Sensitivity of an enriched ginger oil based trapping system for Ceratitis fruit fly pests (Diptera: Tephritidae)

Enriched ginger oil (EGO) is a new male attractant for Ceratitis (Diptera: Tephritidae) species. The relative sensitivity of three Ceratitis pest species, C. capitata, C. rosa and C. cosyra, and their distance-dependent responses to EGO were determined using mark-release-recapture trials in three commercial fruit orchards in Mpumalanga, South Africa. Mature males of the three species (9-14 days after adult emergence) marked with fluorescent pigments were released at four distances: 25 m, 50 m, 100 m and 200 m from a centrally located white Delta trap baited with EGO. Different pigment colours were used for the different distances. Two releases were conducted in each orchard with an interval of one month between the releases. Traps were checked the following day, one week, two weeks and a month after release. Specimens captured were examined under a UV light to determine pigment colour on males of C. capitata, C. rosa and C. cosyra. There were no significant differences in recapture rates of the three Ceratitis species in the EGO baited trap. Most of the recaptures of all species occurred within a 50 m distance from the EGO baited trap. Most of the recaptures also occurred on the day following release. Based on the recapture rates obtained in this study, the probability of a trapping grid of 5 EGO baited traps per 2.59 km2 capturing one or more flies of C. capitata, C. rosa and C. cosyra for a population consisting of 1000 males for each species was estimated at over 95%. The EGO based trapping system would be an effective detection method for C. capitata, C. rosa and C. cosyra in pest free areas and in areas of low pest prevalence.