Developing an Integrated Management Approach for the Fruit Fly Dacus punctatifrons on Tomatoes

Aims: To document the various insecticides employed and also test alternative and/or complementary less-toxic and eco-friendly management methods against the notorious fruit fly Dacus punctatifrons on tomatoes as potential components of a multi-pronged eco-friendly integrated approach for this pest.

Study Design: Random interviewing of tomato farmers and field testing of different pest management methods in a randomized block design.

Place and Duration of Study: Interviewed farmers in Buea and its environs. Field experiments at the Research Farm of the University of Buea, South Western Cameroon. October 2010 to September 2011.

Methodology: Structured questionnaires administered to 110 farmers to document how they managed Dacus punctatifrons on their tomatoes and testing the efficacy of Piper guineense aqueous extract, cultural practices like staking, pruning and farm sanitation against this pest in field studies.

Results: Most of the farmers, 58(52.73%) cited Dacus punctatifrons as their main insect pest on tomatoes. All the farmers used conventional insecticides injudiciously to control the insect pests. The synthetic pyrethroid, Cypercal® 50EC was the most popular insecticide used. The numbers of fruits with fruit fly damage signs, and number of adult flies that emerged from plots treated with Piper guineense seed extract were not significantly different from those of plots treated with the neonicotinoid Parastar® 40EC insecticide. These two treatments were significantly superior to the untreated control plots and those where the plants were staked, regularly weeded and judiciously pruned. Fallen fruits and those harvested from farms even up to five weeks after farmers had harvested all marketable fruits still contained Dacus punctatifrons larvae that eventually developed into adults which emerged after laboratory incubation.

Conclusion: Integrating the judicious use of appropriately formulated insecticides, Piper guineense aqueous seed extract, early detection, collection and destruction of fruit fly-infested tomato fruits and destruction of crop residue after harvest can be a sustainable and reduced-risk multi-trigger management system for Dacus punctatifrons on tomatoes