Management of Fruit flies in Oman via Application of Different Cultural, Chemical and Biological Methods

Fruit flies are major pests of fruits of fruit trees and cucurbits in Oman. The significant damage they cause on fruits has become a major concern to farmers, especially farmers of the AlBatinah Farmers Association. Due to the lack of stringent application of quarantine laws, a number of fruit fly species were possibly introduced and became invasive in the last 48 years (e.g. peach-guava fruit fly). Due to their aggressive nature, lack of effective natural enemies, and change in habits of rural people in Oman in the last 60 years, populations of these fruit flies increased rapidly causing destruction of fruits and diminishing yields from fruit and vegetable farms. The impact of fruit flies on farmers is of great concern due to the ability of these pests to damage fruits on many different crops, whether fruit trees or herbaceous vegetables (such as cucurbits). It can be estimated that at least 30-40% of the fruit produced in Oman is destroyed by fruit flies. Two species of fruit flies are confirmed to be regular and severe pests of fruits in Oman. Bactrocera zonata damages fruits of different fruit trees such as citrus, mango, guava, and ber (sidr). There is also Dacus ciliatus which damages various cucurbits. Insecticide sprays have been used in the past in Oman, but they are not viable/ sustainable due to concerns about residues, resistance, and banning of many insecticides in Oman. Therefore, the general objectives of the project revolve around the investigation of effective non-chemical tactics for fruit fly management in Oman. This project aims to evaluate extracts of different local wild plants, weeds, and cultivated plants as potential repellents/oviposition deterrents for the aforementioned pest fruit flies. Additionally, plant extracts will be screened as effective lures for females of the two same pest fruit flies. Commercially available formulations of a number of species of entomopathogens will be evaluated for effectiveness against soil-borne stages of the two fruit fly species. The most promising repellents/oviposition deterrents, lures, and formulations of entompathogens will be tested in the field along with other available management approaches in both fruit tree orchard and cucurbit agroe-ecosystems. Many of these management approaches will be completely novel to Oman. For fruit trees, experiments will be conducted to test the efficacy of sanitation, mulching, protein lure trapping, and kaolin. Additionally, for cucurbits, experiments will be conducted to test the efficacy of agryl row covers. Moreover, parasitic wasps will be released and evaluated for their establishment and effect on populations of the two pest fruit flies in a fruit orchard and cucurbit field in AlBatinah South, with the expectation that these parasitic wasps will eventually establish and spread to adjacent orchards and fields. It is expected that the project will establish new methods of fruit fly management with the most effective methods to be applied in the future in an integrated manner over area-wide scale. It is hoped results of this research project if adopted on an area-wide scale to dramatically increase production of fruits free of fruit fly infestation. This in turn is expected to lower fruit prices for local consumer and improve general quality of food in Oman and also allow the export of quality fruits to countries in the region and beyond.