestation was not seen as a priority problem and subsequent enquiry
and investigation showed that, fortuitously, traditional, local practices for storage and enhancing ripening
prevented the development of a significant proportion of any deposited eggs. Subsequent field studies supported
the grower perceptions as they recorded only an erratic and limited deterrent effect.
